The Director serves as a versatile network service designed to redirect incoming HTTP(s) requests to the optimal host or Content Delivery Network (CDN) by evaluating various request properties through a set of rules. Although requests can be generic, the primary focus centers around audio-video content delivery. The rule engine allows users to construct routing configurations using predefined blocks, providing for the creation of intricate routing logic. This modular approach allows the users to tailor and streamline the content delivery process to meet their specific needs. The Director’s flexible rule engine takes into account factors such as geographical location, server load, content type, and other metadata from external sources to intelligently route incoming requests. It supports dynamic adjustments to seamlessly adapt to changing network conditions, ensuring efficient and reliable content delivery. The Director improves the overall user experience by delivering content from the most suitable and responsive sources, thereby reducing latency and enhancing performance.

Requirements

Hardware

The Director is designed to be installed and operated on commodity hardware, ensuring accessibility for a broad range of users. The minimum hardware specifications are as follows:

CPU: x86-64 AMD or Intel with at least 2 cores.
Memory: At least 2 GB free at runtime.

Operating System Compatibility

The Director is officially supported on Red Hat Enterprise Linux 8 or 9 or any compatible operating system. In order to run the service, a minimum CPU architecture of x86-64-v2 is required. This can be determined by running the following command. If supported, it will be listed as “(supported)” in the output.

/usr/lib64/ld-linux-x86-64.so.2 --help | grep x86-64-v2

External Internet access is necessary during the installation process for the installer to download and install additional dependencies. This ensures a seamless setup and optimal functionality of the Director on Red Hat Enterprise Linux 8 or 9. It’s worth noting that, due to the unique workings of the DNF package manager in Red Hat Enterprise Linux with rolling package streams, an air-gapped installation process is not available.

Firewall Recommendations

See Firewall.

Installation

See Installation.

Operations

See Operations.

Configuration Process

Once the router is operational, it requires a valid configuration before it can route incoming requests.

There are currently three methods available for configuring the router, each catering to different levels of complexity. The first is a Web UI, suitable for the most common use-cases, providing an intuitive interface for configuration. The second involves utilizing a confd REST service, complemented by an optional command line tool, confcli, suitable for all but the most advanced scenarios. The third method involves leveraging an internal REST API, ideal for the most intricate cases where using confd proves to be less flexible. It’s essential to note that as the configuration method advances through these levels, both flexibility and complexity increase, providing users with tailored options based on their specific needs and expertise.

API Key Management

Regardless of the method used to configure the system, a unique API key is crucial for safeguarding the router’s configuration and preventing unauthorized access to the API. This key must be supplied when interacting with the API. During the router software installation, an automatically generated API key is created and can be located on the installed system at /opt/edgeware/acd/router/cache/rest-api-key.json. The structure of this file is as follows:

{"api_key": "abc123"}

When accessing the internal configuration API, the key must be included in the X-API-key header of the request, as shown below:

curl -v -k -H "X-API-Key: abc123" https://<router-host.example>:5001/v2/configuration

Modification to the authentication key and behavior can be done through the /v2/rest_api_key endpoint. To change the key, a PUT request with a JSON body of the same structure can be sent to the endpoint:

curl -v -k -X PUT -T new-key.json -H "X-API-Key: abc123" \
-H "Content-Type: application/json" https://<router-host.example>:5001/v2/rest_api_key

Additionally, key authentication can be disabled completely by sending a DELETE request to the endpoint:

curl -v -k -X DELETE -H "X-API-Key: abc123" \
https://<router-host.example>:5001/v2/rest_api_key

In the event of a lost or forgotten authentication key, it can always be retrieved at /opt/edgeware/acd/router/cache/rest-api-key.json on the machine running the router. It is critical to emphasize that the API key should remain private to prevent unauthorized access to the internal API, as it grants full access to the router’s configuration.

Configuration Basics

Upon completing the installation process and configuring the API keys, the subsequent section will provide guidance on configuring the router to route all incoming requests to a single host. For straightforward CDN Offload use cases, there is a web based user interface described here.

For further details on configuring the router using confd and confcli, please consult the Confd documentation.

The initial step involves defining the target host group. In this illustration, a singular group named all will be established, comprising two hosts.

$ confcli services.routing.hostGroups -w
Running wizard for resource 'hostGroups'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

hostGroups : [
  hostGroup can be one of
    1: dns
    2: host
    3: redirecting
  Choose element index or name: host
  Adding a 'host' element
    hostGroup : {
      name (default: ): all
      type (default: host):
      httpPort (default: 80):
      httpsPort (default: 443):
      hosts : [
        host : {
          name (default: ): host1.example.com
          hostname (default: ): host1.example.com
          ipv6_address (default: ):
        }
        Add another 'host' element to array 'hosts'? [y/N]: y
        host : {
          name (default: ): host2.example.com
          hostname (default: ): host2.example.com
          ipv6_address (default: ):
        }
        Add another 'host' element to array 'hosts'? [y/N]: n
      ]
    }
  Add another 'hostGroup' element to array 'hostGroups'? [y/N]: n
]
Generated config:
{
  "hostGroups": [
    {
      "name": "all",
      "type": "host",
      "httpPort": 80,
      "httpsPort": 443,
      "hosts": [
        {
          "name": "host1.example.com",
          "hostname": "host1.example.com",
          "ipv6_address": ""
        },
        {
          "name": "host2.example.com",
          "hostname": "host2.example.com",
          "ipv6_address": ""
        }
      ]
    }
  ]
}
Merge and apply the config? [y/n]:

After defining the host group, the next step is to establish a rule that directs incoming requests to the designated host. In this example, a sole rule named random will be generated, ensuring that all incoming requests are consistently routed to the previously defined host.

$ confcli services.routing.rules -w
Running wizard for resource 'rules'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

rules : [
  rule can be one of
    1: allow
    2: consistentHashing
    3: contentPopularity
    4: deny
    5: firstMatch
    6: random
    7: rawGroup
    8: rawHost
    9: split
    10: weighted
  Choose element index or name: random
  Adding a 'random' element
    rule : {
      name (default: ): random
      type (default: random):
      targets : [
        target (default: ): host1.example.com
        Add another 'target' element to array 'targets'? [y/N]: y
        target (default: ): host2.example.com
        Add another 'target' element to array 'targets'? [y/N]: n
      ]
    }
  Add another 'rule' element to array 'rules'? [y/N]: n
]
Generated config:
{
  "rules": [
    {
      "name": "random",
      "type": "random",
      "targets": [
        "host1.example.com",
        "host2.example.com"
      ]
    }
  ]
}
Merge and apply the config? [y/n]:

The last essential step involves instructing the router on which rule should serve as the entry point into the routing tree. In this example, we designate the rule random as the entrypoint for the routing process.

$ confcli services.routing.entrypoint random
services.routing.entrypoint = 'random'

Once this configuration is defined, all incoming requests will initiate their traversal through the routing rules, starting with the rule named random. This rule is designed to consistently match for every incoming request, effectively load balancing evenly between host1.example.com and host2.example.com on port 80 or 443, depending on whether the initial request was made using HTTP or HTTPS.

Integration with Convoy

The router is equipped with the capability to synchronize specific configuration metadata with a separate Convoy installation through the integrated convoy-bridge service. However, this service necessitates additional setup and configuration, and you can find comprehensive details on the process here..

Additional Resources

Additional documentation resources are included with the Director and can be accessed at the following directory: /opt/edgeware/acd/documentation/. This directory contains supplementary materials to provide users with comprehensive information and guidance for optimizing their experience with the Director.

Ready for Production

Once the Director software is completely installed and configured, there are a few additional considerations before moving to a full production environment. See the section Ready for Production for additional information.

2 - Installation

How to install and upgrade ESB3024 Router

2.1 - Installing a 1.14 release

How to install and upgrade to ESB3024 Router release 1.14.x

To install ESB3024 Router, one first needs to copy the installation ISO image to the target node where the router will be run. Due to the way the installer operates, it is necessary that the host is reachable by password-less SSH from itself for the user account that will perform the installation, and that this user has sudo access.

Prerequisites:

Ensure that the current user has sudo access.
```
sudo -l
```
If the above command fails, you may need to add the user to the /etc/sudoers file.
Ensure that the installer has password-less SSH access to localhost.
If using the root user, the PermitRootLogin property of the /etc/ssh/sshd_config file must be set to ‘yes’.
The local host key must also be included in the .ssh/authorized_keys file of the user running the installer. That can be done by issuing the following as the intended user:
```
mkdir -m 0700 -p ~/.ssh
ssh-keyscan localhost >> ~/.ssh/authorized_keys
```
Note! The ssh-keyscan utility will result in the key fingerprint being output on the console. As a security best-practice it is recommended to verify that this host-key matches the machine’s true SSH host key. As an alternative, to this ssh-keyscan approach, establishing an SSH connection to localhost and accepting the host key will have the same result.
Disable SELinux.
The Security-Enhanced Linux Project (SELinux) is designed to add an additional layer of security to the operating system by enforcing a set of rules on processes. Unfortunately out of the box the default configuration is not compatible with the way the installer operates. Before proceeding with the installation, it is recommended to disable SELinux. It can be re-enabled after the installation completes, if desired, but will require manual configuration. Refer to the Red Hat Customer Portal for details.
To check if SELinux is enabled:
```
getenforce
```
This will result in one of 3 states, “Enforcing”, “Permissive” or “Disabled”. If the state is “Enforcing” use the following to disable SELinux. Either “Permissive” or “Disabled” is required to continue.
```
setenforce 0
```
This disables SELinux, but does not make the change persistent across reboots. To do that, edit the /etc/selinux/config file and set the SELINUX property to disabled.
It is recommended to reboot the computer after changing SELinux modes, but the changes should take effect immediately.

Assuming the installation ISO image is in the current working directory, the following steps need to be executed either by root user or with sudo.

Mount the installation ISO image under /mnt/acd.
Note: The mount-point may be any accessible path, but /mnt/acd will be used throughout this document.
```
mkdir -p /mnt/acd
mount esb3024-acd-router-1.14.0.iso /mnt/acd
```
Run the installer script.
```
/mnt/acd/installer
```

Upgrade from and earlier ESB3024 Router release

The following steps can be used to upgrade the router from a 1.10 or 1.12 release to 1.14.0. If upgrading from an earlier release it is recommended to first upgrade to 1.10.1 in multiple steps; for instance when upgrading from release 1.8.0 to 1.14.0, it is recommended to first upgrade to 1.10.1 and then to 1.14.0.

The upgrade procedure for the router is performed by taking a backup of the configuration, installing the new release of the router, and applying the saved configuration.

With the router running, save a backup of the configuration.
The exact procedure to accomplish this depends on the current method of configuration, e.g. if confd is used, then the configuration should be extracted from confd, but if the REST API is used directly, then the configuration must be saved by fetching the current configuration snapshot using the REST API.
Extracting the configuration using confd is the recommend approach where available.
```
confcli | tee config_backup.json
```
To extract the configuration from the REST API, the following may be used instead. Depending on the version of the router used, an API-Key may be required to fetch from the REST API.
```
curl --insecure https://localhost:5001/v2/configuration \
  | tee config_backup.json
```
If the API Key is required, it can be found in the file /opt/edgeware/acd/router/cache/rest-api-key.json and can be passed to the API by setting the value of the X-API-Key header.
```
curl --insecure -H "X-API-Key: 1234abcd" \
  https://localhost:5001/v2/configuration \
  | tee config_backup.json
```
Mount the new installation ISO under /mnt/acd.
Note: The mount-point may be any accessible path, but /mnt/acd will be used throughout this document.
```
mkdir -p /mnt/acd
mount esb3024-acd-router-1.14.0.iso /mnt/acd
```
Stop the router and all associated services.
Before upgrading the router it needs to be stopped, which can be done by typing this:
```
systemctl stop 'acd-*'
```
Run the installer script.
```
/mnt/acd/installer
```
Migrate the configuration.
Note that this step only applies if the router is configured using confd. If it is configured using the REST API, this step is not necessary.
The confd configuration used in the previous versions is not directly compatible with 1.14, and may need to be converted. If this is not done, the configuration will not be valid and it will not be possible to make configuration changes.
The acd-confd-migration tool will automatically apply any necessary schema migrations. Further details about this tool can be found at Confd Auto Upgrade Tool.
The tool takes as input the old configuration file, either by reading the file directly, or by reading from standard input, applies any necessary migrations between the two specified versions, and outputs a new configuration to standard output which is suitable for being applied to the upgraded system. While the tool has the ability to migrate between multiple versions at a time, the earliest supported version is 1.10.1.
The example below shows how to upgrade from 1.10.2. If upgrading from 1.12.0, --from 1.10.2 should be replaced with --from 1.12.0.
The command line required to run the tool is different depending on which esb3024 release it is run on. On 1.14.0 it is run like this:
```
cat config_backup.json | \
  podman run -i --rm \
  images.edgeware.tv/acd-confd-migration:1.14.0 \
  --in - --from 1.10.2 --to 1.14.0 \
  | tee config_upgraded.json
```
After running the above command, apply the new configuration to confd by running cat config_upgraded.json | confcli -i.

Troubleshooting

If there is a problem running the installer, additional debug information can be output by adding -v or -vv or -vvv to the installer command, the more “v” characters, the more detailed output.

2.1.1 - Configuration changes between 1.12.1 and 1.14

This describes the configuration changes between ESB3024 Router version 1.12.1 and 1.14.x

Confd configuration changes

Below are the changes to the confd configuration between versions 1.12.1 and 1.14.x listed.

Renamed `services.routing.settings.allowedProxies`

The configuration setting services.routing.settings.allowedProxies has been renamed to services.routing.settings.trustedProxies.

Added `services.routing.tuning.general.restApiMaxBodySize`

This parameter configures the maximum body size for the REST API. It mainly applies to the configuration, which sometimes has a large payload size.

2.2 - Installing a 1.12 release

How to install and upgrade to ESB3024 Router release 1.12.0 and 1.12.1

Prerequisites:

Ensure that the current user has sudo access.
```
sudo -l
```
If the above command fails, you may need to add the user to the /etc/sudoers file.
Ensure that the installer has password-less SSH access to localhost.
If using the root user, the PermitRootLogin property of the /etc/ssh/sshd_config file must be set to ‘yes’.
The local host key must also be included in the .ssh/authorized_keys file of the user running the installer. That can be done by issuing the following as the intended user:
```
mkdir -m 0700 -p ~/.ssh
ssh-keyscan localhost >> ~/.ssh/authorized_keys
```
Note! The ssh-keyscan utility will result in the key fingerprint being output on the console. As a security best-practice its recommended to verify that this host-key matches the machine’s true SSH host key. As an alternative, to this ssh-keyscan approach, establishing an SSH connection to localhost and accepting the host key will have the same result.
Disable SELinux.
The Security-Enhanced Linux Project (SELinux) is designed to add an additional layer of security to the operating system by enforcing a set of rules on processes. Unfortunately out of the box the default configuration is not compatible with the way the installer operates. Before proceeding with the installation, it is recommended to disable SELinux. It can be re-enabled after the installation completes, if desired, but will require manual configuration. Refer to the Red Hat Customer Portal for details.
To check if SELinux is enabled:
```
getenforce
```
This will result in one of 3 states, “Enforcing”, “Permissive” or “Disabled”. If the state is “Enforcing” use the following to disable SELinux. Either “Permissive” or “Disabled” is required to continue.
```
setenforce 0
```
This disables SELinux, but does not make the change persistent across reboots. To do that, edit the /etc/selinux/config file and set the SELINUX property to disabled.
It is recommended to reboot the computer after changing SELinux modes, but the changes should take effect immediately.

Assuming the installation ISO image is in the current working directory, the following steps need to be executed either by root user or with sudo.

Mount the installation ISO image under /mnt/acd.
Note: The mount-point may be any accessible path, but /mnt/acd will be used throughout this document.
```
mkdir -p /mnt/acd
mount esb3024-acd-router-esb3024-1.12.1.iso /mnt/acd
```
Run the installer script.
```
/mnt/acd/installer
```

Upgrade from ESB3024 Router release 1.10

The following steps can be used to upgrade the router from a 1.10 release to 1.12.0 or 1.12.1. If upgrading from an earlier release it is recommended to perform the upgrade in multiple steps; for instance when upgrading from release 1.8.0 to 1.12.1, it is recommended to first upgrade to 1.10.1 or 1.10.2 and then to 1.12.1.

The upgrade procedure for the router is performed by taking a backup of the configuration, installing the new release of the router, and applying the saved configuration.

With the router running, save a backup of the configuration.
The exact procedure to accomplish this depends on the current method of configuration, e.g. if confd is used, then the configuration should be extracted from confd, but if the REST API is used directly, then the configuration must be saved by fetching the current configuration snapshot using the REST API.
Extracting the configuration using confd is the recommend approach where available.
```
confcli | tee config_backup.json
```
To extract the configuration from the REST API, the following may be used instead. Depending on the version of the router used, an API-Key may be required to fetch from the REST API.
```
curl --insecure https://localhost:5001/v2/configuration \
  | tee config_backup.json
```
If the API Key is required, it can be found in the file /opt/edgeware/acd/router/cache/rest-api-key.json and can be passed to the API by setting the value of the X-API-Key header.
```
curl --insecure -H "X-API-Key: 1234abcd" \
  https://localhost:5001/v2/configuration \
  | tee config_backup.json
```
Mount the new installation ISO under /mnt/acd.
Note: The mount-point may be any accessible path, but /mnt/acd will be used throughout this document.
```
mkdir -p /mnt/acd
mount esb3024-acd-router-esb3024-1.12.1.iso /mnt/acd
```
Stop the router and all associated services.
Before upgrading the router it needs to be stopped, which can be done by typing this:
```
systemctl stop 'acd-*'
```
Run the installer script.
```
/mnt/acd/installer
```
Migrate the configuration.
Note that this step only applies if the router is configured using confd. If it is configured using the REST API, this step is not necessary.
The confd configuration used in the 1.10 versions is not directly compatible with 1.12, and may need to be converted. If this is not done, the configuration will not be valid and it will not be possible to make configuration changes.
To help with migrating the configuration, a new tool has been included in the 1.12.0 release, which will automatically apply any necessary schema migrations. Further details about this tool can be found here. Confd Auto Upgrade.
The confd-auto-upgrade tool takes as input the old configuration file, either by reading the file directly, or by reading from standard input, applies any necessary migrations between the two specified versions, and outputs a new configuration to standard output which is suitable for being applied to the upgraded system. While the tool has the ability to migrate between multiple versions at a time, the earliest supported version is 1.10.1.
The example below shows how to upgrade from 1.10.2. If upgrading from 1.10.1, --from 1.10.2 should be replaced with --from 1.10.1.
The command line required to run the tool is different if it is run on esb3024-1.12.0 or esb3024-1.12.1. On 1.12.1 it is run like this:
```
cat config_backup.json | \
  podman run -i --rm \
  images.edgeware.tv/auto-upgrade-esb3024-1.12.1-master:20240702T151205Z-f1b53a98f \
  --in - --from 1.10.2 --to 1.12.1 \
  | tee config_upgraded.json
```
On esb3024-1.12.0 it is run like this:
```
cat config_backup.json | \
  podman run -i --rm \
  images.edgeware.tv/auto-upgrade-esb3024-1.12.0:20240619T154952Z-2b72f7400 \
  --in - --from 1.10.2 --to 1.12.0 \
  | tee config_upgraded.json
```
After running the above command, apply the new configuration to confd by running cat config_upgraded.json | confcli -i.

Troubleshooting

2.2.1 - Configuration changes between 1.10.2 and 1.12

This describes the configuration changes between ESB3024 Router version 1.10.2 and 1.12.0/1.12.1.

Confd configuration changes

Below are the major changes to the confd configuration between versions 1.10.2 and 1.12.0/1.12.1. Note that there are no configuration changes between versions 1.12.0 and 1.12.1, so the differences apply to both.

Added `services.routing.translationFunctions.hostRequest`

A new translation function has been added which will allow custom Lua code to modify requests to backend hosts before they are sent.

Added `services.routing.translationFunctions.session`

A new translation function has been added which will allow custom Lua code to be executed after the router has made the routing decision but before generating the redirect URL.

An example use case would be for enabling instream sessions, which can be done by setting this value to return set_session_type('instream').

Removed `services.routing.settins.managedSessions` configuration

This configuration is no longger used.

Added `services.routing.tuning.general.maxActiveManagedSessions` tuning parameter.

This parameter configures the maximum number of active managed sessions.

2.3 - Installing release 1.10.x

How to install and upgrade to ESB3024 Router release 1.10.x

Prerequisites:

Ensure that the current user has sudo access.
```
sudo -l
```
If the above command fails, you may need to add the user to the /etc/sudoers file.
Ensure that the installer has password-less SSH access to localhost.
If using the root user, the PermitRootLogin property of the /etc/ssh/sshd_config file must be set to ‘yes’.
The local host key must also be included in the .ssh/authorized_keys file of the user running the installer. That can be done by issuing the following as the intended user:
```
mkdir -m 0700 -p ~/.ssh
ssh-keyscan localhost >> ~/.ssh/authorized_keys
```
Note! The ssh-keyscan utility will result in the key fingerprint being output on the console. As a security best-practice its recommended to verify that this host-key matches the machine’s true SSH host key. As an alternative, to this ssh-keyscan approach, establishing an SSH connection to localhost and accepting the host key will have the same result.
Disable SELinux.
The Security-Enhanced Linux Project (SELinux) is designed to add an additional layer of security to the operating system by enforcing a set of rules on processes. Unfortunately out of the box the default configuration is not compatible with the way the installer operates. Before proceeding with the installation, it is recommended to disable SELinux. It can be re-enabled after the installation completes, if desired, but will require manual configuration. Refer to the Red Hat Customer Portal for details.
To check if SELinux is enabled:
```
getenforce
```
This will result in one of 3 states, “Enforcing”, “Permissive” or “Disabled”. If the state is “Enforcing” use the following to disable SELinux. Either “Permissive” or “Disabled” is required to continue.
```
setenforce 0
```
This disables SELinux, but does not make the change persistent across reboots. To do that, edit the /etc/selinux/config file and set the SELINUX property to disabled.
It is recommended to reboot the computer after changing SELinux modes, but the changes should take effect immediately.

Assuming the installation ISO image is in the current working directory, the following steps need to be executed either by root user or with sudo.

Mount the installation ISO image under /mnt/acd.
Note: The mount-point may be any accessible path, but /mnt/acd will be used throughout this document.
```
mkdir -p /mnt/acd
mount esb3024-acd-router-esb3024-1.10.1.iso /mnt/acd
```
Run the installer script.
```
/mnt/acd/installer
```

Upgrade from ESB3024 Router release 1.8.0

The following steps can be used to upgrade the router from release 1.8.0 to 1.10.x. If upgrading from an earlier release it is recommended to perform the upgrade in multiple steps; for instance when upgrading from release 1.6.0 to 1.10.x, it is recommended to first upgrade to 1.8.0 and then to 1.10.x.

The upgrade procedure for the router is performed by taking a backup of the configuration, installing the new release of the router, and applying the saved configuration.

With the router running, save a backup of the configuration.
The exact procedure to accomplish this depends on the current method of configuration, e.g. if confd is used, then the configuration should be extracted from confd, but if the REST API is used directly, then the configuration must be saved by fetching the current configuration snapshot using the REST API.
Extracting the configuration using confd is the recommend approach where available.
```
confcli | tee config_backup.json
```
To extract the configuration from the REST API, the following may be used instead. Depending on the version of the router used, an API-Key may be required to fetch from the REST API.
```
curl --insecure https://localhost:5001/v2/configuration \
  | tee config_backup.json
```
If the API Key is required, it can be found in the file /opt/edgeware/acd/router/cache/rest-api-key.json and can be passed to the API by setting the value of the X-API-Key header.
```
curl --insecure -H "X-API-Key: 1234abcd" \
  https://localhost:5001/v2/configuration \
  | tee config_backup.json
```
Mount the new installation ISO under /mnt/acd.
Note: The mount-point may be any accessible path, but /mnt/acd will be used throughout this document.
```
mkdir -p /mnt/acd
mount esb3024-acd-router-esb3024-1.10.1.iso /mnt/acd
```
Stop the router and all associated services.
Before upgrading the router it needs to be stopped, which can be done by typing this:
```
systemctl stop 'acd-*'
```
Run the installer script.
```
/mnt/acd/installer
```
Migrate the configuration.
Note that this step only applies if the router is configured using confd. If it is configured using the REST API, this step is not necessary.
The confd configuration used in version 1.8.0 is not directly compatible with 1.10.x, and may need to be converted. If this is not done, the configuration will not be valid and it will not be possible to make configuration changes.
To determine if the configuration needs to be converted, confcli can be run like below. If it prints error messages, the configuration needs to be converted. If no error messages are printed, the configuration is valid and no further updates are necessary.
```
confcli | head -n5
[2024-04-02 14:48:37,155] [ERROR] Missing configuration key /integration
[2024-04-02 14:48:37,162] [ERROR] Missing configuration key /services/routing/settings/qoeTracking
[2024-04-02 14:48:37,222] [ERROR] Missing configuration key /services/routing/hostGroups/convoy-rr/hosts/convoy-rr-1/healthChecks
[2024-04-02 14:48:37,222] [ERROR] Missing configuration key /services/routing/hostGroups/convoy-rr/hosts/convoy-rr-2/healthChecks
[2024-04-02 14:48:37,242] [ERROR] Missing configuration key /services/routing/hostGroups/e-dns/hosts/linton-dns-1/healthChecks
{
   "integration": {
      "convoy": {
            "bridge": {
               "accounts": {
```
If error messages are printed, the configuration needs to be converted. If the configuration was saved in the file config_backup.json, the conversion can be done by typing this at the command line:
```
sed -E -e '/"hosts":/,/]/ s/([[:space:]]+)("hostname":.*)/\1\2\n\1"healthChecks": [],/' -e '/"apiKey":/ d' config_backup.json | \
curl -s -X PUT -T - -H 'Content-Type: application/json' http://localhost:5000/config/__active/
```
```
systemctl restart acd-confd
```
This adds empty healthChecks sections to all hosts and removes the apiKey configuration. After that, acd-confd is restarted. See Configuration changes between 1.8.0 and 1.10.x for more details about the configuration changes.
Migrating configuration to esb3024-1.10.2
When upgrading to version 1.10.2, an extra step is required to migrate the consistent hashing configuration. This step is necessary both when upgrading from an earlier 1.10 release and when upgrading from older versions. It is only needed if consistent hashing was configured in the previous version.
To determine if consistent hashing was configured, execute the following command:
```
confcli | head -n2
[2024-05-31 09:43:55,932] [ERROR] Missing configuration key /services/routing/rules/constantine/hashAlgorithm
{
    "integration": {
```
If an error message about a missing configuration key appears, the configuration must be migrated. If no such error message appears, this step should be skipped.
To migrate the configuration, execute the following command at the command line:
```
curl -s http://localhost:5000/config/__active/ | \
sed -E 's/(.*)("type":.*"consistentHashing")(,?)/\1\2,\n\1"hashAlgorithm": "MD5"\3/' | \
curl -s -X PUT -T - -H 'Content-Type: application/json' http://localhost:5000/config/__active/
```
This command will read the current configuration, add the hashAlgorithm configuration key, and write back the updated configuration.
Remove the Account Monitor container
Older versions of the router installed the Account Monitor tool. This was removed in release 1.8.0, but if it is still present and unused, it can be removed by typing:
```
podman rm account-monitor
```
Remove the confd-transformer.lua file
After installing or upgrading to 1.10.x, ensure that the confd-transformer.lua script located in /opt/edgeware/acd/router/lib/standard_lua directory is removed.
This file contains deprecated Lua language definitions which will override newer versions of those functions already present in the ACD Router’s Lua Standard Library. When upgrading beyond 1.10.2, the installer will automatically remove this file, however for this particular release, it requires manual intervention.
```
rm -f /opt/edgeware/acd/router/lib/standard_lua/confd-transformer.lua
```
After removing this file, it will be necessary to restart the router to flush the definitions from the router’s memory:
```
systemctl restart acd-router
```

Troubleshooting

2.3.1 - Configuration changes between 1.8.0 and 1.10.x

This describes the configuration changes between ESB3024 Router version 1.8.0 and 1.10.x.

Confd configuration changes

Below are the major changes to the confd configuration between version 1.8.0 and 1.10.x listed.

Added `integration.convoy` section

An integration.convoy section has been added to the configuration. It is currently used for configuring the Convoy Bridge service.

Removed `services.routing.apiKey` configuration

The services.routing.apiKey configuration key has been removed. This was an obsolete way of giving the configuration access to the router. The key has to be removed from the configuration when upgrading, otherwise the configuration will not be accepted.

Added `services.routing.settings.qoeTracking`

A services.routing.settings.qoeTracking section has been added to the configuration.

Added `healthChecks` sections to the hosts

The hosts in the hostGroup entries have been extended with a healthChecks key, which is a list of functions that determine if a host is in good health.

For example, a redirecting host might look like this after the configuration has been updated:

{
    "services": {
        "routing": {
            "hostGroups": [
                {
                    "name": "convoy-rr",
                    "type": "redirecting",
                    "httpPort": 80,
                    "httpsPort": 443,
                    "forwardHostHeader": true,
                    "hosts": [
                        {
                            "name": "convoy-rr-1",
                            "hostname": "convoy-rr-1",
                            "ipv6_address": "",
                            "healthChecks": [
                                "health_check('convoy-rr-1')"
                            ]
                        }
                    ]
                }
            ],

Added `hashAlgorithm` to the `consistentHashing` rule

In esb3024-1.10.2 the consistentHashing routing rule has been extended with a hashAlgorithm key, which can have the values MD5, SDBM and Murmur. The default value is MD5.

2.4 - Installing release 1.8.0

How to install and upgrade to ESB3024 Router release 1.8.0

Prerequisites:

Ensure that the current user has sudo access.
```
sudo -l
```
If the above command fails, you may need to add the user to the /etc/sudoers file.
Ensure that the installer has password-less SSH access to localhost.
If using the root user, the PermitRootLogin property of the /etc/ssh/sshd_config file must be set to ‘yes’.
The local host key must also be included in the .ssh/authorized_keys file of the user running the installer. That can be done by issuing the following as the intended user:
```
mkdir -m 0700 -p ~/.ssh
ssh-keyscan localhost >> ~/.ssh/authorized_keys
```
Note! The ssh-keyscan utility will result in the key fingerprint being output on the console. As a security best-practice its recommended to verify that this host-key matches the machine’s true SSH host key. As an alternative, to this ssh-keyscan approach, establishing an SSH connection to localhost and accepting the host key will have the same result.
Disable SELinux.
The Security-Enhanced Linux Project (SELinux) is designed to add an additional layer of security to the operating system by enforcing a set of rules on processes. Unfortunately out of the box the default configuration is not compatible with the way the installer operates. Before proceeding with the installation, it is recommended to disable SELinux. It can be re-enabled after the installation completes, if desired, but will require manual configuration. Refer to the Red Hat Customer Portal for details.
To check if SELinux is enabled:
```
getenforce
```
This will result in one of 3 states, “Enforcing”, “Permissive” or “Disabled”. If the state is “Enforcing” use the following to disable SELinux. Either “Permissive” or “Disabled” is required to continue.
```
setenforce 0
```
It is recommended to reboot the computer after changing SELinux modes, but the changes should take effect immediately.

Assuming the installation ISO image is in the current working directory, the following steps need to be executed either by root user or with sudo.

Mount the installation ISO image under /mnt/acd.
Note: The mount-point may be any accessible path, but /mnt/acd will be used throughout this document.
```
mkdir -p /mnt/acd
mount esb3024-acd-router-esb3024-1.8.0.iso /mnt/acd
```
Run the installer script.
```
/mnt/acd/installer
```

Upgrade

The upgrade procedure for the router is performed by taking a backup of the configuration, installing the new version of the router, and applying the saved configuration.

With the router running, save a backup of the configuration.
The exact procedure to accomplish this depends on the current method of configuration, e.g. if confd is used, then the configuration should be extracted from confd, but if the REST API is used directly, then the configuration must be saved by fetching the current configuration snapshot using the REST API.
Extracting the configuration using confd is the recommend approach where available.
```
confcli | tee config_backup.json
```
To extract the configuration from the REST API, the following may be used instead. Depending on the version of the router used, an API-Key may be required to fetch from the REST API.
```
curl --insecure https://localhost:5001/v2/configuration \
  | tee config_backup.json
```
If the API Key is required, it can be found in the file /opt/edgeware/acd/router/cache/rest-api-key.json and can be passed to the API by setting the value of the X-API-Key header.
```
curl --insecure -H "X-API-Key: 1234abcd" \
  https://localhost:5001/v2/configuration \
  | tee config_backup.json
```
Mount the new installation ISO under /mnt/acd.
Note: The mount-point may be any accessible path, but /mnt/acd will be used throughout this document.
```
mkdir -p /mnt/acd
mount esb3024-acd-router-1.2.0.iso /mnt/acd
```
Stop the router and all associated services.
Before upgrading the router it needs to be stopped, which can be done by typing this:
```
systemctl stop 'acd-*'
```
Run the installer script.
```
/mnt/acd/installer
```
Migrate the configuration.
Note that this step only applies if the router is configured using confd. If it is configured using the REST API, this step is not necessary.
The confd configuration used in version 1.6.0 is not directly compatible with 1.8.0, and may need to have a few minor manual updates in order to be valid. If this is not done, the configuration will not be valid and it will not be possible to make configuration changes.
To determine if the configuration needs to be manually updated, confcli can be run like below. If it prints error messages, the configuration needs to be updated. If no error messages are printed, the configuration is valid and no further updates are necessary.
```
confcli services.routing | head
[2024-02-01 19:05:10,769] [ERROR] Missing configuration key /services/routing/hostGroups/convoy-rr/forwardHostHeader
[2024-02-01 19:05:10,779] [ERROR] Missing configuration key /services/routing/hostGroups/e-dns/forwardHostHeader
[2024-02-01 19:05:10,861] [ERROR] 'forwardHostHeader'
```
If error messages are printed, a forwardHostHeader configuration needs to be added to the hostGroups configuration. This can be done by running this at the command line:
```
curl -s http://localhost:5000/config/__active/ | \
sed -E 's/([[:space:]]+)"type": "(host|redirecting|dns)"(,?)/\1"type": "\2",\n\1"forwardHostHeader": false\3/' | \
curl -s -X PUT -T - -H 'Content-Type: application/json' http://localhost:5000/config/__active/
```
This reads the active configuration from the router, adds the “forwardHostHeader” configuration to all host groups, and then sends the updated configuration back to the router.
See Configuration changes between 1.6.0 and 1.8.0 for more details about the configuration changes.
Remove the Account Monitor container
Previous versions of the router installed the Account Monitor tool. This is no longer included, but since the previous version installed, there will be a stopped Account Monitor container. If it is not used, the container can be removed by typing:
```
podman rm account-monitor
```

Troubleshooting

2.4.1 - Configuration changes between 1.6.0 and 1.8.0

This describes the configuration changes between ESB3024 Router version 1.6.0 and 1.8.0.

Confd configuration changes

Below are some of the configuration changes between version 1.4.0 and 1.6.0 listed. The list only contains the changes that might affect already existing configuration, enirely new items are not listed. Normally nothing needs to be done about this since they will be upgraded automatically, but they are listed here for reference.

Added `enabled` to `contentPopularity`

An enabled key has been added to services.routing.settings.contentPopularity. After the key has been added, the configuration looks like this:

{
    "services": {
        "routing": {
            "settings": {
                "contentPopularity": {
                    "enabled": true,
                    "algorithm": "score_based",
                    "sessionGroupNames": []
                },
                ...

Added `selectionInputItemLimit` to `tuning`

A selectionInputItemLimit key has been added to services.routing.tuning.general. After the key has been added, the configuration looks like this:

{
    "services": {
        "routing": {
            "tuning": {
                "general": {
                    ...
                    "selectionInputItemLimit": 10000,
                    ...

Added `forwardHostHeader` to `hostGroups`

All three hostGroup types (host, redirecting and dns) have been extended with a forwardHostHeader key. For example, a redirecting host might look like this after the change:

{
    "services": {
        "routing": {
            "hostGroups": [
                {
                    "name": "convoy-rr",
                    "type": "redirecting",
                    "httpPort": 80,
                    "httpsPort": 443,
                    "forwardHostHeader": true,
                    "hosts": [
                        {
                            "name": "convoy-rr-1",
                            "hostname": "convoy-rr-1",
                            "ipv6_address": ""
                        }
                    ]
                }
            ],
            ...

REST API configuration changes

The following items have been added to the REST API configuration. They will not need to be manually updated, the router will add the new keys with default values. Note that this is not a complete list of all changes, it only contains the changes that will be automatically added when upgrading the router.

If the router is configured via confd and confcli, these changes will be applied by them. This section is only relevant if the router is configured via the v2/configuration API.

Added the session_translation_function key.
Added the tuning.selection_input_item_limit key.

2.5 - Installing release 1.6.0

How to install and upgrade to ESB3024 Router release 1.6.0

Prerequisites:

Ensure that the current user has sudo access.
```
sudo -l
```
If the above command fails, you may need to add the user to the /etc/sudoers file.
Ensure that the installer has password-less SSH access to localhost.
If using the root user, the PermitRootLogin property of the /etc/ssh/sshd_config file must be set to ‘yes’.
The local host key must also be included in the .ssh/authorized_keys file of the user running the installer. That can be done by issuing the following as the intended user:
```
mkdir -m 0700 -p ~/.ssh
ssh-keyscan localhost >> ~/.ssh/authorized_keys
```
Note! The ssh-keyscan utility will result in the key fingerprint being output on the console. As a security best-practice its recommended to verify that this host-key matches the machine’s true SSH host key. As an alternative, to this ssh-keyscan approach, establishing an SSH connection to localhost and accepting the host key will have the same result.
Disable SELinux.
The Security-Enhanced Linux Project (SELinux) is designed to add an additional layer of security to the operating system by enforcing a set of rules on processes. Unfortunately out of the box the default configuration is not compatible with the way the installer operates. Before proceeding with the installation, it is recommended to disable SELinux. It can be re-enabled after the installation completes, if desired, but will require manual configuration. Refer to the Red Hat Customer Portal for details.
To check if SELinux is enabled:
```
getenforce
```
This will result in one of 3 states, “Enforcing”, “Permissive” or “Disabled”. If the state is “Enforcing” use the following to disable SELinux. Either “Permissive” or “Disabled” is required to continue.
```
setenforce 0
```
It is recommended to reboot the computer after changing SELinux modes, but the changes should take effect immediately.

Assuming the installation ISO image is in the current working directory, the following steps need to be executed either by root user or with sudo.

Mount the installation ISO image under /mnt/acd.
Note: The mount-point may be any accessible path, but /mnt/acd will be used throughout this document.
```
mkdir -p /mnt/acd
mount esb3024-acd-router-esb3024-1.8.0.iso /mnt/acd
```
Run the installer script.
```
/mnt/acd/installer
```

Upgrade

The upgrade procedure for the router is performed by taking a backup of the configuration, installing the new version of the router, and applying the saved configuration.

With the router running, save a backup of the configuration.
The exact procedure to accomplish this depends on the current method of configuration, e.g. if confd is used, then the configuration should be extracted from confd, but if the REST API is used directly, then the configuration must be saved by fetching the current configuration snapshot using the REST API.
Extracting the configuration using confd is the recommend approach where available.
```
confcli | tee config_backup.json
```
To extract the configuration from the REST API, the following may be used instead. Depending on the version of the router used, an API-Key may be required to fetch from the REST API.
```
curl --insecure https://localhost:5001/v2/configuration \
  | tee config_backup.json
```
If the API Key is required, it can be found in the file /opt/edgeware/acd/router/cache/rest-api-key.json and can be passed to the API by setting the value of the X-API-Key header.
```
curl --insecure -H "X-API-Key: 1234abcd" \
  https://localhost:5001/v2/configuration \
  | tee config_backup.json
```
Mount the new installation ISO under /mnt/acd.
Note: The mount-point may be any accessible path, but /mnt/acd will be used throughout this document.
```
mkdir -p /mnt/acd
mount esb3024-acd-router-1.2.0.iso /mnt/acd
```
Stop the router and all associated services.
Before upgrading the router it needs to be stopped, which can be done by typing this:
```
systemctl stop 'acd-*'
```
Run the installer script.
```
/mnt/acd/installer
```
Migrate the configuration.
Note that this step only applies if the router is configured using confd. If it is configured using the REST API, this step is not necessary.
See Configuration changes between 1.4.0 and 1.6.0 for instructions on how to migrate the configuration to release 1.6.0.

Troubleshooting

2.5.1 - Configuration changes between 1.4.0 and 1.6.0

This describes the configuration changes between ESB3024 Router version 1.4.0 and 1.6.0.

confd configuration

The confd configuration used in version 1.4.0 is not directly compatible with 1.6.0, and will need to have a few minor updates in order to be valid. If this is not done, the configuration will not be valid and it will not be possible to make configuration changes. Running confcli will cause error messages and an empty default configuration to be printed.

$ confcli services.routing.
[2023-12-12 16:08:07,120] [ERROR] Missing configuration key /services/routing/translationFunctions
[2023-12-12 16:08:07,122] [ERROR] Missing configuration key /services/routing/settings/instream/dashManifestRewrite/sessionGroupNames
[2023-12-12 16:08:07,122] [ERROR] Missing configuration key /services/routing/settings/instream/hlsManifestRewrite/sessionGroupNames
[2023-12-12 16:08:07,123] [ERROR] Missing configuration key /services/routing/settings/managedSessions
[2023-12-12 16:08:07,123] [ERROR] Missing configuration key /services/routing/tuning/target/recentDurationMilliseconds
{
    "routing": {
        "apiKey": "",
        "settings": {
            "allowedProxies": [],
            "contentPopularity": {
                "algorithm": "score_based",
                "sessionGroupNames": []
            },
            "extendedContentIdentifier": {
            ...

The first thing that needs to be done is to rename the keys sessionGroupIds to sessionGroupNames. If the configuration was backed up to the file config_backup.json before upgrading, the keys can be renamed and the updated configuration can be applied by typing this:

sed 's/"sessionGroupIds"/"sessionGroupNames"/' config_backup.json | confcli -i
[2023-12-19 12:33:17,725] [ERROR] Missing configuration key /services/routing/translationFunctions
[2023-12-19 12:33:17,726] [ERROR] Missing configuration key /services/routing/settings/instream/dashManifestRewrite/sessionGroupNames
[2023-12-19 12:33:17,727] [ERROR] Missing configuration key /services/routing/settings/instream/hlsManifestRewrite/sessionGroupNames
[2023-12-19 12:33:17,727] [ERROR] Missing configuration key /services/routing/settings/managedSessions
[2023-12-19 12:33:17,727] [ERROR] Missing configuration key /services/routing/tuning/target/recentDurationMilliseconds

The configuration has not yet been converted, so the error messages are still printed. The configuration will be converted when the acd-confd service is restarted.

systemctl restart acd-confd

This concludes the conversion of the configuration and the router is ready to be used.

Configuration changes

Below are all configuration changes between version 1.4.0 and 1.6.0 listed. Normally nothing needs to be done about this since they will be upgraded automatically, but they are listed here for reference.

Added `translationFunctions` block

services.routing.translationFunctions has been added. It can be added as a map with two empty strings as values, to make the top of the configuration look like this:

{
    "services": {
        "routing": {
            "translationFunctions": {
                "request": "",
                "response": ""
            },
            ...

Renamed `sessionGroupIds` to `sessionGroupNames`

The keys services.routing.settings.instream.dashManifestRewrite.sessionGroupIds and services.routing.settings.instream.hlsManifestRewrite.sessionGroupIds have been renamed to services.routing.settings.instream.dashManifestRewrite.sessionGroupNames and services.routing.settings.instream.hlsManifestRewrite.sessionGroupNames respectively. Any session group IDs need to be manually converted to session group names.

After the conversion, the head of the configuration file might look like this:

{
    "services": {
        "routing": {
            "apiKey": "",
            "settings": {
                "allowedProxies": [],
                "contentPopularity": {
                    "algorithm": "score_based",
                    "sessionGroupNames": []
                },
                "extendedContentIdentifier": {
                    "enabled": false,
                    "includedQueryParams": []
                },
                "instream": {
                    "dashManifestRewrite": {
                        "enabled": false,
                        "sessionGroupNames": []
                    },
                    "hlsManifestRewrite": {
                        "enabled": false,
                        "sessionGroupNames": []
                    },
                    "reversedFilenameComparison": false
                },
                ...

Added `managedSessions` block

A services.routing.settings.managedSessions block has been added. After adding the block, the configuration might look like this:

{
    "services": {
        "routing": {
            "apiKey": "",
            "settings": {
                "allowedProxies": [],
                "contentPopularity": {
                    "algorithm": "score_based",
                    "sessionGroupNames": []
                },
                ...
                "managedSessions": {
                    "fraction": 0.0,
                    "maxActive": 100000,
                    "sessionTypes": []
                },
                "usageLog": {
                    "enabled": false,
                    "logInterval": 3600000
                }
            },
            ...

Added `recentDurationMilliseconds`

A services.routing.tuning.target.recentDurationMilliseconds key has been added to the configuration file, with a default value of 500. After adding the key, the configuration might look like this:

{
    "services": {
        "routing": {
            "apiKey": "",
            ...
            "tuning": {
                "target": {
                    ...
                    "recentDurationMilliseconds": 500,
                    ...

Storing the updated configuration

After all these changes have been done to the configuration file, it can be applied to the router using confcli.

confcli will still display error messages because the stored configuration is not valid. They will not be displayed anymore after the valid configuration has been applied.

$ confcli -i < updated_config.json
[2023-12-12 18:52:05,500] [ERROR] Missing configuration key /services/routing/translationFunctions
[2023-12-12 18:52:05,502] [ERROR] Missing configuration key /services/routing/settings/instream/dashManifestRewrite/sessionGroupNames
[2023-12-12 18:52:05,502] [ERROR] Missing configuration key /services/routing/settings/instream/hlsManifestRewrite/sessionGroupNames
[2023-12-12 18:52:05,503] [ERROR] Missing configuration key /services/routing/settings/managedSessions
[2023-12-12 18:52:05,511] [ERROR] Missing configuration key /services/routing/tuning/target/recentDurationMilliseconds

Raw configuration

The following changes have been made to the raw configuration. If the router is configured via confd and confcli, these changes will be applied by them. This section is only relevant if the router is configured via the v2/configuration API.

Simple changes

The following keys were added or removed. They will not need to be manually updated, the router will add the new keys with default values.

Removed the tuning.repeated_session_start_threshold_seconds key.
Removed the lua_paths key.
Added the tuning.target_recent_duration_milliseconds key.

EDNS proxy changes

If the router has been configured to use an EDNS server, the following has to be changed for the configuration to work.

The hosts.proxy_address key has been renamed to hosts.proxy_url and now accepts a port that is used when connecting to the proxy.

The cdns.http_port and cdns.https_port keys now configure the port that is used for connecting to the EDNS server, before they configured the port that is used for connecting to the proxy.

3 - Firewall

Firewall Configuration

For security reasons, the ESB3024 Installer does not automatically configure the local firewall to allow incoming traffic. It is the responsibility of the operations person to ensure that the system is protected from external access by placing it behind a suitable firewall solution. The following table describes the set of ports required for operation of the router.

Application	Port	Protocol	Direction	Source	Description
Prometheus Alert Manager	9093	TCP	IN	internal	Monitoring Services
Confd	5000	TCP	IN	internal	Configuration Services
Router	80	TCP	IN	public	Incoming HTTP Requests
Router	443	TCP	IN	public	Incoming HTTPS Requests
Router	5001	TCP	IN	localhost	Access to router’s REST API
Router	8000	TCP	IN	localhost	Internal monitoring port
EDNS-Proxy	8888	TCP	IN	localhost	Proxy EDNS Requests
Grafana	3000	TCP	IN	internal	Monitoring Services
Grafana-Loki	3100	TCP	IN	internal	Log monitoring daemon
Prometheus	9090	TCP	IN	internal	Monitoring Service

The “Direction” column represents the direction in which the connection is established.

IN - The connection is originated from an outside server
OUT - The connection is established from the host to an external server.

Once a connection is established through the firewall, bidirectional traffic must be allowed using the established connection.

For the “Source” column, the following terms are used.

internal - Any host or network which is allowed to monitor or operate the system.
public - Any host or subnet that can access the router. This includes any customer network that will be making routing requests.
localhost - Access can be limited to local connections only.
any - All traffic from any source or to any destination.

Additional Ports

Convoy bridge integration

The optional convoy-bridge service needs the ability to access the Convoy MariaDB service, which by default runs on port 3306 on all of the Convoy Management servers. To allow this integration to run, port 3306/tcp must be allowed from the router to the configured Convoy Management node.

4 - API Overview

A brief description of the API:s served by ESB3024 Router

ESB3024 Router provides two different types of API:s:

A content request API that is used by video clients to ask for content, normally using port 80 for HTTP and port 443 for HTTPS.
A few REST API:s used by administrators to configure and monitor the router installation, using port 5001 over HTTPS by default.

The content API won’t be described further in this document, since it’s a simple HTTP interface serving content as regular files or redirect responses.

Raw configuration – `/v2/configuration`

Used to check and update the raw configuration of ESB3024 Router. Note that this API is considered an implementation detail and is not documented further.

REQUEST Method	Content-Type	RESPONSE Result	Status Code	Content-Type
`GET`	<N/A>	Success	200 OK	`application/json`
`PUT`	`application/json`	Success	204 No Content	<N/A>
`PUT`	`application/json`	Failure	400 Bad Request	`application/json`¹

Validate Configuration – `/v2/validate_configuration`

Used to determine if a JSON payload is correctly formatted without actually applying its configuration. A successful return status does not guarantee that the applied configuration will work, it only validates the JSON structure.

REQUEST Method	Content-Type	RESPONSE Result	Status Code	Content-Type
`PUT`	`application/json`	Success	204 No Content	<N/A>
`PUT`	`application/json`	Failure	400 Bad Request	`application/json`¹

Example request

When an expected field is missing from the payload, the validation will show which one and return an appropriate error message in its payload:

$ curl -i -X PUT \
    -d '{"routing": {"log_level": 3}}' \
    -H "Content-Type: application/json" \
    https://router.example:5001/v2/validate_configuration
HTTP/1.1 400 Bad Request
Access-Control-Allow-Origin: *
Content-Length: 132
Content-Type: application/json
X-Service-Identity: router.example-5fc78d

"Configuration validation: Configuration parsing failed. \
  Exception: [json.exception.out_of_range.403] (/routing) key 'id' not found"

Selection Input – `/v1/selection_input`

Selection input API can be used to inject external key:value data into the routing engine, making the data available when making routing decisions. An arbitrary JSON structure can be pushed to the endpoint. When performing GET or DELETE requests, specific selection input values can be accessed or deleted by including a path to the request. Note that not specifying a path will select all selection input values.

One use case for selection input is to provide data on cache availability. E.g. If you send {"edge-streamer-2-online": true} to the selection input API, you can create a routing condition eq('edge-streamer-online', true) to ensure that no traffic gets routed to the streamer if it’s offline. Note that sending the same key:value data to the selection input API will overwrite the previous value.

There is a configurable limit to how many key:value items that can be injected into the router, see the tuning parameter

$ confcli services.routing.tuning.general.selectionInputItemLimit
{
    "selectionInputItemLimit": 10000
}

REQUEST Method	Content-Type	RESPONSE Result	Status Code	Content-Type
`PUT`	`application/json`	Success	204 No Content	<N/A>
`PUT`	`application/json`	Failure	400 Bad Request	`application/json`
`GET`	<N/A>	Success	200 OK	`application/json`
`DELETE`	<N/A>	Success	204 No Content	<N/A>
`DELETE`	<N/A>	Failure	404 Not Found	<N/A>

Example successful request (`PUT`)

$ curl -i -X PUT \
    -d '{"host1_bitrate": 13000, "host1_capacity": 50000}' \
    -H "Content-Type: application/json" \
    https://router.example:5001/v1/selection_input
HTTP/1.1 204 No Content
Access-Control-Allow-Origin: *
Content-Length: 0
X-Service-Identity: router.example-5fc78d

Example unsuccessful request (`PUT`)

$ curl -i -X PUT \
    -d '{"cdn-status": {"session-count": 12345, "load-percent" 98}}' \
    -H "Content-Type: application/json" \
    https://router.example:5001/v1/selection_input
HTTP/1.1 400 Bad Request
Access-Control-Allow-Origin: *
Content-Length: 169
Content-Type: application/json
X-Service-Identity: router.example-5fc78d

{
  "error": "[json.exception.parse_error.101] parse error at line 1, column 57: \
    syntax error while parsing object separator - \
    unexpected number literal; expected ':'"
}

Example successful request (`GET`)

curl -i https://router.example:5001/v1/selection_input
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Length: 129
Content-Type: application/json
X-Service-Identity: router.example-5fc78d

{
  "host1_bitrate": 13000,
  "host1_capacity": 50000
}

Example successful specific value request (`GET`)

curl -i https://router.example:5001/v1/selection_input/path/to/value
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Length: 129
Content-Type: application/json
X-Service-Identity: router.example-5fc78d

1

Example successful request (`DELETE`)

curl -i -X DELETE https://router.example:5001/v1/selection_input
HTTP/1.1 204 OK
Access-Control-Allow-Origin: *
Content-Length: 129
X-Service-Identity: router.example-5fc78d

Example successful specific value request (`DELETE`)

curl -i -X DELETE  https://router.example:5001/v1/selection_input/value/to/delete
HTTP/1.1 204 OK
Access-Control-Allow-Origin: *
Content-Length: 129
X-Service-Identity: router.example-5fc78d

Example unsuccessful request (`DELETE`)

curl -i -X DELETE  https://router.example:5001/v1/selection_input/non/existent/value
HTTP/1.1 404 Not Found
Access-Control-Allow-Origin: *
Content-Length: 129
X-Service-Identity: router.example-5fc78d

Subnets – `/v1/subnets`

An API for managing named subnets that can be used for routing and block lists. See Subnets for more details.

PUT requests inject key value pairs with the form {<subnet>: <value>}, where <subnet> is a valid CIDR string, into ACD, e.g.:

$ curl -i -X PUT \
    -d '{"255.255.255.255/24": "area1", "1.2.3.4/24": "area2"}' \
    -H "Content-Type: application/json" \
    https://router.example:5001/v1/subnets
HTTP/1.1 204 No Content
Access-Control-Allow-Origin: *
Content-Length: 0
X-Service-Identity: router.example-5fc78d

GET requests are used to fetch injected subnets, e.g.:

# Fetch all injected subnets
$ curl -i https://router.example:5001/v1/subnets
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Length: 411
Content-Type: application/json
X-Service-Identity: router.example-5fc78d

{
  "1.2.3.4/16": "area2",
  "1.2.3.4/24": "area1",
  "1.2.3.4/8": "area3",
  "255.255.255.255/16": "area2",
  "255.255.255.255/24": "area1",
  "255.255.255.255/8": "area3",
  "2a02:2e02:9bc0::/16": "area8",
  "2a02:2e02:9bc0::/32": "area7",
  "2a02:2e02:9bc0::/48": "area6",
  "2a02:2e02:9de0::/44": "combined_area",
  "2a02:2e02:ada0::/44": "combined_area",
  "5.5.0.4/8": "area5",
  "90.90.1.3/16": "area4"
}

DELETE requests are used to delete injected subnets, e.g.:

# Delete all injected subnets
$ curl -i https://router.example:5001/v1/subnets -X DELETE
HTTP/1.1 204 No Content
Access-Control-Allow-Origin: *
Content-Length: 0
X-Service-Identity: router.example-5fc78d

Both GET and DELETE requests can be specified with the paths /byKey/ and /byValue/ to filter which subnets to GET or DELETE.

# Fetch subnet with the CIDR string 1.2.3.4/8 if it exists
$ curl -i https://router.example:5001/v1/subnets/byKey/1.2.3.4/8
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Length: 26
Content-Type: application/json
X-Service-Identity: router.example-5fc78d

{
  "1.2.3.4/8": "area3"
}

# Fetch all subnets whose CIDR string begins with the IP 1.2.3.4
$ curl -i https://router.example:5001/v1/subnets/byKey/1.2.3.4
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Length: 76
Content-Type: application/json
X-Service-Identity: router.example-5fc78d

{
  "1.2.3.4/16": "area2",
  "1.2.3.4/24": "area1",
  "1.2.3.4/8": "area3"
}

# Fetch all subnets whose value equals 'area1'
$ curl -i https://router.example:5001/v1/subnets/byValue/area1
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Length: 60
Content-Type: application/json
X-Service-Identity: router.example-5fc78d

{
  "1.2.3.4/24": "area1",
  "255.255.255.255/24": "area1"
}

# Delete subnet with the CIDR string 1.2.3.4/8 if it exists
$ curl -i https://router.example:5001/v1/subnets/byKey/1.2.3.4/8
HTTP/1.1 204 No Content
Access-Control-Allow-Origin: *
Content-Length: 0
X-Service-Identity: router.example-5fc78d

# Delete all subnets whose CIDR string begins with the IP 1.2.3.4
$ curl -i https://router.example:5001/v1/subnets/byKey/1.2.3.4
HTTP/1.1 204 No Content
Access-Control-Allow-Origin: *
Content-Length: 0
X-Service-Identity: router.example-5fc78d

# Delete all subnets whose value equals 'area1'
$ curl -i https://router.example:5001/v1/subnets/byValue/area1
HTTP/1.1 204 No Content
Access-Control-Allow-Origin: *
Content-Length: 0
X-Service-Identity: router.example-5fc78d

REQUEST Method	Content-Type	RESPONSE Result	Status Code	Content-Type
`PUT`	`application/json`	Success	204 No Content	<N/A>
`PUT`	`application/json`	Failure	400 Bad Request	`application/json`
`GET`	<N/A>	Success	200 OK	`application/json`
`GET`	<N/A>	Failure	400 Bad Request	`application/json`
`DELETE`	<N/A>	Success	204 No Content	`application/json`
`DELETE`	<N/A>	Failure	400 Bad Request	`application/json`

Subrunner Resource Usage – `/v1/usage`

Used to monitor the load on subrunners, the processes performing those tasks that are possible to run in parallel.

REQUEST Method	Content-Type	RESPONSE Result	Status Code	Content-Type
`GET`	<N/A>	Success	200 OK	`application/json`

Example request

$ curl -i https://router.example:5001/v1/usage
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Length: 1234
Content-Type: application/json
X-Service-Identity: router.example-5fc78d

{
  "total_usage": {
    "content": {
      "lru": 0,
      "newest": "-",
      "oldest": "-",
      "total": 0
    },
    "sessions": 0,
    "subrunner_usage": {
      [...]
    }
  },
  "usage_per_subrunner": [
    {
      "subrunner_usage": {
        [...]
      }
    },
    [...]
  ]
}

Metrics – `/m1/v1/metrics`

An interface intended to be scraped by Prometheus. It is possible to scrape it manually to see current values, but doing so will reset some counters and cause actual Prometheus data to become faulty.

REQUEST Method	Content-Type	RESPONSE Result	Status Code	Content-Type
`GET`	<N/A>	Success	200 OK	`text/plain`

Example request

$ curl -i https://router.example:5001/m1/v1/metrics
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Length: 1234
Content-Type: text/plain
X-Service-Identity: router.example-5fc78d

# TYPE num_configuration_changes counter
num_configuration_changes 12
# TYPE num_log_errors_total counter
num_log_errors_total 0
# TYPE num_log_warnings_total counter
num_log_warnings_total{category=""} 123
# TYPE num_log_warnings_total counter
num_log_warnings_total{category="cdn"} 0
# TYPE num_log_warnings_total counter
num_log_warnings_total{category="content"} 0
# TYPE num_log_warnings_total counter
num_log_warnings_total{category="generic"} 10
# TYPE num_log_warnings_total counter
num_log_warnings_total{category="repeated_session"} 0
# TYPE num_ssl_errors_total counter
[...]

Node Visit Counters – `/v1/node_visits`

Used to gather statistics about the number of visits to each node in the routing tree. The returned value is a JSON object containing node ID names and their corresponding counter values.

REQUEST Method	Content-Type	RESPONSE Result	Status Code	Content-Type
`GET`	<N/A>	Success	200 OK	`application/json`

See Routing Rule Evaluation Metrics for more details.

Example request

$ curl -i https://router.example:5001/v1/node_visits
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Length: 73
Content-Type: application/json
X-Service-Identity: router.example-5fc78d

{
  "cache1.tv": "99900",
  "offload": "100"
  "routingtable": "100000"
}

Node Visit Graph – `/v1/node_visits_graph`

Creates a GraphML representation of the node visitation data that can be rendered into an image to make it easier to understand the data.

REQUEST Method	Content-Type	RESPONSE Result	Status Code	Content-Type
`GET`	<N/A>	Success	200 OK	`application/xml`

See Routing Rule Evaluation Metrics for more details.

Example request

> curl -i -k https://router.example:5001/v1/node_visits_graph
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Length: 731
Content-Type: application/xml
X-Service-Identity: router.example-5fc78d

<?xml version="1.0"?>
<graphml xmlns="http://graphml.graphdrawing.org/xmlns"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://graphml.graphdrawing.org/xmlns http://graphml.graphdrawing.org/xmlns/1.0/graphml.xsd">
  <key id="visits" for="node" attr.name="visits" attr.type="string" />
  <graph id="G" edgedefault="directed">
    <node id="routingtable">
      <data key="visits">100000</data>
    </node>
    <node id="cache1.tv">
      <data key="visits">99900</data>
    </node>
    <node id="offload">
      <data key="visits">100</data>
    </node>
    <edge id="e0" source="routingtable" target="cache1.tv" />
    <edge id="e1" source="routingtable" target="offload" />
  </graph>
</graphml>

Session list - `/v1/sessions`

Used to monitor the load on subrunners, the processes performing those tasks that are possible to run in parallel.

REQUEST Method	Content-Type	RESPONSE Result	Status Code	Content-Type
`GET`	<N/A>	Success	200 OK	`application/json`

Example request

$ curl -k -i https://router.example:5001/v1/sessions
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Length: 12345
Content-Type: application/json
X-Service-Identity: router.example-5fc78d

{
  "sessions": [
    {
      "age_seconds": 103,
      "cdn": "edgeware",
      "cdn_is_redirecting": false,
      "client_ip": "1.2.3.4",
      "host": "cdn.example:80",
      "id": "router.example-5fc78d-00000001",
      "idle_seconds": 103,
      "last_request_time": "2022-12-02T14:05:05Z",
      "latest_request_path": "/__cl/s:storage1/__c/v/f/0/5/v_sintel3v_f05a05f07d352e891d79863131ef4df7/__op/hls-default/__f/index.m3u8",
      "no_of_requests": 1,
      "requested_bytes": 0,
      "requests_redirected": 0,
      "requests_served": 0,
      "session_groups": [
        "all"
      ],
      "session_groups_generation": 2,
      "session_path": "/__cl/s:storage1/__c/v/f/0/5/v_sintel3v_f05a05f07d352e891d79863131ef4df7/__op/hls-default/__f/index.m3u8",
      "start_time": "2022-12-02T14:05:05Z",
      "type": "instream",
      "user_agent": "libmpv"
    },
    [...]
  ]
}

Session details - `/v1/sessions/<id: str>`

Used to get details about a specific session from the above session list. The id part of the URL corresponds to the id field in one of the returned session entries in the above response.

REQUEST Method	Content-Type	RESPONSE Result	Status Code	Content-Type
`GET`	<N/A>	Success	200 OK	`application/json`
`GET`	<N/A>	Failure	404 Not Found	`application/json`

Example request

$ curl -k -i https://router.example:5001/v1/sessions/router.example-5fc78d-00000001
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Length: 763
Content-Type: application/json
X-Service-Identity: router.example-5fc78d

{
  "age_seconds": 183,
  "cdn": "edgeware",
  "cdn_is_redirecting": false,
  "client_ip": "1.2.3.4",
  "host": "cdn.example:80",
  "id": "router.example-5fc78d-00000001",
  "idle_seconds": 183,
  "last_request_time": "2022-12-02T14:05:05Z",
  "latest_request_path": "/__cl/s:storage1/__c/v/f/0/5/v_sintel3v_f05a05f07d352e891d79863131ef4df7/__op/hls-default/__f/index.m3u8",
  "no_of_requests": 1,
  "requested_bytes": 0,
  "requests_redirected": 0,
  "requests_served": 0,
  "session_groups": [
    "all"
  ],
  "session_groups_generation": 2,
  "session_path": "/__cl/s:storage1/__c/v/f/0/5/v_sintel3v_f05a05f07d352e891d79863131ef4df7/__op/hls-default/__f/index.m3u8",
  "start_time": "2022-12-02T14:05:05Z",
  "type": "instream",
  "user_agent": "libmpv"
}

Content List - `/v1/content`

REQUEST Method	Content-Type	RESPONSE Result	Status Code	Content-Type
`GET`	<N/A>	Success	200 OK	`application/json`

Example request

$ curl -k -i https://router.example:5001/v1/content
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Length: 572
Content-Type: application/json
X-Service-Identity: router.example-5fc78d

{
  "content": [
    [
      "/__cl/s:storage1/__c/v/f/0/5/v_sintel3v_f05a05f07d352e891d79863131ef4df7/__op/hls-default/__f/index.m3u8",
      {
        "cached_count": 0,
        "content_requested": false,
        "content_set": false,
        "expiration_time": "2022-12-02T14:05:05Z",
        "key": "/__cl/s:storage1/__c/v/f/0/5/v_sintel3v_f05a05f07d352e891d79863131ef4df7/__op/hls-default/__f/index.m3u8",
        "listeners": 0,
        "manifest": "",
        "request_count": 4,
        "state": "HLS:MANIFEST-PENDING",
        "wait_count": 0
      }
    ]
  ]
}

Lua scripts – `/v1/lua/<path str>.lua`

Used to upload, retrieve and delete custom named Lua scripts on the router. Global functions in uploaded scripts automatically become available to Lua code in the configuration (which effectively may be viewed as hooks). Upload a script by PUTing a application/x-lua to the endpoint, and retrieve it by GETing the endpoint without payload.

REQUEST Method	Content-Type	RESPONSE Result	Status Code	Content-Type
`PUT`	`application/x-lua`	Success	204 No Content	<N/A>
`PUT`	`application/x-lua`	Failure	400 Bad Request	`application/json`
`GET`	<N/A>	Success	200 OK	`application/x-lua`
`GET`	<N/A>	Failure	404 Not Found	`application/json`
`DELETE`	<N/A>	Success	204 No Content	<N/A>
`DELETE`	<N/A>	Failure	400 Bad Request	`application/json`
`DELETE`	<N/A>	Failure	404 Not Found	`application/json`

Example request (`PUT`)

Save a Lua script under the name advanced_functions/f1.lua:

$ curl -i -X PUT \
    -d 'function fun1() return 1 end' \
    -H "Content-Type: application/x-lua" \
    https://router.example:5001/v1/lua/advanced_functions/f1.lua
HTTP/1.1 204 Successfully saved Lua file
Access-Control-Allow-Origin: *
Content-Length: 0
X-Service-Identity: router.example-5fc78d

Example request (`PUT`, from file)

Upload an entire Lua file under the name advanced_functions/f1.lua:

First put your code in a file.

$ cat f1.lua
function fun1()
    return 1
end

Then upload it using the --data-binary flag to preserve newlines

$ curl -i -X PUT \
    --data-binary @f1.lua \
    -H "Content-Type: application/x-lua" \
    https://router.example:5001/v1/lua/advanced_functions/f1.lua
HTTP/1.1 204 Successfully saved Lua file
Access-Control-Allow-Origin: *
Content-Length: 0
X-Service-Identity: router.example-5fc78d

Example request (`GET`)

Request the Lua script named advanced_functions/f1.lua using a GET request:

$ curl -i https://router.example:5001/v1/lua/advanced_functions/f1.lua
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Length: 28
Content-Type: application/x-lua
X-Service-Identity: router.example-5fc78d

function fun1() return 1 end

Example request (`DELETE`)

Delete the Lua script named advanced_functions/f1.lua using a DELETE request:

$ curl -i -X DELETE \
    https://router.example:5001/v1/lua/advanced_functions/f1.lua
HTTP/1.1 204 Successfully removed Lua file
Access-Control-Allow-Origin: *
Content-Length: 0
X-Service-Identity: router.example-5fc78d

List Lua scripts – `/v1/lua`

Used to list previously uploaded custom Lua scripts on the router, retrieving their respective paths and file checksums.

REQUEST Method	Content-Type	RESPONSE Result	Status Code	Content-Type
`GET`	<N/A>	Success	200 OK	`application/json`

Example request

$ curl -k -i https://router.example:5001/v1/lua
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Length: 108
Content-Type: application/json
X-Service-Identity: router.example-5fc78d

[
  {
    "file_checksum": "d41d8cd98f00b204e9800998ecf8427e",
    "path": "advanced_functions/f1.lua"
  }
]

Debug a Lua expression – `/v1/lua/debug`

Used to debug an arbitrary Lua expression on the router in a “sandbox” (with no visible side effects to the state of the router), and inspect the result.

The Lua expression in the body is evaluated inside an isolated copy of the internal Lua environment including selection input. The stdout field of the resulting JSON body is populated with a concatenation of every string provided as argument to the Lua print() function during the course of evaluation. Upon a successful evaluation, as indicated by the success flag, return.value and return.lua_type_name capture the resulting Lua value. Otherwise, if valuation was aborted (e.g. due to a Lua exception), error_msg reflects any error description arising from the Lua environment.

REQUEST Method	Content-Type	RESPONSE Result	Status Code	Content-Type
`POST`	`application/x-lua`	Success	200 OK	`application/json`

Example successful request

$ curl -i -X POST \
    -d 'fun1()' \
    -H "Content-Type: application/x-lua" \
    https://router.example:5001/v1/lua/debug
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Length: 123
Content-Type: application/json
X-Service-Identity: router.example-5fc78d

{
  "error_msg": "",
  "return": {
    "lua_type_name": "number",
    "value": 1.0
  },
  "stdout": "",
  "success": true
}

Example unsuccessful request

(attempt to invoke unknown function)

$ curl -i -X POST \
    -d 'fun5()' \
    -H "Content-Type: application/x-lua" \
    https://router.example:5001/v1/lua/debug
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Length: 123
Content-Type: application/json
X-Service-Identity: router.example-5fc78d

{
  "error_msg": "[string \"function f0() ...\"]:2: attempt to call global 'fun5' (a nil value)",
  "return": {
    "lua_type_name": "",
    "value": null
  },
  "stdout": "",
  "success": false
}

Access logging

When the configuration parameter tuning.access_log is set to true, HTTP requests are logged in the common log format (see https://en.wikipedia.org/wiki/Common_Log_Format) and tagged with the matchable field "ACCESSLOG=1" to be retrieved with journalctl:

journalctl SYSLOG_IDENTIFIER=router ACCESSLOG=1

Example output

-- Logs begin at Tue 2023-05-23 07:57:16 UTC, end at Mon 2023-05-29 07:25:59 UTC. --
May 29 07:20:00 router[52236]: ::1 - - [29/May/2023:07:20:00 +0000] "GET /vod/batman.m3u8 HTTP/1.1" 302 0 "-" "curl/7.61.1"

Some useful optional arguments to journalctl are:

journalctl SYSLOG_IDENTIFIER=router ACCESSLOG=1 [--follow] [-o json-pretty] [--since 2022-06-06] [--until 2022-06-10]
[--grep="HTTP/1.1\" 404"]

See the journalctl documentation for further reading.

Footnotes

The content type of the response is set to “application/json” but the payload is actually a regular string without JSON syntax. ↩︎ ↩︎

5 - Configuration

How to write and deploy configuration for ESB3024 Router

5.1 - WebUI Configuration

How to use the web user interface for configuration.

The web based user interface is installed as a separate component and can be used to configure many common use cases. After navigating to the UI, a login screen will be presented.

Enter your credentials and log in. In the top left corner is a menu to select what section of the configuration to change. The configuration that will be active on the router is added in the Routing Workflow view. However, basic elements such as classification rules and routing targets, etc must be added first. Hence the following main steps are required to produce a proper configuration:

Create classifiers serving as basic elements to create session groups.
Create session groups which, using the classifiers, tag requests/clients for later use in the routing logic. of the incoming traffic.
Define offload rules.
Define rules to control behavior of internal traffic.
Define backup rules to be used if the routing targets in the above step are unavailable.
Finally, create the desired routing workflow using the elements defined in the previous steps.

A simplified concrete example of the above steps could be:

Create two classifiers “smartphone” and “off-net”.
Create a session group “mobile off-net”.
Offload off-net traffic from mobile phones to a public CDN.
Route other traffic to a private CDN.
If the private CDN has an outage, use the public CDN for all traffic.

Hence, to start with, define the classifiers you will need. Those are based on information in the incoming request, optionally in combination with GeoIP databases or subnet information configured via the Subnet API. Here we show how to set up a GeoIP classifier. Note that the Director ships with a compatible snapshot of the GeoIP database, but for a production system a licensed and updated database is required.

GeoIP Classifier

Click the plus sign indicated in the picture above to create a new GeoIP classifier. You will be presented with the following view:

GeoIP Classifier Create

Here you can enter the geographical data on which to match, or check the “Inverted” check box to match anything except the entered geographical data.

The other kinds of classifiers are configured in a similar way.

After having added all the classifiers you need, it is time to create the session groups. Those are named filters that group incoming requests, typically video playback sessions in a video streaming CDN, and are defined with the help of the classifiers. For example, a session group “off-net mobile devices” could be composed of the classifiers “off-net traffic” and “mobile devices”.

Open the Session Groups view from the menu and hit the plus sign to add a new session group.

Session Groups Session Group Create

Define the new sessions groups by combining the previously created classifiers. It is often convenient to define an “All” session group that matches any incoming request.

Next go the “CDN Offload” view:

CDN Offload

Here you define conditions for CDN offload. Each row defines a rule for offloading a specified session group. The rule makes use of the Selection Input API. This is an integration API that provides a way to supply additional data for use in the routing decision. Common examples are current bitrates or availability status. The selection input variables to use must be defined in the “Selection Input Types” view in the “Administration” section of the menu:

Selection Input Types

Reach out to the solution engineers from Agile Content in order to perform this integration in the best way. If no external data is required, such that the offload rule can be based solely based on session groups, this is not necessary and the condition field can be set to “Always” or “Disabled”.

When clicking the plus sign to add a new CDN Offload rule, the following view is presented:

CDN Offload Create

The selection input rule is phrased in terms of a variable being above or below a threshold, but also a state such as “available” taking values 0 or 1 can be supported by for instance checking if “available” is below 1.

Moving on, if an incoming request is not offloaded, it will be handled by the Primary CDN section of the routing configuration.

Primary CDN

Add all hosts in your primary CDN, together with a weight. A row in this table will be selected by random weighted load balancing. If each weight is the same, each row will be selected with the same probability. Another example would be three rows with weights 100, 100 and 200 which would randomly balance 50% of the load on the last row and the remaining load on the first two rows, i.e. 25% on each of the first and second row. If a Primary CDN host is unavailable, that host will not take part in the random selection.

If all hosts are unavailable, as a final resort the routing evaluation will go to the final Backup CDN step:

Backup CDN

Here you can define what to do when all else fail. If not all requests are covered, for example with an “All” session group, then the request will fail with 403 Forbidden.

Now you have defined the basic elements and it is time to define the routing workflow. Select “Routing Workflow” from the menu, as pictured below. Here you can combine the elements previously created to achieve the desired routing behavior.

Routing Workflow

When everything seems correct, open the “Publish Routing” view from the menu:

Publish Routing

Hit “Publish All Changes” and verify that you get a successful result.

5.2 - Confd and Confcli

Using the command line tool confcli to set up routing rules

Configuration of a complex routing tree can be difficult. The command line interface tool called confcli has been developed to make it simpler. It combines building blocks, representing simple routing decisions, into complex routing trees capable of satisfying almost any routing requirements.

These blocks are translated into an ESB3024 Router configuration which is automatically sent to the router, overwriting existing routing rules, CDN list and host list.

Installation and Usage

The confcli tools are installed alongside ESB3024 Router, on the same host, and the confcli command line tool itself is made available on the host machine.

Simply type confcli in a shell on the host to see the current routing configuration:

$ confcli
{
    "services": {
        "routing": {
            "settings": {
                "trustedProxies": [],
                "contentPopularity": {
                    "algorithm": "score_based",
                    "sessionGroupNames": []
                },
                "extendedContentIdentifier": {
                    "enabled": false,
                    "includedQueryParams": []
                },
                "instream": {
                    "dashManifestRewrite": {
                        "enabled": false,
                        "sessionGroupNames": []
                    },
                    "hlsManifestRewrite": {
                        "enabled": false,
                        "sessionGroupNames": []
                    },
                    "reversedFilenameComparison": false
                },
                "usageLog": {
                    "enabled": false,
                    "logInterval": 3600000
                }
            },
            "tuning": {
                "content": {
                    "cacheSizeFullManifests": 1000,
                    "cacheSizeLightManifests": 10000,
                    "lightCacheTimeMilliseconds": 86400000,
                    "liveCacheTimeMilliseconds": 100,
                    "vodCacheTimeMilliseconds": 10000
                },
                "general": {
                    "accessLog": false,
                    "coutFlushRateMilliseconds": 1000,
                    "cpuLoadWindowSize": 10,
                    "eagerCdnSwitching": false,
                    "httpPipeliningEnable": false,
                    "logLevel": 3,
                    "maxConnectionsPerHost": 5,
                    "overloadThreshold": 32,
                    "readyThreshold": 8,
                    "redirectingCdnManifestDownloadRetries": 2,
                    "repeatedSessionStartThresholdSeconds": 30,
                    "selectionInputMetricsTimeoutSeconds": 30
                },
                "session": {
                    "idleDeactivateTimeoutMilliseconds": 20000,
                    "idleDeleteTimeoutMilliseconds": 1800000
                },
                "target": {
                    "responseTimeoutSeconds": 5,
                    "retryConnectTimeoutSeconds": 2,
                    "retryResponseTimeoutSeconds": 2,
                    "connectTimeoutSeconds": 5,
                    "maxIdleTimeSeconds": 30,
                    "requestAttempts": 3
                }
            },
            "sessionGroups": [],
            "classifiers": [],
            "hostGroups": [],
            "rules": [],
            "entrypoint": "",
            "applyConfig": true
        }
    }
}

The CLI tool can be used to modify, add and delete values by providing it with the “path” to the object to change. The path is constructed by joining the field names leading up to the value with a period between each name, e.g. the path to the entrypoint is services.routing.entrypoint since entrypoint is nested under the routing object, which in turn is under the services root object. Lists use an index number in place of a field name, where 0 indicates the very first element in the list, 1 the second element and so on.

If the list contains objects which have a field with the name name, the index number can be replaced by the unique name of the object of interest.

Tab completion is supported by confcli. Pressing tab once will complete as far as possible, and pressing tab twice will list all available alternatives at the path constructed so far.

Display the values at a specific path:

$ confcli services.routing.hostGroups
{
    "hostGroups": [
        {
            "name": "internal",
            "type": "redirecting",
            "httpPort": 80,
            "httpsPort": 443,
            "hosts": [
                {
                    "name": "rr1",
                    "hostname": "rr1.example.com",
                    "ipv6_address": ""
                }
            ]
        },
        {
            "name": "external",
            "type": "host",
            "httpPort": 80,
            "httpsPort": 443,
            "hosts": [
                {
                    "name": "offload-streamer1",
                    "hostname": "streamer1.example.com",
                    "ipv6_address": ""
                },
                {
                    "name": "offload-streamer2",
                    "hostname": "streamer2.example.com",
                    "ipv6_address": ""
                }
            ]
        }
    ]
}

Display the values in a specific list index:

$ confcli services.routing.hostGroups.1
{
    "1": {
        "name": "external",
        "type": "host",
        "httpPort": 80,
        "httpsPort": 443,
        "hosts": [
            {
                "name": "offload-streamer1",
                "hostname": "streamer1.example.com",
                "ipv6_address": ""
            },
            {
                "name": "offload-streamer2",
                "hostname": "streamer2.example.com",
                "ipv6_address": ""
            }
        ]
    }
}

Display the values in a specific list index using the object’s name:

$ confcli services.routing.hostGroups.1.hosts.offload-streamer2
{
    "offload-streamer2": {
        "name": "offload-streamer2",
        "hostname": "streamer2.example.com",
        "ipv6_address": ""
    }
}

Modify a single value:

confcli services.routing.hostGroups.1.hosts.offload-streamer2.hostname new-streamer.example.com
services.routing.hostGroups.1.hosts.offload-streamer2.hostname = 'new-streamer.example.com'

Delete an entry:

$ confcli services.routing.sessionGroups.Apple.classifiers.
{
    "classifiers": [
        "Apple",
        ""
    ]
}

$ confcli services.routing.sessionGroups.Apple.classifiers.1 -d
http://localhost:5000/config/__active/services/routing/sessionGroups/Apple/classifiers/1 reset to default/deleted

$ confcli services.routing.sessionGroups.Apple.classifiers.
{
    "classifiers": [
        "Apple"
    ]
}

Adding new values in objects and lists is done using a wizard by invoking confcli with a path and the -w argument. This will be shown extensively in the examples further down in this document rather than here.

If you have a JSON file with a previously generated confcli configuration output it can be applied to a system by typing confcli -i <file path>.

CDNs and Hosts

Configuration using confcli has no real concept of CDNs, instead it has groups of hosts that share some common settings such as HTTP(S) port and whether they return a redirection URL, serve content directly or perform a DNS lookup. Of these three variants, the two former share the same parameters, while the DNS variant is slightly different.

Each host belongs to a host group and may itself be an entire CDN using a single public hostname or a single streamer server, all depending on the needs of the user.

Host Health

When creating a host in the confd configuration, you have the option to define a list of health check functions. Each health check function must return true for a host to be selected. This means that the host will only be considered available if all the defined health check functions evaluate to true. If any of the health check functions return false, the host will be considered unavailable and will not be selected for routing. All health check functions are detailed in the section Built-in Lua functions.

$ confcli services.routing.hostGroups -w
Running wizard for resource 'hostGroups'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

hostGroups : [
  hostGroup can be one of
    1: dns
    2: host
    3: redirecting
  Choose element index or name: redirecting
  Adding a 'redirecting' element
    hostGroup : {
      name (default: ): edgeware
      type (default: redirecting): ⏎
      httpPort (default: 80): ⏎
      httpsPort (default: 443): ⏎
      hosts : [
        host : {
          name (default: ): rr1
          hostname (default: ): convoy-rr1.example.com
          ipv6_address (default: ): ⏎
          healthChecks : [
            healthCheck (default: always()): health_check()
            Add another 'healthCheck' element to array 'healthChecks'? [y/N]: n
          ]
        }
        Add another 'host' element to array 'hosts'? [y/N]: y
        host : {
          name (default: ): rr2
          hostname (default: ): convoy-rr2.example.com
          ipv6_address (default: ): ⏎
          healthChecks : [
            healthCheck (default: always()): ⏎
            Add another 'healthCheck' element to array 'healthChecks'? [y/N]: n
          ]
        }
        Add another 'host' element to array 'hosts'? [y/N]: ⏎
      ]
    }
  Add another 'hostGroup' element to array 'hostGroups'? [y/N]: ⏎
]
Generated config:
{
  "hostGroups": [
    {
      "name": "edgeware",
      "type": "redirecting",
      "httpPort": 80,
      "httpsPort": 443,
      "hosts": [
        {
          "name": "rr1",
          "hostname": "convoy-rr1.example.com",
          "ipv6_address": "",
          "healthChecks": [
            "health_check()"
          ]
        },
        {
          "name": "rr2",
          "hostname": "convoy-rr2.example.com",
          "ipv6_address": "",
          "healthChecks": [
            "always()"
          ]
        }
      ]
    }
  ]
}
Merge and apply the config? [y/n]: y

$ confcli services.routing.hostGroups -w
Running wizard for resource 'hostGroups'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

hostGroups : [
  hostGroup can be one of
    1: dns
    2: host
    3: redirecting
  Choose element index or name: dns
  Adding a 'dns' element
    hostGroup : {
      name (default: ): external-dns
      type (default: dns): ⏎
      hosts : [
        host : {
          name (default: ): dns-host
          hostname (default: ): dns.example.com
          ipv6_address (default: ): ⏎
          healthChecks : [
            healthCheck (default: always()): ⏎
            Add another 'healthCheck' element to array 'healthChecks'? [y/N]: n
          ]
        }
        Add another 'host' element to array 'hosts'? [y/N]: ⏎
      ]
    }
  Add another 'hostGroup' element to array 'hostGroups'? [y/N]: ⏎
]
Generated config:
{
  "hostGroups": [
    {
      "name": "external-dns",
      "type": "dns",
      "hosts": [
        {
          "name": "dns-host",
          "hostname": "dns.example.com",
          "ipv6_address": "",
          "healthChecks": [
            "always()"
          ]
        }
      ]
    }
  ]
}
Merge and apply the config? [y/n]: y

Rule Blocks

The routing configuration using confcli is done using a combination of logical building blocks, or rules. Each block evaluates the incoming request in some way and sends it on to one or more sub-blocks. If the block is of the host type described above, the client is sent to that host and the evaluation is done.

Existing blocks

Currently supported blocks are:

allow: Incoming requests, for which a given rule function matches, are immediately sent to the provided onMatch target.
consistentHashing: Splits incoming requests randomly between preferred hosts, determined by the proprietary consistent hashing algorithm. The amount of hosts to split between is controlled by the spreadFactor.
contentPopularity: Splits incoming requests into two sub-blocks depending on how popular the requested content is.
deny: Incoming requests, for which a given rule function matches, are immediately denied, and all non-matching requests are sent to the onMiss target.
firstMatch: Incoming requests are matched by an ordered series of rules, where the request will be handled by the first rule for which the condition evaluates to true.
random: Splits incoming requests randomly and equally between a list of target sub-blocks. Useful for simple load balancing.
split: Splits incoming requests between two sub-blocks depending on how the request is evaluated by a provided function. Can be used for sending clients to different hosts depending on e.g. geographical location or client hardware type.
weighted: Randomly splits incoming requests between a list of target sub-blocks, weighted according to each target’s associated weight rule. A higher weight means a higher portion of requests will be routed to a sub-block. Rules can be used to decide whether or not to pick a target.
rawGroup: Contains a raw ESB3024 Router configuration routing tree node, to be inserted as is in the generated configuration. This is only meant to be used in the rare cases when it’s impossible to construct the required routing behavior in any other way.
rawHost: A host reference for use as endpoints in rawGroup trees.

$ confcli services.routing.rules -w
Running wizard for resource 'rules'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

rules : [
  rule can be one of
    1: allow
    2: consistentHashing
    3: contentPopularity
    4: deny
    5: firstMatch
    6: random
    7: rawGroup
    8: rawHost
    9: split
    10: weighted
  Choose element index or name: allow
  Adding a 'allow' element
    rule : {
      name (default: ): allow
      type (default: allow): ⏎
      condition (default: ): customFunction()
      onMatch (default: ): rr1
    }
  Add another 'rule' element to array 'rules'? [y/N]: ⏎
]
Generated config:
{
  "rules": [
    {
      "name": "content",
      "type": "contentPopularity",
      "condition": "customFunction()",
      "onMatch": "rr1"
    }
  ]
}
Merge and apply the config? [y/n]: y

$ confcli services.routing.rules -w
Running wizard for resource 'rules'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

rules : [
  rule can be one of
    1: allow
    2: consistentHashing
    3: contentPopularity
    4: deny
    5: firstMatch
    6: random
    7: rawGroup
    8: rawHost
    9: split
    10: weighted
  Choose element index or name: consistentHashing
  Adding a 'consistentHashing' element
    rule : {
      name (default: ): consistentHashingRule
      type (default: consistentHashing): 
      spreadFactor (default: 1): 2
      hashAlgorithm (default: MD5):
      targets : [
        target : {
          target (default: ): rr1
          enabled (default: True): 
        }
        Add another 'target' element to array 'targets'? [y/N]: y
        target : {
          target (default: ): rr2
          enabled (default: True): 
        }
        Add another 'target' element to array 'targets'? [y/N]: y
        target : {
          target (default: ): rr3
          enabled (default: True): 
        }
        Add another 'target' element to array 'targets'? [y/N]: n
      ]
    }
  Add another 'rule' element to array 'rules'? [y/N]: n
]
Generated config:
{
  "rules": [
    {
      "name": "consistentHashingRule",
      "type": "consistentHashing",
      "spreadFactor": 2,
      "hashAlgorithm": "MD5",
      "targets": [
        {
          "target": "rr1",
          "enabled": true
        },
        {
          "target": "rr2",
          "enabled": true
        },
        {
          "target": "rr3",
          "enabled": true
        }
      ]
    }
  ]
}
Merge and apply the config? [y/n]: y

$ confcli services.routing.rules -w
Running wizard for resource 'rules'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

rules : [
  rule can be one of
    1: allow
    2: consistentHashing
    3: contentPopularity
    4: deny
    5: firstMatch
    6: random
    7: rawGroup
    8: rawHost
    9: split
    10: weighted
  Choose element index or name: contentPopularity
  Adding a 'contentPopularity' element
    rule : {
      name (default: ): content
      type (default: contentPopularity): ⏎
      contentPopularityCutoff (default: 10): 20
      onPopular (default: ): rr1
      onUnpopular (default: ): rr2
    }
  Add another 'rule' element to array 'rules'? [y/N]: ⏎
]
Generated config:
{
  "rules": [
    {
      "name": "content",
      "type": "contentPopularity",
      "contentPopularityCutoff": 20.0,
      "onPopular": "rr1",
      "onUnpopular": "rr2"
    }
  ]
}
Merge and apply the config? [y/n]: y

$ confcli services.routing.rules -w
Running wizard for resource 'rules'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

rules : [
  rule can be one of
    1: allow
    2: consistentHashing
    3: contentPopularity
    4: deny
    5: firstMatch
    6: random
    7: rawGroup
    8: rawHost
    9: split
    10: weighted
  Choose element index or name: deny
  Adding a 'deny' element
    rule : {
      name (default: ): deny
      type (default: deny): ⏎
      condition (default: ): customFunction()
      onMiss (default: ): rr1
    }
  Add another 'rule' element to array 'rules'? [y/N]: ⏎
]
Generated config:
{
  "rules": [
    {
      "name": "content",
      "type": "contentPopularity",
      "condition": "customFunction()",
      "onMiss": "rr1"
    }
  ]
}
Merge and apply the config? [y/n]: y

$ confcli services.routing.rules -w
Running wizard for resource 'rules'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

rules : [
  rule can be one of
    1: allow
    2: consistentHashing
    3: contentPopularity
    4: deny
    5: firstMatch
    6: random
    7: rawGroup
    8: rawHost
    9: split
    10: weighted
  Choose element index or name: firstMatch
  Adding a 'firstMatch' element
    rule : {
      name (default: ): firstMatch
      type (default: firstMatch): ⏎
      targets : [
        target : {
          onMatch (default: ): rr1
          rule (default: ): customFunction()
        }
        Add another 'target' element to array 'targets'? [y/N]: y
        target : {
          onMatch (default: ): rr2
          rule (default: ): otherCustomFunction()
        }
        Add another 'target' element to array 'targets'? [y/N]: n
      ]
    }
  Add another 'rule' element to array 'rules'? [y/N]: n
]
Generated config:
{
  "rules": [
    {
      "name": "firstMatch",
      "type": "firstMatch",
      "targets": [
        {
          "onMatch": "rr1",
          "condition": "customFunction()"
        },
        {
          "onMatch": "rr2",
          "condition": "otherCustomFunction()"
        }
      ]
    }
  ]
}
Merge and apply the config? [y/n]: y

$ confcli services.routing.rules -w
Running wizard for resource 'rules'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

rules : [
  rule can be one of
    1: allow
    2: consistentHashing
    3: contentPopularity
    4: deny
    5: firstMatch
    6: random
    7: rawGroup
    8: rawHost
    9: split
    10: weighted
  Choose element index or name: random
  Adding a 'random' element
    rule : {
      name (default: ): random
      type (default: random): ⏎
      targets : [
        target (default: ): rr1
        Add another 'target' element to array 'targets'? [y/N]: y
        target (default: ): rr2
        Add another 'target' element to array 'targets'? [y/N]: ⏎
      ]
    }
  Add another 'rule' element to array 'rules'? [y/N]: ⏎
]
Generated config:
{
  "rules": [
    {
      "name": "random",
      "type": "random",
      "targets": [
        "rr1",
        "rr2"
      ]
    }
  ]
}
Merge and apply the config? [y/n]: y

$ confcli services.routing.rules -w
Running wizard for resource 'rules'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

rules : [
  rule can be one of
    1: allow
    2: consistentHashing
    3: contentPopularity
    4: deny
    5: firstMatch
    6: random
    7: rawGroup
    8: rawHost
    9: split
    10: weighted
  Choose element index or name: split
  Adding a 'split' element
    rule : {
      name (default: ): split
      type (default: split): ⏎
      condition (default: ): custom_function()
      onMatch (default: ): rr2
      onMiss (default: ): rr1
    }
  Add another 'rule' element to array 'rules'? [y/N]: ⏎
]
Generated config:
{
  "rules": [
    {
      "name": "split",
      "type": "split",
      "condition": "custom_function()",
      "onMatch": "rr2",
      "onMiss": "rr1"
    }
  ]
}
Merge and apply the config? [y/n]: y

$ confcli services.routing.rules. -w
Running wizard for resource 'rules'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

rules : [
  rule can be one of
    1: allow
    2: consistentHashing
    3: contentPopularity
    4: deny
    5: firstMatch
    6: random
    7: rawGroup
    8: rawHost
    9: split
    10: weighted
  Choose element index or name: weighted
  Adding a 'weighted' element
    rule : {
      name (default: ): weight
      type (default: weighted): ⏎
      targets : [
        target : {
          target (default: ): rr1
          weight (default: 100): ⏎
          condition (default: always()): always()
        }
        Add another 'target' element to array 'targets'? [y/N]: y
        target : {
          target (default: ): rr2
          weight (default: 100): si('rr2-input-weight')
          condition (default: always()): gt('rr2-bandwidth', 1000000)
        }
        Add another 'target' element to array 'targets'? [y/N]: y
        target : {
          target (default: ): rr2
          weight (default: 100): custom_func()
          condition (default: always()): always()
        }
        Add another 'target' element to array 'targets'? [y/N]: ⏎
      ]
    }
  Add another 'rule' element to array 'rules'? [y/N]: ⏎
]
Generated config:
{
  "rules": [
    {
      "name": "weight",
      "type": "weighted",
      "targets": [
        {
          "target": "rr1",
          "weight": "100",
          "condition": "always()"
        },
        {
          "target": "rr2",
          "weight": "si('rr2-input-weight')",
          "condition": "gt('rr2-bandwith', 1000000)"
        },
        {
          "target": "rr2",
          "weight": "custom_func()",
          "condition": "always()"
        }
      ]
    }
  ]
}
Merge and apply the config? [y/n]: y

>> First add a raw host block that refers to a regular host

$ confcli services.routing.rules. -w
Running wizard for resource 'rules'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

rules : [
  rule can be one of
    1: allow
    2: consistentHashing
    3: contentPopularity
    4: deny
    5: firstMatch
    6: random
    7: rawGroup
    8: rawHost
    9: split
    10: weighted
  Choose element index or name: rawHost
  Adding a 'rawHost' element
    rule : {
      name (default: ): raw-host
      type (default: rawHost): ⏎
      hostId (default: ): rr1
    }
  Add another 'rule' element to array 'rules'? [y/N]: ⏎
]
Generated config:
{
  "rules": [
    {
      "name": "raw-host",
      "type": "rawHost",
      "hostId": "rr1"
    }
  ]
}
Merge and apply the config? [y/n]: y

>> And then add a rule using the host node

$ confcli services.routing.rules. -w
Running wizard for resource 'rules'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

rules : [
  rule can be one of
    1: allow
    2: consistentHashing
    3: contentPopularity
    4: deny
    5: firstMatch
    6: random
    7: rawGroup
    8: rawHost
    9: split
    10: weighted
  Choose element index or name: rawGroup
  Adding a 'rawGroup' element
    rule : {
      name (default: ): raw-node
      type (default: rawGroup): ⏎
      memberOrder (default: sequential): ⏎
      members : [
        member : {
          target (default: ): raw-host
          weightFunction (default: ): return 1
        }
        Add another 'member' element to array 'members'? [y/N]: ⏎
      ]
    }
  Add another 'rule' element to array 'rules'? [y/N]: ⏎
]
Generated config:
{
  "rules": [
    {
      "name": "raw-node",
      "type": "rawGroup",
      "memberOrder": "sequential",
      "members": [
        {
          "target": "raw-host",
          "weightFunction": "return 1"
        }
      ]
    }
  ]
}
Merge and apply the config? [y/n]: y

Rule Language

Some blocks, such as the split and firstMatch types, have a rule field that contains a small function in a very simple programming language. This field is used to filter any incoming client requests in order to determine how to rule block should react.

In the case of a split block, the rule is evaluated and if it is true the client is sent to the onMatch part of the block, otherwise it is sent to the onMiss part for further evaluation.

In the case of a firstMatch block, the rule for each target will be evaluated top to bottom in order until either a rule evaluates to true or the list is exhausted. If a rule evaluates to true, the client will be sent to the onMatch part of the block, otherwise the next target in the list will be tried. If all targets have been exhausted, then the entire rule evaluation will fail, and the routing tree will be restarted with the firstMatch block effectively removed.

Example of Boolean Functions

Let’s say we have an ESB3024 Router set up with a session group that matches Apple devices (named “Apple”). To route all Apple devices to a specific streamer one would simply create a split block with the following rule:

in_session_group('Apple')

In order to make more complex rules it’s possible to combine several checks like this in the same rule. Let’s extend the hypothetical ESB3024 Router above with a configured subnet with all IP addresses in Europe (named “Europe”). To make a rule that accepts any clients using an Apple device and living outside of Europe, but only as long as the reported load on the streamer (as indicated by the selection input variable “europe_load_mbps”) is less than 1000 megabits per second one could make an offload block with the following rule (without linebreaks):

in_session_group('Apple')
    and not in_subnet('Europe')
    and lt('europe_load_mbps', 1000)

In this example in_session_group('Apple') will be true if the client belongs to the session group named ‘Apple’. The function call in_subnet('Europe') is true if the client’s IP belongs to the subnet named ‘Europe’, but the word not in front of it reverses the value so the entire section ends up being false if the client is in Europe. Finally lt('europe_load_mbps', 1000) is true if there is a selection input variable named “europe_load_mbps” and its value is less than 1000.

Since the three parts are conjoined with the and keyword they must all be true for the entire rule to match. If the keyword or had been used instead it would have been enough for any of the parts to be true for the rule to match.

Example of Numeric Functions

A hypothetical CDN has two streamers with different capacity; Host_1 has roughly twice the capacity of Host_2. A simple random load balancing would put undue stress on the second host since it will receive as much traffic as the more capable Host_1.

This can be solved by using a weighted random distribution rule block with suitable rules for the two hosts:

{
    "targets": [
        {
            "target": "Host_1",
            "condition": "always()",
            "weight": "100"
        }
        {
            "target": "Host_2",
            "condition": "always()",
            "weight": "50"
        },
    ]
}

resulting in Host_1 receiving twice as many requests as Host_2 as its weight function is double that of Host_2.

If the CDN is capable of reporting the free capacity of the hosts, for example by writing to a selection input variable for each host, it’s easy to write a more intelligent load balancing rule by making the weights correspond to the amount of capacity left on each host:

{
    "targets": [
        {
            "target": "Host_1",
            "condition": "always()",
            "weight": "si('free_capacity_host_1')"
        }
        {
            "target": "Host_2",
            "condition": "always()",
            "weight": "si('free_capacity_host_2')"
        },
    ]
}

It is also possible to write custom Lua functions that return suitable weights, perhaps taking the host as an argument:

{
    "targets": [
        {
            "target": "Host_1",
            "condition": "always()",
            "weight": "intelligent_weight_function('Host_1')"
        }
        {
            "target": "Host_2",
            "condition": "always()",
            "weight": "intelligent_weight_function('Host_1')"
        },
    ]
}

These different weight rules can of course be combined in the same rule block, with one target having a hard coded number, another using a dynamically updated selection input variable and yet another having a custom-built function.

Due to limitations in the random number generator used to distribute requests, it’s better to use somewhat large values, around 100–1000 or so, than to use small values near 0.

Built-in Functions

The following built-in functions are available when writing rules:

in_session_group(str name): True if session belongs to session group <name>
in_all_session_groups(str sg_name, ...): True if session belongs to all specified session groups
in_any_session_group(str sg_name, ...): True if session belongs to any specified session group
in_subnet(str subnet_name): True if client IP belongs to the named subnet
gt(str si_var, number value): True if selection_inputs[si_var] > value
gt(str si_var1, str si_var2): True if selection_inputs[si_var1] > selection_inputs[si_var2]
ge(str si_var, number value): True if selection_inputs[si_var] >= value
ge(str si_var1, str si_var2): True if selection_inputs[si_var1] >= selection_inputs[si_var2]
lt(str si_var, number value): True if selection_inputs[si_var] < value
lt(str si_var1, str si_var2): True if selection_inputs[si_var1] < selection_inputs[si_var2]
le(str si_var, number value): True if selection_inputs[si_var] <= value
le(str si_var1, str si_var2): True if selection_inputs[si_var1] <= selection_inputs[si_var2]
eq(str si_var, number value): True if selection_inputs[si_var] == value
eq(str si_var1, str si_var2): True if selection_inputs[si_var1] == selection_inputs[si_var2]
neq(str si_var, number value): True if selection_inputs[si_var] != value
neq(str si_var1, str si_var2): True if selection_inputs[si_var1] != selection_inputs[si_var2]
si(str si_var): Returns the value of selection_inputs[si_var] if it is defined and non-negative, otherwise it returns 0.
always(): Returns true, useful when creating weighted rule blocks.
never(): Returns false, opposite of always().

These functions, as well as custom functions written in Lua and uploaded to the ESB3024 Router, can be combined to make suitably precise rules.

Combining Multiple Boolean Functions

In order to make the rule language easy to work with, it is fairly restricted and simple. One restriction is that it’s only possible to chain multiple function results together using either and or or, but not a combination of both conjunctions.

Statements joined with and or or keywords are evaluated one by one, starting with the left-most statement and moving right. As soon as the end result of the entire expression is certain, the evaluation ends. This means that evaluation ends with the first false statement for and expressions since a single false component means the entire expression must also be false. It also means that evaluation ends with the first true statement for or expressions since only one component must be true for the entire statement to be true as well. This is known as short-circuit or lazy evaluation.

Custom Functions

It is possible to write extremely complex Lua functions that take many parameters or calculations into consideration when evaluating an incoming client request. By writing such functions and making sure that they return only non-negative integer values and uploading them to the router they can be used from the rule language. Simply call them like any of the built-in functions listed above, using strings and numbers as arguments if necessary, and their result will be used to determine the routing path to use.

Formal Syntax

The full syntax of the language can be described in just a few lines of BNF grammar:

<rule>               := <weight_rule> | <match_rule> | <value_rule>
<weight_rule>        := "if" <compound_predicate> "then" <weight> "else" <weight>
<match_rule>         := <compound_predicate>
<value_rule>         := <weight>
<compound_predicate> := <logical_predicate> |
                        <logical_predicate> ["and" <logical_predicate> ...] |
                        <logical_predicate> ["or" <logical_predicate> ...] |
<logical_predicate>  := ["not"] <predicate>
<predicate>          := <function_name> "(" ")" |
                        <function_name> "(" <argument> ["," <argument> ...] ")"
<function_name>      := <letter> [<function_name_tail> ...]
<function_name_tail> := empty | <letter> | <digit> | "_"
<argument>           := <string> | <number>
<weight>             := integer | <predicate>
<number>             := float | integer
<string>             := "'" [<letter> | <digit> | <symbol> ...] "'"

Building a Routing Configuration

This example sets up an entire routing configuration for a system with a ESB3008 Request Router, two streamers and the Apple devices outside of Europe example used earlier in this document. Any clients not matching the criteria will be sent to an offload CDN with two streamers in a simple uniformly randomized load balancing setup.

Set up Session Group

First make a classifier and a session group that uses it:

$ confcli services.routing.classifiers -w
Running wizard for resource 'classifiers'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

classifiers : [
  classifier can be one of
    1: anonymousIp
    2: asnIds
    3: contentUrlPath
    4: contentUrlQueryParameters
    5: geoip
    6: hostName
    7: ipranges
    8: random
    9: regexMatcher
    10: stringMatcher
    11: subnet
    12: userAgent
  Choose element index or name: userAgent
  Adding a 'userAgent' element
    classifier : {
      name (default: ): Apple
      type (default: userAgent): ⏎
      inverted (default: False): ⏎
      patternType (default: stringMatch): ⏎
      pattern (default: ): *apple*
    }
  Add another 'classifier' element to array 'classifiers'? [y/N]: ⏎
]
Generated config:
{
  "classifiers": [
    {
      "name": "Apple",
      "type": "userAgent",
      "inverted": false,
      "patternType": "stringMatch",
      "pattern": "*apple*"
    }
  ]
}
Merge and apply the config? [y/n]: y

$ confcli services.routing.sessionGroups -w
Running wizard for resource 'sessionGroups'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

sessionGroups : [
  sessionGroup : {
    name (default: ): Apple
    classifiers : [
      classifier (default: ): Apple
      Add another 'classifier' element to array 'classifiers'? [y/N]: ⏎
    ]
  }
  Add another 'sessionGroup' element to array 'sessionGroups'? [y/N]: ⏎
]
Generated config:
{
  "sessionGroups": [
    {
      "name": "Apple",
      "classifiers": [
        "Apple"
      ]
    }
  ]
}
Merge and apply the config? [y/n]: y

Set up Hosts

Create two host groups and add a Request Router to the first and two streamers to the second, which will be used for offload:

$ confcli services.routing.hostGroups -w
Running wizard for resource 'hostGroups'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

hostGroups : [
  hostGroup can be one of
    1: dns
    2: host
    3: redirecting
  Choose element index or name: redirecting
  Adding a 'redirecting' element
    hostGroup : {
      name (default: ): internal
      type (default: redirecting): ⏎
      httpPort (default: 80): ⏎
      httpsPort (default: 443): ⏎
      hosts : [
        host : {
          name (default: ): rr1
          hostname (default: ): rr1.example.com
          ipv6_address (default: ): ⏎
        }
        Add another 'host' element to array 'hosts'? [y/N]: ⏎
      ]
    }
  Add another 'hostGroup' element to array 'hostGroups'? [y/N]: y
  hostGroup can be one of
    1: dns
    2: host
    3: redirecting
  Choose element index or name: host
  Adding a 'host' element
    hostGroup : {
      name (default: ): external
      type (default: host): ⏎
      httpPort (default: 80): ⏎
      httpsPort (default: 443): ⏎
      hosts : [
        host : {
          name (default: ): offload-streamer1
          hostname (default: ): streamer1.example.com
          ipv6_address (default: ): ⏎
        }
        Add another 'host' element to array 'hosts'? [y/N]: y
        host : {
          name (default: ): offload-streamer2
          hostname (default: ): streamer2.example.com
          ipv6_address (default: ): ⏎
        }
        Add another 'host' element to array 'hosts'? [y/N]: ⏎
      ]
    }
  Add another 'hostGroup' element to array 'hostGroups'? [y/N]: ⏎
]
Generated config:
{
  "hostGroups": [
    {
      "name": "internal",
      "type": "redirecting",
      "httpPort": 80,
      "httpsPort": 443,
      "hosts": [
        {
          "name": "rr1",
          "hostname": "rr1.example.com",
          "ipv6_address": ""
        }
      ]
    },
    {
      "name": "external",
      "type": "host",
      "httpPort": 80,
      "httpsPort": 443,
      "hosts": [
        {
          "name": "offload-streamer1",
          "hostname": "streamer1.example.com",
          "ipv6_address": ""
        },
        {
          "name": "offload-streamer2",
          "hostname": "streamer2.example.com",
          "ipv6_address": ""
        }
      ]
    }
  ]
}
Merge and apply the config? [y/n]: y

Create Load Balancing and Offload Block

Add both offload streamers as targets in a randomgroup block:

$ confcli services.routing.rules -w
Running wizard for resource 'rules'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

rules : [
  rule can be one of
    1: allow
    2: consistentHashing
    3: contentPopularity
    4: deny
    5: firstMatch
    6: random
    7: rawGroup
    8: rawHost
    9: split
    10: weighted
  Choose element index or name: random
  Adding a 'random' element
    rule : {
      name (default: ): balancer
      type (default: random): ⏎
      targets : [
        target (default: ): offload-streamer1
        Add another 'target' element to array 'targets'? [y/N]: y
        target (default: ): offload-streamer2
        Add another 'target' element to array 'targets'? [y/N]: ⏎
      ]
    }
  Add another 'rule' element to array 'rules'? [y/N]: ⏎
]
Generated config:
{
  "rules": [
    {
      "name": "balancer",
      "type": "random",
      "targets": [
        "offload-streamer1",
        "offload-streamer2"
      ]
    }
  ]
}
Merge and apply the config? [y/n]: y

Then create a split block with the request router and the load balanced CDN as targets:

$ confcli services.routing.rules -w
Running wizard for resource 'rules'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

rules : [
  rule can be one of
    1: allow
    2: consistentHashing
    3: contentPopularity
    4: deny
    5: firstMatch
    6: random
    7: rawGroup
    8: rawHost
    9: split
    10: weighted
  Choose element index or name: split
  Adding a 'split' element
    rule : {
      name (default: ): offload
      type (default: split): ⏎
      rule (default: ): in_session_group('Apple') and not in_subnet('Europe') and lt('europe_load_mbps', 1000)
      onMatch (default: ): rr1
      onMiss (default: ): balancer
    }
  Add another 'rule' element to array 'rules'? [y/N]: ⏎
]
Generated config:
{
  "rules": [
    {
      "name": "offload",
      "type": "split",
      "condition": "in_session_group('Apple') and not in_subnet('Europe') and lt('europe_load_mbps', 1000)",
      "onMatch": "rr1",
      "onMiss": "balancer"
    }
  ]
}
Merge and apply the config? [y/n]: y

The last step required is to set the entrypoint of the routing tree so the router knows where to start evaluating:

$ confcli services.routing.entrypoint offload
services.routing.entrypoint = 'offload'

Evaluate

Now that all the rules have been set up properly and the router has been reconfigured. The translated configuration can be read from the router’s configuration API:

$ curl -k https://router-host:5001/v2/configuration  2> /dev/null | jq .routing
{
  "id": "offload",
  "member_order": "sequential",
  "members": [
    {
      "host_id": "rr1",
      "id": "offload.rr1",
      "weight_function": "return ((in_session_group('Apple') ~= 0) and
                          (in_subnet('Europe') == 0) and
                          (lt('europe_load_mbps', 1000) ~= 0) and 1) or 0 "
    },
    {
      "id": "offload.balancer",
      "member_order": "weighted",
      "members": [
        {
          "host_id": "offload-streamer1",
          "id": "offload.balancer.offload-streamer1",
          "weight_function": "return 100"
        },
        {
          "host_id": "offload-streamer2",
          "id": "offload.balancer.offload-streamer2",
          "weight_function": "return 100"
        }
      ],
      "weight_function": "return 1"
    }
  ],
  "weight_function": "return 100"
}

Note that the configuration language code has been translated into its Lua equivalent.

5.3 - Session Groups and Classification

How to classify clients into session groups and use them in routing

ESB3024 Router provides a flexible classification engine, allowing the assignment of clients into session groups that can then be used to base routing decisions on.

Session Classification

In order to perform routing it is necessary to classify incoming sessions according to the relevant parameters. This is done through session groups and their associated classifiers.

There are different ways of classifying a request:

Strings with wildcards: Simple case-insensitive string pattern with support for adding asterisks (’*’) in order to match any value at that point in the pattern.
String with regular expressions: A complex string matching pattern capable of matching more complicated strings than the simple wildcard matching type.

Valid string matching sources are content_url_path, content_url_query_params, hostname and user_agent, examples of which will be shown below.

GeoIP: Based on the geographic location of the client, supporting wildcard matching. Geographic location data is provided by MaxMind. The possible values to match with are any combinations of:
- Continent
- Country
- Cities
- ASN
Anonymous IP: Classifies clients using an anonymous IP. Database of anonymous IPs is provided by MaxMind.
IP range: Based on whether a client’s IP belongs to any of the listed IP ranges or not.
Subnet: Tests if a client’s IP belongs to a named subnet, see Subnets for more details.
ASN ID list: Checks to see if a client’s IP belongs to any of the specified ASN IDs.
Random: Randomly classifies clients according to a given probability. The classifier is deterministic, meaning that a session will always get the same classification, even if evaluated multiple times.

A session group may have more than one classifier. If it does, all the classifiers must match the incoming client request for it to belong to the session group. It is also possible for a request to belong to multiple session groups, or to none.

To send certain clients to a specific host you first need to create a suitable classifier using confcli in wizard mode. The wizard will guide you through the process of creating a new entry, asking you what value to input for each field and helping you by telling you what inputs are allowed for restricted fields such as the string comparison source mentioned above:

$ confcli services.routing.classifiers -w
Running wizard for resource 'classifiers'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

classifiers : [
  classifier can be one of
    1: anonymousIp
    2: asnIds
    3: contentUrlPath
    4: contentUrlQueryParameters
    5: geoip
    6: hostName
    7: ipranges
    8: random
    9: regexMatcher
    10: stringMatcher
    11: subnet
    12: userAgent
  Choose element index or name: geoip
  Adding a 'geoip' element
    classifier : {
      name (default: ): sweden_matcher
      type (default: geoip): ⏎
      inverted (default: False): ⏎
      continent (default: ): ⏎
      country (default: ): sweden
      cities : [
        city (default: ): ⏎
        Add another 'city' element to array 'cities'? [y/N]: ⏎
      ]
      asn (default: ): ⏎
    }
  Add another 'classifier' element to array 'classifiers'? [y/N]: ⏎
]
Generated config:
{
  "classifiers": [
    {
      "name": "sweden_matcher",
      "type": "geoip",
      "inverted": false,
      "continent": "",
      "country": "sweden",
      "cities": [
        ""
      ],
      "asn": ""
    }
  ]
}
Merge and apply the config? [y/n]: y

$ confcli services.routing.classifiers -w
Running wizard for resource 'classifiers'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

classifiers : [
  classifier can be one of
    1: anonymousIp
    2: asnIds
    3: contentUrlPath
    4: contentUrlQueryParameters
    5: geoip
    6: hostName
    7: ipranges
    8: random
    9: regexMatcher
    10: stringMatcher
    11: subnet
    12: userAgent
  Choose element index or name: ipranges
  Adding a 'ipranges' element
    classifier : {
      name (default: ): company_matcher
      type (default: ipranges): ⏎
      inverted (default: False): ⏎
      ipranges : [
        iprange (default: ): 90.128.0.0/12
        Add another 'iprange' element to array 'ipranges'? [y/N]: ⏎
      ]
    }
  Add another 'classifier' element to array 'classifiers'? [y/N]: ⏎
]
Generated config:
{
  "classifiers": [
    {
      "name": "company_matcher",
      "type": "ipranges",
      "inverted": false,
      "ipranges": [
        "90.128.0.0/12"
      ]
    }
  ]
}
Merge and apply the config? [y/n]: y

$ confcli services.routing.classifiers -w
Running wizard for resource 'classifiers'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

classifiers : [
  classifier can be one of
    1: anonymousIp
    2: asnIds
    3: contentUrlPath
    4: contentUrlQueryParameters
    5: geoip
    6: hostName
    7: ipranges
    8: random
    9: regexMatcher
    10: stringMatcher
    11: subnet
    12: userAgent
  Choose element index or name: stringMatcher
  Adding a 'stringMatcher' element
    classifier : {
      name (default: ): apple_matcher
      type (default: stringMatcher): ⏎
      inverted (default: False): ⏎
      source (default: content_url_path): user_agent
      pattern (default: ): *apple*
    }
  Add another 'classifier' element to array 'classifiers'? [y/N]: ⏎
]
Generated config:
{
  "classifiers": [
    {
      "name": "apple_matcher",
      "type": "stringMatcher",
      "inverted": false,
      "source": "user_agent",
      "pattern": "*apple*"
    }
  ]
}
Merge and apply the config? [y/n]: y

$ confcli services.routing.classifiers -w
Running wizard for resource 'classifiers'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

classifiers : [
  classifier can be one of
    1: anonymousIp
    2: asnIds
    3: contentUrlPath
    4: contentUrlQueryParameters
    5: geoip
    6: hostName
    7: ipranges
    8: random
    9: regexMatcher
    10: stringMatcher
    11: subnet
    12: userAgent
  Choose element index or name: regexMatcher
  Adding a 'regexMatcher' element
    classifier : {
      name (default: ): content_matcher
      type (default: regexMatcher): ⏎
      inverted (default: False): ⏎
      source (default: content_url_path): ⏎
      pattern (default: ): .*/(live|news_channel)/.*m3u8
    }
  Add another 'classifier' element to array 'classifiers'? [y/N]: ⏎
]
Generated config:
{
  "classifiers": [
    {
      "name": "content_matcher",
      "type": "regexMatcher",
      "inverted": false,
      "source": "content_url_path",
      "pattern": ".*/(live|news_channel)/.*m3u8"
    }
  ]
}
Merge and apply the config? [y/n]: y

$ confcli services.routing.classifiers -w
Running wizard for resource 'classifiers'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

classifiers : [
  classifier can be one of
    1: anonymousIp
    2: asnIds
    3: contentUrlPath
    4: contentUrlQueryParameters
    5: geoip
    6: hostName
    7: ipranges
    8: random
    9: regexMatcher
    10: stringMatcher
    11: subnet
    12: userAgent
  Choose element index or name: subnet
  Adding a 'subnet' element
    classifier : {
      name (default: ): company_matcher
      type (default: subnet): ⏎
      inverted (default: False): ⏎
      pattern (default: ): company
    }
  Add another 'classifier' element to array 'classifiers'? [y/N]: ⏎
]
Generated config:
{
  "classifiers": [
    {
      "name": "company_matcher",
      "type": "subnet",
      "inverted": false,
      "pattern": "company"
    }
  ]
}
Merge and apply the config? [y/n]: y

$ confcli services.routing.classifiers -w
Running wizard for resource 'classifiers'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

classifiers : [
  classifier can be one of
    1: anonymousIp
    2: asnIds
    3: contentUrlPath
    4: contentUrlQueryParameters
    5: geoip
    6: hostName
    7: ipranges
    8: random
    9: regexMatcher
    10: stringMatcher
    11: subnet
    12: userAgent
  Choose element index or name: hostName
  Adding a 'hostName' element
    classifier : {
      name (default: ): host_name_classifier
      type (default: hostName): ⏎
      inverted (default: False): ⏎
      patternType (default: stringMatch): ⏎
      pattern (default: ): *live.example*
    }
  Add another 'classifier' element to array 'classifiers'? [y/N]: n
]
Generated config:
{
  "classifiers": [
    {
      "name": "host_name_classifier",
      "type": "hostName",
      "inverted": false,
      "patternType": "stringMatch",
      "pattern": "*live.example*"
    }
  ]
}
Merge and apply the config? [y/n]: y

$ confcli services.routing.classifiers -w
Running wizard for resource 'classifiers'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

classifiers : [
  classifier can be one of
    1: anonymousIp
    2: asnIds
    3: contentUrlPath
    4: contentUrlQueryParameters
    5: geoip
    6: hostName
    7: ipranges
    8: random
    9: regexMatcher
    10: stringMatcher
    11: subnet
    12: userAgent
  Choose element index or name: contentUrlPath
  Adding a 'contentUrlPath' element
    classifier : {
      name (default: ): vod_matcher
      type (default: contentUrlPath): ⏎
      inverted (default: False): ⏎
      patternType (default: stringMatch): ⏎
      pattern (default: ): *vod*
    }
  Add another 'classifier' element to array 'classifiers'? [y/N]: n
]
Generated config:
{
  "classifiers": [
    {
      "name": "vod_matcher",
      "type": "contentUrlPath",
      "inverted": false,
      "patternType": "stringMatch",
      "pattern": "*vod*"
    }
  ]
}
Merge and apply the config? [y/n]: y

$ confcli services.routing.classifiers -w
Running wizard for resource 'classifiers'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

classifiers : [
  classifier can be one of
    1: anonymousIp
    2: asnIds
    3: contentUrlPath
    4: contentUrlQueryParameters
    5: geoip
    6: hostName
    7: ipranges
    8: random
    9: regexMatcher
    10: stringMatcher
    11: subnet
    12: userAgent
  Choose element index or name: contentUrlQueryParameters
  Adding a 'contentUrlQueryParameters' element
    classifier : {
      name (default: ): bitrate_matcher
      type (default: contentUrlQueryParameters): ⏎
      inverted (default: False): ⏎
      patternType (default: stringMatch): regex
      pattern (default: ): .*bitrate=100000.*
    }
  Add another 'classifier' element to array 'classifiers'? [y/N]: n
]
Generated config:
{
  "classifiers": [
    {
      "name": "bitrate_matcher",
      "type": "contentUrlQueryParameters",
      "inverted": false,
      "patternType": "regex",
      "pattern": ".*bitrate=100000.*"
    }
  ]
}
Merge and apply the config? [y/n]: y

$ confcli services.routing.classifiers -w
Running wizard for resource 'classifiers'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

classifiers : [
  classifier can be one of
    1: anonymousIp
    2: asnIds
    3: contentUrlPath
    4: contentUrlQueryParameters
    5: geoip
    6: hostName
    7: ipranges
    8: random
    9: regexMatcher
    10: stringMatcher
    11: subnet
    12: userAgent
  Choose element index or name: userAgent
  Adding a 'userAgent' element
    classifier : {
      name (default: ): iphone_matcher
      type (default: userAgent): ⏎
      inverted (default: False): ⏎
      patternType (default: stringMatch): regex
      pattern (default: ): i(P|p)hone
    }
  Add another 'classifier' element to array 'classifiers'? [y/N]: n
]
Generated config:
{
  "classifiers": [
    {
      "name": "iphone_matcher",
      "type": "userAgent",
      "inverted": false,
      "patternType": "regex",
      "pattern": "i(P|p)hone"
    }
  ]
}
Merge and apply the config? [y/n]: y

$ confcli services.routing.classifiers -w
Running wizard for resource 'classifiers'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

classifiers : [
  classifier can be one of
    1: anonymousIp
    2: asnIds
    3: contentUrlPath
    4: contentUrlQueryParameters
    5: geoip
    6: hostName
    7: ipranges
    8: random
    9: regexMatcher
    10: stringMatcher
    11: subnet
    12: userAgent
  Choose element index or name: asnIds
  Adding a 'asnIds' element
    classifier : {
      name (default: ): asn_matcher
      type (default: asnIds): ⏎
      inverted (default: False): ⏎
      asnIds <The list of ASN IDs to accept. (default: [])>: [
        asnId: 1
        Add another 'asnId' element to array 'asnIds'? [y/N]: y
        asnId: 2
        Add another 'asnId' element to array 'asnIds'? [y/N]: y
        asnId: 3
        Add another 'asnId' element to array 'asnIds'? [y/N]: ⏎
      ]
    }
  Add another 'classifier' element to array 'classifiers'? [y/N]: ⏎
]
Generated config:
{
  "classifiers": [
    {
      "name": "asn_matcher",
      "type": "asnIds",
      "inverted": false,
      "asnIds": [
        1,
        2,
        3
      ]
    }
  ]
}
Merge and apply the config? [y/n]: y

$ confcli services.routing.classifiers -w
Running wizard for resource 'classifiers'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

classifiers : [
  classifier can be one of
    1: anonymousIp
    2: asnIds
    3: contentUrlPath
    4: contentUrlQueryParameters
    5: geoip
    6: hostName
    7: ipranges
    8: random
    9: regexMatcher
    10: stringMatcher
    11: subnet
    12: userAgent
  Choose element index or name: random
  Adding a 'random' element
    classifier <A classifier randomly applying to clients based on the provided probability. (default: OrderedDict())>: {
      name (default: ): random_matcher
      type (default: random):
      probability (default: 0.5): 0.7
    }
  Add another 'classifier' element to array 'classifiers'? [y/N]: n
]
Generated config:
{
  "classifiers": [
    {
      "name": "random_matcher",
      "type": "random",
      "probability": 0.7
    }
  ]
}
Merge and apply the config? [y/n]: y

$ confcli services.routing.classifiers -w
Running wizard for resource 'classifiers'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

classifiers : [
  classifier can be one of
    1: anonymousIp
    2: asnIds
    3: contentUrlPath
    4: contentUrlQueryParameters
    5: geoip
    6: hostName
    7: ipranges
    8: random
    9: regexMatcher
    10: stringMatcher
    11: subnet
    12: userAgent
  Choose element index or name: anonymousIp
  Adding a 'anonymousIp' element
    classifier : {
      name (default: ): anon_ip_matcher
      type (default: anonymousIp):
      inverted (default: False):
    }
  Add another 'classifier' element to array 'classifiers'? [y/N]: n
]
Generated config:
{
  "classifiers": [
    {
      "name": "anon_ip_matcher",
      "type": "anonymousIp",
      "inverted": false
    }
  ]
}
Merge and apply the config? [y/n]: y

These classifiers can now be used to construct session groups and properly classify clients. Using the examples above, let’s create a session group classifying clients from Sweden using an Apple device:

$ confcli services.routing.sessionGroups -w
Running wizard for resource 'sessionGroups'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

sessionGroups : [
  sessionGroup : {
    name (default: ): inSwedenUsingAppleDevice
    classifiers : [
      classifier (default: ): sweden_matcher
      Add another 'classifier' element to array 'classifiers'? [y/N]: y
      classifier (default: ): apple_matcher
      Add another 'classifier' element to array 'classifiers'? [y/N]: ⏎
    ]
  }
  Add another 'sessionGroup' element to array 'sessionGroups'? [y/N]: ⏎
]
Generated config:
{
  "sessionGroups": [
    {
      "name": "inSwedenUsingAppleDevice",
      "classifiers": [
        "sweden_matcher",
        "apple_matcher"
      ]
    }
  ]
}
Merge and apply the config? [y/n]: y

Clients classified by the sweden_matcher and apple_matcher classifiers will now be put in the session group inSwedenUsingAppleDevice. Using session groups in routing will be demonstrated later in this document.

Advanced Classification

The above example will simply apply all classifiers in the list, and as long as they all evaluate to true for a session, that session will be tagged with the session group. For situations where this isn’t enough, classifiers can instead be combined using simple logic statements to form complex rules.

A first simple example can be a session group that accepts any viewers in either ASN 1, 2 or 3 (corresponding to the classifier asn_matcher or living in Sweden. This can be done by creating a session group, and adding the following logic statement:

'sweden_matcher' OR 'asn_matcher'

A slightly more advanced case is where a session group should only contain sessions neither in any of the three ASNs nor in Sweden. This is done by negating the previous example:

NOT ('sweden_matcher' OR 'asn_matcher')

A single classifier can also be negated, rather than the whole statement, for example to accept any Swedish viewers except those in the three ASNs:

'sweden_matcher' AND NOT 'asn_matcher'

Arbitrarily complex statements can be created using classifier names, parentheses, and the keywords AND, OR and NOT.

For example a session group accepting any Swedish viewers except those in the Stockholm region unless they are also Apple users:

'sweden_matcher' AND (NOT 'stockholm_matcher' OR 'apple_matcher')

Note that the classifier names must be enclosed in single quotes when using this syntax.

Applying this kind of complex classifier using confcli is no more difficult than adding a single classifier at a time:

$ confcli services.routing.sessionGroups. -w
Running wizard for resource 'sessionGroups'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

sessionGroups : [
  sessionGroup : {
    name (default: ): complex_group
    classifiers : [
      classifier (default: ): 'sweden_matcher' AND (NOT 'stockholm_matcher' OR 'apple_matcher')
      Add another 'classifier' element to array 'classifiers'? [y/N]: ⏎
    ]
  }
  Add another 'sessionGroup' element to array 'sessionGroups'? [y/N]: ⏎
]
Generated config:
{
  "sessionGroups": [
    {
      "name": "complex_group",
      "classifiers": [
        "'sweden_matcher' AND (NOT 'stockholm_matcher' OR 'apple_matcher')"
      ]
    }
  ]
}
Merge and apply the config? [y/n]: y

5.4 - Advanced features

Detailed descriptions and examples of advanced features within ESB3024

5.4.1 - Content popularity

How to tune content popularity parameters and use it in routing

ESB3024 Router allows routing decisions based on content popularity. All incoming content requests are tracked to continuously update a content popularity ranking list. The popularity ranking algorithm is designed to let popular content quickly rise to the top while unpopular content decays and sinks towards the bottom.

Routing

A content popularity based routing rule can be created by running

$ confcli services.routing.rules -w
Running wizard for resource 'rules'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

rules : [
  rule can be one of
    1: allow
    2: consistentHashing
    3: contentPopularity
    4: deny
    5: firstMatch
    6: random
    7: rawGroup
    8: rawHost
    9: split
    10: weighted
  Choose element index or name: contentPopularity
  Adding a 'contentPopularity' element
    rule : {
      name (default: ): content_popularity_rule
      type (default: contentPopularity):
      contentPopularityCutoff (default: 10): 5
      onPopular (default: ): edge-streamer
      onUnpopular (default: ): offload
    }
  Add another 'rule' element to array 'rules'? [y/N]: n
]
Generated config:
{
  "rules": [
    {
      "name": "content_popularity_rule",
      "type": "contentPopularity",
      "contentPopularityCutoff": 5.0,
      "onPopular": "edge-streamer",
      "onUnpopular": "offload"
    }
  ]
}
Merge and apply the config? [y/n]: y

This rule will route requests for top 5 most popular content to edge-streamer and all other requests to offload.

Some configuration settings attributed to content popularity are available:

$ confcli services.routing.settings.contentPopularity
{
    "contentPopularity": {
        "enabled": true,
        "algorithm": "score_based",
        "sessionGroupNames": []
    }
}

enabled: Whether or not to track content popularity. When enabled is set to false, content popularity will not be tracked. Note that routing on content popularity is possible even if enabled is false and content popularity has been tracked previously.
algorithm: Choice of content popularity tracking algorithm. There are two possible choices: score_based or time_based (detailed below).
sessionGroupNames: Names of the session groups for which content popularity should be tracked. Note that content popularity is tracked globally, not per session group.

Algorithm tuning

The behaviour of each content popularity tracking algorithm can be tuned using the raw JSON API.

All configuration parameters for content popularity reside in the settings object of the configuration, an example of which can be seen below:

{
  "settings": {
    "content_popularity": {
      "algorithm": "scored_based",
      "session_group_names": ["vod_only"],
      "score_based:": {
        "requests_between_popularity_decay": 1000,
        "popularity_list_max_size": 100000,
        "popularity_prediction_factor": 2.5,
        "popularity_decay_fraction": 0.2
      },
      "time_based": {
        "intervals_per_hour": 10
      }
    }
  }
}

The field algorithm dictates which content popularity tracking algorithm to use, can either be score_based or time_based.

The field session_group_names defines the sessions for which content popularity should be tracked. In the example above, session belonging to the vod_only session group will be tracked for content popularity. If left empty, content popularity will be tracked for all sessions.

The remaining configuration parameters are algorithm specific.

Score based algorithm

The field popularity_list_max_size defines the maximum amount of unique contents to track for popularity. This can be used to limit memory growth. A single entry in the popularity ranking list will at most consume 180 bytes of memory. E.g. using "popularity_list_max_size": 1000 would consume at most 180⋅1,000 = 180,000 B = 0.18 MB. If the content popularity list is full, a request to unique content would replace the least popular content.

Setting a very high max size will not impact performance, it will only consume more memory.

The field requests_between_popularity_decay defines the number of requests between each popularity decay update, an integral component of this feature.

The fields popularity_prediction_factor and popularity_decay_fraction tune the behaviour of the content popularity ranking algorithm, explained further below.

Decay update

To allow for popular content to quickly rise in popularity and unpopular content to sink, a dynamic popularity ranking algorithm is used. The goal of the algorithm is to track content popularity in real time, allowing routing decisions based on the requested content’s popularity. The algorithm is applied every decay update.

The algorithm uses current trending content to predict content popularity. The field popularity_prediction_factor regulates how much the algorithm should rely on predicted popularity. A high prediction factor allows rising content to quickly rise to high popularity but can also cause unpopular content with a sudden burst of requests to wrongfully rise to the top. A low prediction factor can cause stagnation in the popularity ranking, not allowing new popular content to rise to the top.

Unpopular content decays in popularity, the magnitude of which is regulated by popularity_decay_fraction. A high value will aggressively decay content popularity every decay update while a low value will bloat the ranking, causing stagnation. Once content decays to a trivially low popularity score, it is pruned from the content popularity list.

When configuring these tuning parameters, the most crucial data to consider is the size of your asset catalog, i.e. the number of unique contents you offer. The recommended values, obtained through testing, are presented in the table below. Note that the field popularity_prediction_factor is the principal factor in controlling the algorithm’s behaviour.

Catalog size n	`popularity_prediction_factor`	`popularity_decay_fraction`
n < 1000	2.2	0.2
1000 < n < 5000	2.3	0.2
5000 < n < 10000	2.5	0.2
n > 10000	2.6	0.2

Time based algorithm

The time based algorithm only requires the configuration parameter intervals_per_hour. E.g., the value "intervals_per_hour": 10 would give 10 six minute intervals per hour. During each interval, all unique content requests has an associated counter, increasing by one for each incoming request. After an hour, all intervals have been cycled through. The counters in the first interval will be reset and all incoming content requests will increase the counters in the first interval again. This cycle continues forever.

When determining a single content’s popularity, the sum of each content’s counter in all intervals is used to determine a popularity ranking.

5.4.2 - Consistent Hashing

Details and configuration considerations for using consistent hashing based routing

Consistent hashing based routing is a feature that can be used to distribute requests to a set of hosts in a cache friendly manner. By using Agile Content’s consistent distributed hash algorithm, the amount of cache redistribution is minimized within a set of hosts. Requests for a content will always be routed to the same set of hosts, the amount of which is configured by the spread factor, allowing high cache usage. When adding or removing hosts, the algorithm minimizes cache redistribution.

Say you have the host group [s1, s2, s3, s4, s5] and have configured spreadFactor = 3. A request for a content asset1 would then be routed to the same three hosts with one of them being selected randomly for each request. Requests for a different content asset2 would also be routed to one of three different hosts, most likely a different combination of hosts than requests for content asset1.

Example routing results with spreadFactor = 3:

Request for asset1 → route to one of [s1, s3, s4].
Request for asset2 → route to one of [s2, s4, s5].
Request for asset3 → route to one of [s1, s2, s5].

Since consistent hashing based routing ensures that requests for a specific content always get routed to the same set of hosts, the risk of cache misses are lowered on the hosts since they will be served the same content requests over and over again.

Note that the maximum value of spreadFactor is 64. Consequently, the highest amount of hosts you can use in a consistentHashing rule block is 64.

Three different hashing algorithms are available: MD5, SDBM and Murmur. The algorithm is chosen during configuration.

Configuration

Configuring consistent hashing based routing is easily done using confcli. Let’s configure the example described above:

confcli services.routing.rules -w
Running wizard for resource 'rules'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

rules : [
  rule can be one of
    1: allow
    2: consistentHashing
    3: contentPopularity
    4: deny
    5: firstMatch
    6: random
    7: rawGroup
    8: rawHost
    9: split
    10: weighted
  Choose element index or name: consistentHashing
  Adding a 'consistentHashing' element
    rule : {
      name (default: ): consistentHashingRule 
      type (default: consistentHashing): 
      spreadFactor (default: 1): 3
      hashAlgorithm (default: MD5):
      targets : [
        target : {
          target (default: ): s1
          enabled (default: True): 
        }
        Add another 'target' element to array 'targets'? [y/N]: y
        target : {
          target (default: ): s2
          enabled (default: True): 
        }
        Add another 'target' element to array 'targets'? [y/N]: y
        target : {
          target (default: ): s3
          enabled (default: True): 
        }
        Add another 'target' element to array 'targets'? [y/N]: y
        target : {
          target (default: ): s4
          enabled (default: True): 
        }
        Add another 'target' element to array 'targets'? [y/N]: y
        target : {
          target (default: ): s5
          enabled (default: True): 
        }
        Add another 'target' element to array 'targets'? [y/N]: n
      ]
    }
  Add another 'rule' element to array 'rules'? [y/N]: n
]
Generated config:
{
  "rules": [
    {
      "name": "consistentHashingRule",
      "type": "consistentHashing",
      "spreadFactor": 3,
      "hashAlgorithm": "MD5",
      "targets": [
        {
          "target": "s1",
          "enabled": true
        },
        {
          "target": "s2",
          "enabled": true
        },
        {
          "target": "s3",
          "enabled": true
        },
        {
          "target": "s4",
          "enabled": true
        },
        {
          "target": "s5",
          "enabled": true
        }
      ]
    }
  ]
}

Adding hosts

Adding a host to the list will give an additional target for the consistent hashing algorithm to route requests to. This will shift content distribution onto the new host.

confcli services.routing.rules.consistentHashingRule.targets -w
Running wizard for resource 'targets'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

targets : [
  target : {
    target (default: ): s6
    enabled (default: True): 
  }
  Add another 'target' element to array 'targets'? [y/N]: n
]
Generated config:
{
  "targets": [
    {
      "target": "s6",
      "enabled": true
    }
  ]
}
Merge and apply the config? [y/n]: y

Removing hosts

There is one very important caveat of using a consistent hashing rule block. As long as you don’t modify the list of hosts, the consistent hashing algorithm will keep routing requests to the same hosts. However, if you remove a host from the block in any position except the last, the consistent hashing algorithm’s behaviour will change and the algorithm cannot maintain a minimum amount of cache redistribution.

If you’re in a situation where you have to remove a host from the routing targets but want to keep the same consistent hashing behaviour, e.g. during very high load, you’ll have to toggle that target’s enabled field to false. E.g., disabling requests to s2 can be accomplished by:

$ confcli services.routing.rules.consistentHashingRule.targets.1.enabled false
services.routing.rules.consistentHashingRule.targets.1.enabled = False
$ confcli services.routing.rules.consistentHashingRule.targets.1
{
    "1": {
        "target": "s2",
        "enabled": false
    }
}

If you modify the list order or remove hosts, it is highly recommended to do so during moments where a higher rate of cache misses are acceptable.

5.4.3 - Security token verification

Only allow requests that contain a correct security token

The security token verification feature allows for ESB3024 Router to only process requests that contain a correct security token. The token is generated by the client, for example in the portal, using an algorithm that it shares with the router. The router verifies the token and rejects the request if the token is incorrect.

It is beyond the scope of this document to describe how the token is generated, that is described in the Security Tokens application note that is installed with the ESB3024 Router’s extra documentation.

Setting up a routing rule

The token verification is performed by calling the verify_security_token() function from a routing rule. The function returns 1 if the token is correct, otherwise it returns 0. It should typically be called from the first routing rule, to make requests with bad tokens fail as early as possible.

The confcli example assumes that the router already has rules configured, with an entry point named select_cdn. Token verification is enabled by inserting an “allow” rule first in the rule list.

confcli services.routing.rules -w
Running wizard for resource 'rules'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

rules : [
  rule can be one of
    1: allow
    2: consistentHashing
    3: contentPopularity
    4: deny
    5: firstMatch
    6: random
    7: rawGroup
    8: rawHost
    9: split
    10: weighted
  Choose element index or name: allow
  Adding a 'allow' element
    rule : {
      name (default: ): token_verification
      type (default: allow):
      condition (default: always()): verify_security_token()
      onMatch (default: ): select_cdn
    }
  Add another 'rule' element to array 'rules'? [y/N]: n
]
Generated config:
{
  "rules": [
    {
      "name": "token_verification",
      "type": "allow",
      "condition": "verify_security_token()",
      "onMatch": "select_cdn"
    }
  ]
}
Merge and apply the config? [y/n]: y

$ confcli services.routing.entrypoint token_verification
services.routing.entrypoint = 'token_verification'

"routing": {
  "id": "token_verification",
  "member_order": "sequential",
  "members": [
    {
      "id": "token_verification.0.select_cdn",
      "member_order": "weighted",
      "members": [
        ...
      ],
      "weight_function": "return verify_security_token() ~= 0"
    },
    {
      "id": "token_verification.1.rejected",
      "member_order": "sequential",
      "members": [],
      "weight_function": "return 1"
    }
  ],
  "weight_function": "return 100"
},

Configuring security token options

The secret parameter is not part of the router request, but needs to be configured separately in the router. That can be done with the host-config tool that is installed with the router.

Besides configuring the secret, host-config can also configure floating sessions and a URL prefix. Floating sessions are sessions that are not tied to a specific IP address. When that is enabled, the token verification will not take the IP address into account when verifying the token.

The security token verification is configured per host, where a host is the name of the host that the request was sent to. This makes it possible for a router to support multiple customer accounts, each with their own secret. If no configuration is found for a host, a configuration with the name default is used.

host-config supports three commands: print, set and delete.

Print

The print command prints the current configuration for a host. The following parameters are supported:

host-config print [-n <host-name>]

By default it prints the configuration for all hosts, but if the optional -n flag is given it will print the configuration for a single host.

Set

The set command sets the configuration for a host. The configuration is given as command line parameters. The following parameters are supported:

host-config set
    -n <host-name>
    [-f floating]
    [-p url-prefix]
    [-r <secret-to-remove>]
    [-s <secret-to-add>]

-n <host-name> - The name of the host to configure.
-f floating - A boolean option that specifies if floating sessions are accepted. The parameter accepts the values true and false.
-p url-prefix - A URL prefix that is used for identifying requests that come from a certain account. This is not used when verifying tokens.
-r <secret-to-remove> - A secret that should be removed from the list of secrets.
-s <secret-to-add> - A secret that should be added to the list of secrets.

For example, to set the secret “secret-1” and enable floating sessions for the default host, the following command can be used:

host-config set -n default -s secret-1 -f true

The set command only touches the configuration options that are mentioned on the command line, so the following command line will add a second secret to the default host without changing the floating session setting:

host-config set -n default -s secret-2

It is possible to set multiple secrets per host. This is useful when updating a secret, then both the old and the new secret can be valid during the transition period. After the transition period the old secret can be removed by typing:

host-config set -n default -r secret-1

Delete

The delete command deletes the configuration for a host. It supports the following parameters:

host-config delete -n <host-name>

For example, to delete the configuration for example.com, the following command can be used:

host-config delete -n example.com

Global options

host-config also has a few global options. They are:

-k <security-key> - The security key that is used when communicating with the router. This is normally retrieved automatically.
-h - Print a help message and exit.
-r <router> - The router to connect to. This default to localhost, but can be changed to connect to a remote router.
-v - Verbose output, can be given multiple times.

Debugging security token verification

The security token verification only logs messages when the log level is set to 4 or higher. Then it will only log some errors. It is possible to enable more verbose logging using the security-token-config that is installed together with the router.

When verbose logging is enabled, the router will log information about the token verification, including the configured token secrets, so it needs to be used with care.

The logged lines are prefixed with verify_security_token.

The security-token-config tool supports the commands print and set.

Print

The print command prints the current configuration. If nothing is configured it will not print anything.

Set

The set command sets the configuration. The following parameters are supported:

security-token-config set
    [-d <enabled>]

-d <enabled> - A boolean option that specifies if debug logging should be enabled or not. The parameter accepts the values true and false.

5.4.4 - Subnets API

How to match clients into named subnets and use them in routing

ESB3024 Router provides utilities to quickly match clients into subnets. Any combination of IPv4 and IPv6 addresses can be used. To begin, a JSON file is needed, defining all subnets, e.g:

{
  "255.255.255.255/24": "area1",
  "255.255.255.255/16": "area2",
  "255.255.255.255/8": "area3",
  "90.90.1.3/16": "area4",
  "5.5.0.4/8": "area5",
  "2a02:2e02:9bc0::/48": "area6",
  "2a02:2e02:9bc0::/32": "area7",
  "2a02:2e02:9bc0::/16": "area8",
  "2a02:2e02:9de0::/44": "combined_area",
  "2a02:2e02:ada0::/44": "combined_area"
}

and PUT it to the endpoint :5001/v1/subnets or :5001/v2/subnets, the API version doesn’t matter for subnets:

curl -k -T subnets.json -H "Content-Type: application/json" https://router-host:5001/v1/subnets

Note that it is possible for several subnet CIDR strings to share the same label, effectively grouping them together.

The router provides the built-in function in_subnet(subnet_name) that can to make routing decisions based on a client’s subnet. For more details, see Built-in Lua functions. To configure a rule that only allows clients in the area1 subnet, run the command

$ confcli services.routing.rules -w
Running wizard for resource 'rules'

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

rules : [
  rule can be one of
    1: allow
    2: consistentHashing
    3: contentPopularity
    4: deny
    5: firstMatch
    6: random
    7: rawGroup
    8: rawHost
    9: split
    10: weighted
  Choose element index or name: allow
  Adding a 'allow' element
    rule : {
      name (default: ): only_allow_area1
      type (default: allow):
      condition (default: always()): in_subnet('area1')
      onMatch (default: ): example-host
    }
  Add another 'rule' element to array 'rules'? [y/N]: n
]
Generated config:
{
  "rules": [
    {
      "name": "only_allow_area1",
      "type": "allow",
      "condition": "in_subnet('area1')",
      "onMatch": "example-host"
    }
  ]
}
Merge and apply the config? [y/n]: y

Invalid IP-addresses will be omitted during subnet list construction accompanied by a message in the log displaying the invalid IP address.

5.4.5 - Lua Features

Detailed descriptions and examples of Lua features offered by ESB3024 Router.

5.4.5.1 - Built-in Lua Functions

All built-in Lua functions available for routing.

This section details all built-in Lua functions provided by the router.

Logging functions

The router provides Lua logging functionality that is convenient when creating custom Lua functions. A prefix can be added to the log message which is useful to differentiate log messages from different lua files. At the top of the Lua source file, add the line

local log = log.add_prefix("my_lua_file")

to prepend all log messages with "my_lua_file".

The logging functions support formatting and common log levels:

log.critical('A log message with number %d', 1.5)
log.error('A log message with string %s', 'a string')
log.warning('A log message with integer %i', 1)
log.info('A log message with a local number variable %d', some_local_number)
log.debug('A log message with a local string variable %s', some_local_string)
log.trace('A log message with a local integer variable %i', some_local_integer)
log.message('A log message')

Many of the router’s built-in Lua functions use the logging functions.

Logging functions

The router provides Lua logging functionality that is convenient when creating custom Lua functions. A prepend can be added to the log message which is useful to differentiate log messages from different lua files. At the top of the file, add the line

local log = log.add_prefix("my_lua_file")

to prepend all log messages with "my_lua_file".

The logging functions support formatting and common log levels:

log.critical('A log message with number %d', 1.5)
log.error('A log message with string %s', 'a string')
log.warning('A log message with integer %i', 1)
log.info('A log message with a local number variable %d', some_local_number)
log.debug('A log message with a local string variable %s', some_local_string)
log.trace('A log message with a local integer variable %i', some_local_integer)
log.message('A log message')

Many of the router’s built in Lua functions use the logging functions.

Predictive load balancing functions

Predictive load balancing is a tool that can be used to avoid overloading hosts with traffic. Consider the case where a popular event starts at a certain time, let’s say 12 PM. A spike in traffic will be routed to the hosts that are streaming the content at 12 PM, most of them starting at low bitrates. A host might have sufficient bandwidth left to take on more clients but when the recently connected clients start ramping up in video quality and increase their bitrate, the host can quickly become overloaded, possibly dropping incoming requests or going offline. Predictive load balancing solves this issue by considering how many times a host recently been redirected to.

Four functions for predictive load balancing are provided by the router that can be used when constructing conditions/weight functions: host_bitrate() , host_bitrate_custom(), host_has_bw() and host_has_bw_custom(). All require data to be supplied to the selection input API and apply only to leaf nodes in the routing tree. In order for predictive load balancing to work properly the data must be updated at regular intervals. The data needs to be supplied by the target system.

These functions are suitable to used as host health checks. To configure host health checks, see configuring CDNs and hosts.

Note that host_bitrate() and host_has_bw() rely on data supplied by metrics agents, detailed in Cache hardware metrics: monitoring and routing.

host_bitrate_custom() and host_has_bw_custom() rely on manually supplied selection input data, detailed in selection input API. The bitrate unit depends on the data submitted to the selection input API.

Example metrics

The data supplied to the selection input API by the metrics agents uses the following structure:

{
  "streamer-1": {
    "hardware_metrics": {
      "/": {
        "free": 1741596278784,
        "total": 1758357934080,
        "used": 16761655296,
        "used_percent": 0.9532561585516977
      },
      "cpu_load1": 0.02,
      "cpu_load15": 0.12,
      "cpu_load5": 0.02,
      "mem_available": 4895789056,
      "mem_available_percent": 59.551760354263074,
      "mem_total": 8221065216,
      "mem_used": 2474393600,
      "n_cpus": 4
    },
    "per_interface_metrics": {
      "eths1": {
        "link": 1,
        "interface_up": true,
        "megabits_sent": 22322295739.378456,
        "megabits_sent_rate": 8085.2523952,
        "speed": 100000
      }
    }
  }
}

Note that all built-in functions interacting with selection input values support indexing into nested selection input data. Consider the selection input data in above. The nested values can be accessed by using dots between the keys:

si('streamer-1.per_interface_metrics.eths1.megabits_sent_rate')

Note that the whole selection input variable name must be within single quotes. The function si() is documented under general purpose functions.

`host_bitrate({})`

host_bitrate() returns the predicted bitrate (in megabits per second) of the host after the recently connected clients start ramping up in streaming quality. The function accepts an argument table with the following keys:

interface: The name of the interface to use for bitrate prediction.
Optional avg_bitrate: the average bitrate per client, defaults to 6 megabits per second.
Optional num_routers: the number of routers that can route to this host, defaults to 1. This is important to accurately predict the incoming load if multiple routers are used.
Optional host: The name of the host to use for bitrate prediction. Defaults to the current host if not provided.

Required selection input data

This function relies on the field megabits_sent_rate, supplied by the Telegraf metrics agent, as seen in example metrics. If these fields are missing from your selection input data, this function will not work.

Examples of usage:

host_bitrate({interface='eths0'})
host_bitrate({avg_bitrate=1, interface='eths0'})
host_bitrate({num_routers=2, interface='eths0'})
host_bitrate({avg_bitrate=1, num_routers=4, interface='eths0'})
host_bitrate({avg_bitrate=1, num_routers=4, host='custom_host', interface='eths0'})

host_bitrate({}) calculates the predicted bitrate as:

predicted_host_bitrate = current_host_bitrate + (recent_connections * avg_bitrate * num_routers)

`host_bitrate_custom({})`

Same functionality as host_bitrate() but uses a custom selection input variable as bitrate input instead of accessing hardware metrics. The function accepts an argument table with the following keys:

custom_bitrate_var: The name of the selection input variable to be used for accessing current host bitrate.
Optional avg_bitrate: see host_bitrate() documentation above.
Optional num_routers: see host_bitrate() documentation above.

host_bitrate_custom({custom_bitrate_var='host1_current_bitrate'})
host_bitrate_custom({avg_bitrate=1, custom_bitrate_var='host1_current_bitrate'})
host_bitrate_custom({num_routers=4, custom_bitrate_var='host1_current_bitrate'})

`host_has_bw({})`

Instead of accessing the predicted bitrate of a host through host_bitrate(), host_has_bw() returns 1 if the host is predicted to have enough bandwidth left to take on more clients after recent connections ramp up in bitrate, otherwise it returns 0. The function accepts an argument table with the following keys:

interface: see host_bitrate() documentation above.
Optional avg_bitrate: see host_bitrate() documentation above.
Optional num_routers: see host_bitrate() documentation above.
Optional host: see host_bitrate() documentation above.
Optional margin: the bitrate (megabits per second) headroom that should be taken into account during calculation, defaults to 0.

host_has_bw({}) returns whether or not the following statement is true:

predicted_host_bitrate + margin < host_bitrate_capacity

Required selection input data

host_has_bw({}) relies on the fields megabits_sent_rate and speed, supplied by the Telegraf metrics agent, as seen in example metrics. If these fields are missing from your selection input data, this function will not work.

Examples of usage:

host_has_bw({interface='eths0'})
host_has_bw({margin=10, interface='eth0'})
host_has_bw({avg_bitrate=1, interface='eth0'})
host_has_bw({num_routers=4, interface='eth0'})
host_has_bw({host='custom_host', interface='eth0'})

`host_has_bw_custom({})`

Same functionality as host_has_bw() but uses a custom selection input variable as bitrate. It also uses a number or a custom selection input variable for the capacity. The function accepts an argument table with the following keys:

custom_capacity_var: a number representing the capacity of the network interface OR the name of the selection input variable to be used for accessing host capacity.
custom_bitrate_var: see host_bitrate_custom() documentation
Optional margin: see host_has_bw() documentation above. above.
Optional avg_bitrate: see host_bitrate() documentation above.
Optional num_routers: see host_bitrate() documentation above.

Examples of usage:

host_has_bw_custom({custom_capacity_var=10000, custom_bitrate_var='streamer-1.per_interface_metrics.eths1.megabits_sent_rate'})
host_has_bw_custom({custom_capacity_var='host1_capacity', custom_bitrate_var='streamer-1.per_interface_metrics.eths1.megabits_sent_rate'})
host_has_bw_custom({margin=10, custom_capacity_var=10000, custom_bitrate_var='streamer-1.per_interface_metrics.eths1.megabits_sent_rate'})
host_has_bw_custom({avg_bitrate=1, custom_capacity_var=10000, custom_bitrate_var='streamer-1.per_interface_metrics.eths1.megabits_sent_rate'})
host_has_bw_custom({num_routers=4, custom_capacity_var=10000, custom_bitrate_var='streamer-1.per_interface_metrics.eths1.megabits_sent_rate'})

Health check functions

This section details built-in Lua functions that are meant to be used for host health checks. Note that these functions rely on data supplied by metric agents detailed in Cache hardware metrics: monitoring and routing. Make sure cache hardware metrics are supplied to the router before using any of these functions.

`cpu_load_ok({})`

The function accepts an optional argument table with the following keys:

Optional host: The name of the host. Defaults to the name of the selected host if not provided.
Optional cpu_load5_limit: The acceptable limit for the 5-minute CPU load. Defaults to 0.9 if not provided.

The function returns 1 if the five minute CPU load average is below their respective limits, and 0 otherwise.

Examples of usage:

cpu_load_ok()
cpu_load_ok({host = 'custom_host'})
cpu_load_ok({cpu_load5_limit = 0.8})
cpu_load_ok({host = 'custom_host', cpu_load5_limit = 0.8})

`memory_usage_ok({})`

The function accepts an optional argument table with the following keys:

Optional host: The name of the host. Defaults to the host of the selected host if not provided.
Optional memory_usage_limit: The acceptable limit for the memory usage. Defaults to 0.9 if not provided.

The function returns 1 if the memory usage is below the limit, and 0 otherwise.

Examples of usage:

memory_usage_ok()
memory_usage_ok({host = 'custom_host'})
memory_usage_ok({memory_usage_limit = 0.7})
memory_usage_ok({host = 'custom_host', memory_usage_limit = 0.7})

`interfaces_online({})`

The function accepts an argument table with the following keys:

Required interfaces: A string or a table of strings representing the network interfaces to check.
Optional host: The name of the host. Defaults to the host of the selected host if not provided.

The function returns 1 if all the specified interfaces are online, and 0 otherwise.

Required selection input data

This function relies on the fields link and interface_up, supplied by the Telegraf metrics agent, as seen in example metrics. If these fields are missing from your selection input data, this function will not work.

Examples of usage:

interfaces_online({interfaces = 'eth0'})
interfaces_online({interfaces = {'eth0', 'eth1'}})
interfaces_online({host = 'custom_host', interfaces = 'eth0'})
interfaces_online({host = 'custom_host', interfaces = {'eth0', 'eth1'}})

`health_check({})`

The function accepts an optional argument table with the following keys:

Required interfaces: A string or a table of strings representing the network interfaces to check.
Optional host: The name of the host. Defaults to the host of the selected host if not provided.
Optional cpu_load5_limit: The acceptable limit for the 5-minute CPU load. Defaults to 0.9 if not provided.
Optional memory_usage_limit: The acceptable limit for the memory usage. Defaults to 0.9 if not provided.

The function calls the health check functions cpu_load_ok({}), memory_usage_ok({}) and interfaces_online({}). The functions returns 1 if all these functions returned 1, otherwise it returns 0.

Examples of usage:

health_check({interfaces = 'eths0'})
health_check({host = 'custom_host', interfaces = 'eths0'})
health_check({cpu_load5_limit = 0.7, memory_usage_limit = 0.8, interfaces = 'eth0'})
health_check({host = 'custom_host', cpu_load5_limit = 0.7, memory_usage_limit = 0.8, interfaces = {'eth0', 'eth1'}})

General purpose functions

The router supplies a number of general purpose Lua functions.

`always()`

Always returns 1.

`never()`

Always returns 0. Useful for temporarily disabling caches by using it as a health check.

Examples of usage:

always()
never()

`si(si_name)`

The function reads the value of the selection input variable si_name and returns it if it exists, otherwise it returns 0. The function accepts a string argument for the selection input variable name.

Examples of usage:

si('some_selection_input_variable_name')
si('streamer-1.per_interface_metrics.eths1.megabits_sent_rate')

Comparison functions

All comparison functions use the form function(si_name, value) and compares the selection input value with the name si_name with value.

`ge(si_name, value)` - greater than or equal

`gt(si_name, value)` - greater than

`le(si_name, value)` - less than or equal

`lt(si_name, value)` - less than

`eq(si_name, value)` - equal to

`neq(si_name, value)` - not equal to

Examples of usage:

ge('streamer-1.hardware_metrics.mem_available_percent', 30)
gt('streamer-1.hardware_metrics./.free', 1000000000)
le('streamer-1.hardware_metrics.cpu_load5', 0.8)
lt('streamer-1.per_interface_metrics.eths1.megabits_sent_rate', 9000)
eq('streamer-1.per_interface_metrics.eths1.link.', 1)
neq('streamer-1.hardware_metrics.n_cpus', 4)

Session checking functions

`in_subnet(subnet)`

Returns 1 if the current session belongs to subnet, otherwise it returns 0. See Subnets API for more details on how to use subnets in routing. The function accepts a string argument for the subnet name.

Examples of usage:

in_subnet('stockholm')
in_subnet('unserviced_region')
in_subnet('some_other_subnet')

These functions checks the current session’s session groups.

`in_session_group(session_group)`

Returns 1 if the current session has been classified into session_group, otherwise it returns 0. The function accepts a string argument for the session group name.

`in_any_session_group({})`

Returns 1 if the current session has been classified into any of session_groups, otherwise it returns 0. The function accepts a table array of strings as argument for the session group names.

`in_all_session_groups({})`

Returns 1 if the current session has been classified into all of session_groups, otherwise it returns 0. The function accepts a table array of strings as argument for the session group names.

Examples of usage:

in_session_group('safari_browser')
in_any_session_group({ 'in_europe', 'in_asia'})
in_all_session_group({ 'vod_content', 'in_america'})

Configuration examples

Many of the functions documented are suitable to use in host health checks. To configure host health checks, see configuring CDNs and hosts. Here are some configuration examples of using the built-in Lua functions, utilizing the example metrics:

"healthChecks": [
    "gt('streamer-1.hardware_metrics.mem_available_percent', 20)", // More than 20% memory is left
    "lt('streamer-1.per_interface_metrics.eths1.megabits_sent_rate', 9000)" // Current bitrate is lower than 9000 Mbps
    "host_has_bw({host='streamer-1', interface='eths1', margin=1000})", // host_has_bw() uses 'streamer-1.per_interface_metrics.eths1.speed' to determine if there is enough bandwidth left with a 1000 Mbps margin
    "interfaces_online({host='streamer-1', interfaces='eths1'})",
    "memory_usage_ok({host='streamer-1'})",
    "cpu_load_ok({host='streamer-1'})",
    "health_check({host='streamer-1', interfaces='eths1'})" // Combines interfaces_online(), memory_usage_ok(), cpu_load_ok()
]

5.4.5.2 - Global Lua Tables

Details on all global Lua tables and the data they contain.

There are multiple global tables containing important data available while writing Lua code for the router.

`selection_input`

Contains arbitrary, custom fields fed into the router by clients, see API overview for details on how to inject data into this table.

Note that the selection_input table is iterable.

Usage examples:

print(selection_input['some_value'])

-- Iterate over table
if selection_input then
    for k, v in pairs(selection_input) do
        print('here is '..'selection_input!')
        print(k..'='..v)
    end
else
    print('selection_input is nil')
end

`session_groups`

Defines a mapping from session group name to boolean, indicating whether the session belongs to the session group or not.

Usage examples:

if session_groups.vod then print('vod') else print('not vod') end
if session_groups['vod'] then print('vod') else print('not vod') end

`session_count`

Provides counters of number of session types per session group. The table uses the structure qoe_score.<session_type>.<session_group>.

Usage examples:

print(session_count.instream.vod)
print(session_count.initial.vod)

`qoe_score`

Provides the quality of experience score per host per session group. The table uses the structure qoe_score.<host>.<session_group>.

Usage examples:

print(qoe_score.host1.vod)
print(qoe_score.host1.live)

`request`

Contains data related to the HTTP request between the client and the router.

request.method
- Description: HTTP request method.
- Type: string
- Example: 'GET', 'POST'
request.body
- Description: HTTP request body string.
- Type: string or nil
- Example: '{"foo": "bar"}'
request.major_version
- Description: Major HTTP version such as x in HTTP/x.1.
- Type: integer
- Example: 1
request.minor_version
- Description: Minor HTTP version such as x in HTTP/1.x.
- Type: integer
- Example: 1
request.protocol
- Description: Transfer protocol variant.
- Type: string
- Example: 'HTTP', 'HTTPS'
request.client_ip
- Description: IP address of the client issuing the request.
- Type: string
- Example: '172.16.238.128'
request.path_with_query_params
- Description: Full request path including query parameters.
- Type: string
- Example: '/mycontent/superman.m3u8?b=y&c=z&a=x'
request.path
- Description: Request path without query parameters.
- Type: string
- Example: '/mycontent/superman.m3u8'
request.query_params
- Description: The query parameter string.
- Type: string
- Example: 'b=y&c=z&a=x'
request.filename
- Description: The part of the path following the final slash, if any.
- Type: string
- Example: 'superman.m3u8'
request.subnet
- Description: Subnet of client_ip.
- Type: string or nil
- Example: 'all'

`session`

Contains data related to the current session.

session.client_ip
- Description: Alias for request.client_ip. See documentation for table request above.
session.path_with_query_params
- Description: Alias for request.path_with_query_params. See documentation for table request above.
session.path
- Description: Alias for request.path. See documentation for table request above.
session.query_params
- Description: Alias for request.query_params. See documentation for table request above.
session.filename
- Description: Alias for request.filename. See documentation for table request above.
session.subnet
- Description: Alias for request.subnet. See documentation for table request above.
session.host
- Description: ID of the currently selected host for the session.
- Type: string or nil
- Example: 'host1'
session.id
- Description: ID of the session.
- Type: string
- Example: '8eb2c1bdc106-17d2ff-00000000'
session.session_type
- Description: Type of the session.
- Type: string
- Example: 'initial' or 'instream'. Identical to the value of the Type argument of the session translation function.
session.is_managed
- Description: Identifies managed sessions.
- Type: boolean
- Example: true if Type/session.session_type is 'instream'

`request_headers`

Contains the headers from the request between the client and the router, keyed by name.

Usage example:

print(request_headers['User-Agent'])

`request_query_params`

Contains the query parameters from the request between the client and the router, keyed by name.

Usage example:

print(request_query_params.a)

`session_query_params`

Alias for metatable request_query_params.

`response`

Contains data related to the outgoing response apart from the headers.

response.body
- Description: HTTP response body string.
- Type: string or nil
- Example: '{"foo": "bar"}'
response.code
- Description: HTTP response status code.
- Type: integer
- Example: 200, 404
response.text
- Description: HTTP response status text.
- Type: string
- Example: 'OK', 'Not found'
response.major_version
- Description: Major HTTP version such as x in HTTP/x.1.
- Type: integer
- Example: 1
response.minor_version
- Description: Minor HTTP version such as x in HTTP/1.x.
- Type: integer
- Example: 1
response.protocol
- Description: Transfer protocol variant.
- Type: string
- Example: 'HTTP', 'HTTPS'

`response_headers`

Contains the response headers keyed by name.

Usage example:

print(response_headers['User-Agent'])

5.4.5.3 - Request Translation Function

Instructions for how to write a function to modify incoming requests before routing decisions are being made.

Specifies the body of a Lua function that inspects every incoming HTTP request and overwrites individual fields before further processing by the router.

Returns nil when nothing is to be changed, or HTTPRequest(t) where t is a table with any of the following optional fields:

Method
- Description: Replaces the HTTP request method in the request being processed.
- Type: string
- Example: 'GET', 'POST'
Path
- Description: Replaces the request path in the request being processed.
- Type: string
- Example: '/mycontent/superman.m3u8'
ClientIp
- Description: Replaces client IP address in the request being processed.
- Type: string
- Example: '172.16.238.128'
Body
- Description: Replaces body in the request being processed.
- Type: string or nil
- Example: '{"foo": "bar"}'
QueryParameters
- Description: Adds, removes or replaces individual query parameters in the request being processed.
- Type: nested table (indexed by number) representing an array of query parameters as {[1]='Name',[2]='Value'} pairs that are added to the request being processed, or overwriting existing query parameters with colliding names. To remove a query parameter from the request, specify nil as value, i.e. QueryParameters={..., {[1]='foo',[2]=nil} ...}. Returning a query parameter with a name but no value, such as a in the request '/index.m3u8?a&b=22' is currently not supported.
Headers
- Description: Adds, removes or replaces individual headers in the request being processed.
- Type: nested table (indexed by number) representing an array of request headers as {[1]='Name',[2]='Value'} pairs that are added to the request being processed, or overwriting existing request headers with colliding names. To remove a header from the request, specify nil as value, i.e. Headers={..., {[1]='foo',[2]=nil} ...}. Duplicate names are supported. A multi-value header such as Foo: bar1,bar2 is defined by specifying Headers={..., {[1]='foo',[2]='bar1'}, {[1]='foo',[2]='bar2'}, ...}.

Example of a request_translation_function body that sets the request path to a hardcoded value and adds the hardcoded query parameter a=b:

-- Statements go here
print('Setting hardcoded Path and QueryParameters')
return HTTPRequest({
  Path = '/content.mpd',
  QueryParameters = {
    {'a','b'}
  }
})

Arguments

The following (iterable) arguments will be known by the function:

`QueryParameters`

Type: nested table (indexed by number).
Description: Array of query parameters as {[1]='Name',[2]='Value'} pairs that were present in the query string of the request. Format identical to the HTTPRequest.QueryParameters-field specified for the return value above.

Example usage:

for _, queryParam in pairs(QueryParameters) do
  print(queryParam[1]..'='..queryParam[2])
end

`Headers`

Type: nested table (indexed by number).
Description: Array of request headers as {[1]='Name',[2]='Value'} pairs that were present in the request. Format identical to the HTTPRequest.Headers-field specified for the return value above. A multi-value header such as Foo: bar1,bar2 is seen in request_translation_function as Headers={..., {[1]='foo',[2]='bar1'}, {[1]='foo',[2]='bar1'}, ...}.

Example usage:

for _, header in pairs(Headers) do
  print(header[1]..'='..header[2])
end

Additional data

In addition to the arguments above, the following Lua tables, documented in Global Lua Tables, provide additional data that is available when executing the request translation function:

If the request translation function modifies the request, the request, request_query_params and request_headers tables will be updated with the modified request and made available to the routing rules.

5.4.5.4 - Session Translation Function

Instructions for how to write a function to modify a client session to affect how it is handled by the router.

Specifies the body of a Lua function that inspects a newly created session and may override its suggested type from “initial” to “instream” or vice versa. A number of helper functions are provided to simplify changing the session type.

Returns nil when the session type is to remain unchanged, or Session(t) where t is a table with a single field:

Type
- Description: New type of the session.
- Type: string
- Example: 'instream', 'initial'

Basic Configuration

It is possible to configure the maximum number of simultaneous managed sessions on the router. If the maximum number is reached, no more managed sessions can be created. Using confcli, it can be configured by running

$ confcli services.routing.tuning.general.maxActiveManagedSessions
{
    "maxActiveManagedSessions": 1000
}
$ confcli services.routing.tuning.general.maxActiveManagedSessions 900
services.routing.tuning.general.maxActiveManagedSessions = 900

Common Arguments

While executing the session translation function, the following arguments are available:

Type: The current type of the session ('instream' or 'initial').

Usage examples:

-- Flip session type
local newType = 'initial'
if Type == 'initial' then
    newType = 'instream'
end
print('Changing session type from ' .. Type .. ' to ' .. newType)
return Session({['Type'] = newType})

Session Translation Helper Functions

The standard Lua library prodives four helper functions to simplify the configuration of the session translation function:

`set_session_type(session_type)`

This function will set the session type to the supplied session_type and the maximum number of sessions of that type has not been reached.

Parameters

session_type: The type of session to create, possible values are ‘initial’ or ‘instream’.

Usage Examples

return set_session_type('instream')
return set_session_type('initial')

`set_session_type_if_in_group(session_type, session_group)`

This function will set the session type to the supplied session_type if the session is part of session_group and the maximum number of sessions of that type has not been reached.

Parameters

session_type: The type of session to create, possible values are ‘initial’ or ‘instream’.
session_group: The name of the session group.

Usage Examples

return set_session_type_if_in_group('instream', 'sg1')

`set_session_type_if_in_all_groups(session_type, session_groups)`

This function will set the session type to the supplied session_type if the session is part of all session groups given by session_groups and the maximum number of sessions of that type has not been reached.

Parameters

session_type: The type of session to create, possible values are ‘initial’ or ‘instream’.
session_groups: A list of session group names.

Usage Examples

return set_session_type_if_in_all_groups('instream', {'sg1', 'sg2'})

`set_session_type_if_in_any_group(session_type)`

This function will set the session type to the supplied session_type if the session is part of one or more of the session groups given by session_groups and the maximum number of sessions of that type has not been reached.

Parameters

session_type: The type of session to create, possible values are ‘initial’ or ‘instream’.
session_groups: A list of session group names.

Usage Examples

return set_session_type_if_in_any_group('instream', {'sg1', 'sg2'})

Configuration

Using confcli, example of how the functions above can be used in the session translation function can be configured by running any of

$ confcli services.routing.translationFunctions.session "return set_session_type('instream')"
services.routing.translationFunctions.session = "return set_session_type('instream')"

$ confcli services.routing.translationFunctions.session "return set_session_type_if_in_group('instream', 'sg1')"
services.routing.translationFunctions.session = "return set_session_type_if_in_group('instream', 'sg1')"

$ confcli services.routing.translationFunctions.session "return set_session_type_if_in_all_groups('instream', {'sg1', 'sg2'})"
services.routing.translationFunctions.session = "return set_session_type_if_in_all_groups('instream', {'sg1', 'sg2'})"

$ confcli services.routing.translationFunctions.session "return set_session_type_if_in_any_group('instream', {'sg1', 'sg2'})"
services.routing.translationFunctions.session = "return set_session_type_if_in_any_group('instream', {'sg1', 'sg2'})"

Additional data

In addition to the arguments above, the following Lua tables, documented in Global Lua Tables, provide additional data that is available when executing the response translation function:

The selection_input table will not change while a routing request is handled. A request_translation_function and the corresponding response_translation_function will see the same selection_input table, even if the selection data is updated while the request is being handled.

5.4.5.5 - Host Request Translation Function

Instructions on how to write a function to modify requests that are sent to hosts.

The host request translation function defines a Lua function that modifies HTTP requests sent to a host. These hosts are configured in services.routing.hostGroups.

Hosts can receive requests for a manifest. A regular host will respond with the manifest itself, while a redirecting host and a DNS host will respond with a redirection to a streamer. This function can modify all these types of requests.

The function returns nil when nothing is to be changed, or HTTPRequest(t) where t is a table with any of the following optional fields:

Method
- Description: Replaces the HTTP request method in the request being processed.
- Type: string
- Example: 'GET', 'POST'
Path
- Description: Replaces the request path in the request being processed.
- Type: string
- Example: '/mycontent/superman.m3u8'
Body
- Description: Replaces body in the request being processed.
- Type: string or nil
- Example: '{"foo": "bar"}'
QueryParameters
- Description: Adds, removes or replaces individual query parameters in the request being processed.
- Type: nested table (indexed by number) representing an array of query parameters as {[1]='Name',[2]='Value'} pairs that are added to the request being processed, or overwriting existing query parameters with colliding names. To remove a query parameter from the request, specify nil as value, i.e. QueryParameters={..., {[1]='foo',[2]=nil} ...}. Returning a query parameter with a name but no value, such as a in the request '/index.m3u8?a&b=22' is currently not supported.
Headers
- Description: Adds, removes or replaces individual headers in the request being processed.
- Type: nested table (indexed by number) representing an array of request headers as {[1]='Name',[2]='Value'} pairs that are added to the request being processed, or overwriting existing request headers with colliding names. To remove a header from the request, specify nil as value, i.e. Headers={..., {[1]='foo',[2]=nil} ...}. Duplicate names are supported. A multi-value header such as Foo: bar1,bar2 is defined by specifying Headers={..., {[1]='foo',[2]='bar1'}, {[1]='foo',[2]='bar2'}, ...}.
Host
- Description: Replaces the host that the request is sent to.
- Type: string
- Example: 'new-host.example.com', '192.0.2.7'
Port
- Description: Replaces the TCP port that the request is sent to.
- Type: number
- Example: 8081
Protocol
- Description: Decides which protocol that will be used for sending the request. Valid protocols are 'HTTP' and 'HTTPS'.
- Type: string
- Example: 'HTTP', 'HTTPS'

Example of a host_request_translation_function body that sets the request path to a hardcoded value and adds the hardcoded query parameter a=b:

-- Statements go here
print('Setting hardcoded Path and QueryParameters')
return HTTPRequest({
  Path = '/content.mpd',
  QueryParameters = {
    {'a','b'}
  }
})

Arguments

The following (iterable) arguments will be known by the function:

`QueryParameters`

Type: nested table (indexed by number).
Description: Array of query parameters as {[1]='Name',[2]='Value'} pairs that are present in the query string of the request from the client to the router. Format identical to the HTTPRequest.QueryParameters-field specified for the return value above.

Example usage:

for _, queryParam in pairs(QueryParameters) do
  print(queryParam[1]..'='..queryParam[2])
end

`Headers`

Type: nested table (indexed by number).
Description: Array of request headers as {[1]='Name',[2]='Value'} pairs that are present in the request from the client to the router. Format identical to the HTTPRequest.Headers-field specified for the return value above. A multi-value header such as Foo: bar1,bar2 is seen in host_request_translation_function as Headers={..., {[1]='foo',[2]='bar1'}, {[1]='foo',[2]='bar1'}, ...}.

Example usage:

for _, header in pairs(Headers) do
  print(header[1]..'='..header[2])
end

Global tables

The following non-iterable global tables are available for use by the host_request_translation_function.

Table `outgoing_request`

The outgoing_request table contains the request that is to be sent to the host.

outgoing_request.method
- Description: HTTP request method.
- Type: string
- Example: 'GET', 'POST'
outgoing_request.body
- Description: HTTP request body string.
- Type: string or nil
- Example: '{"foo": "bar"}'
outgoing_request.major_version
- Description: Major HTTP version such as x in HTTP/x.1.
- Type: integer
- Example: 1
outgoing_request.minor_version
- Description: Minor HTTP version such as x in HTTP/1.x.
- Type: integer
- Example: 1
outgoing_request.protocol
- Description: Transfer protocol variant.
- Type: string
- Example: 'HTTP', 'HTTPS'

Table `outgoing_request_headers`

Contains the request headers from the request that is to be sent to the host, keyed by name.

Example:

print(outgoing_request_headers['X-Forwarded-For'])

Multiple values are separated with a comma.

Additional data

In addition to the arguments above, the following Lua tables, documented in Global Lua Tables, provide additional data that is available when executing the request translation function:

5.4.5.6 - Response Translation Function

Instructions for how to write a function to modify outgoing responses after a routing decision has been made.

Specifies the body of a Lua function that inspects every outgoing HTTP response and overwrites individual fields before being sent to the client.

Returns nil when nothing is to be changed, or HTTPResponse(t) where t is a table with any of the following optional fields:

Code
- Description: Replaces status code in the response being sent.
- Type: integer
- Example: 200, 404
Text
- Description: Replaces status text in the response being sent.
- Type: string
- Example: 'OK', 'Not found'
MajorVersion
- Description: Replaces major HTTP version such as x in HTTP/x.1 in the response being sent.
- Type: integer
- Example: 1
MinorVersion
- Description: Replaces minor HTTP version such as x in HTTP/1.x in the response being sent.
- Type: integer
- Example: 1
Protocol
- Description: Replaces protocol in the response being sent.
- Type: string
- Example: 'HTTP', 'HTTPS'
Body
- Description: Replaces body in the response being sent.
- Type: string or nil
- Example: '{"foo": "bar"}'
Headers
- Description: Adds, removes or replaces individual headers in the response being sent.
- Type: nested table (indexed by number) representing an array of response headers as {[1]='Name',[2]='Value'} pairs that are added to the response being sent, or overwriting existing request headers with colliding names. To remove a header from the response, specify nil as value, i.e. Headers={..., {[1]='foo',[2]=nil} ...}. Duplicate names are supported. A multi-value header such as Foo: bar1,bar2 is defined by specifying Headers={..., {[1]='foo',[2]='bar1'}, {[1]='foo',[2]='bar2'}, ...}.

Example of a response_translation_function body that sets the Location header to a hardcoded value:

-- Statements go here
print('Setting hardcoded Location')
return HTTPResponse({
  Headers = {
    {'Location', 'cdn1.com/content.mpd?a=b'}
  }
})

Arguments

The following (iterable) arguments will be known by the function:

`Headers`

Type: nested table (indexed by number).
Description: Array of response headers as {[1]='Name',[2]='Value'} pairs that are present in the response being sent. Format identical to the HTTPResponse.Headers-field specified for the return value above. A multi-value header such as Foo: bar1,bar2 is seen in response_translation_function as Headers={..., {[1]='foo',[2]='bar1'}, {[1]='foo',[2]='bar1'}, ...}.

Example usage:

for _, header in pairs(Headers) do
  print(header[1]..'='..header[2])
end

Additional data

In addition to the arguments above, the following Lua tables, documented in Global Lua Tables, provide additional data that is available when executing the response translation function:

5.5 - Trusted proxies

How to configure trusted proxies to control proxied connections

When a request with the header X-Forwarded-For is sent to the router, the router will check if the client is in the list of trusted proxies. If the client is not a trusted proxy, the router will drop the connection, returning an empty reply to the client. If the client is a trusted proxy, the IP address defined in the X-Forwarded-For will be regarded as the client’s IP address.

The list of trusted proxies can be configured by modifying the configuration field services.routing.settings.trustedProxies with the IP addresses of trusted proxies:

$ confcli services.routing.settings.trustedProxies -w
Running wizard for resource 'trustedProxies'
<A list of IP addresses from which the proxy IP address of requests with the X-Forwarded-For header defined are checked. If the IP isn't in this list, the connection is dropped. (default: [])>

Hint: Hitting return will set a value to its default.
Enter '?' to receive the help string

trustedProxies <A list of IP addresses from which the proxy IP address of requests with the X-Forwarded-For header defined are checked. If the IP isn't in this list, the connection is dropped. (default: [])>: [
  trustedProxy (default: ): 1.2.3.4
  Add another 'trustedProxy' element to array 'trustedProxies'? [y/N]: n
]
Generated config:
{
  "trustedProxies": [
    "1.2.3.4"
  ]
}
Merge and apply the config? [y/n]: y

Note that by configuring 0.0.0.0/0 as a trusted proxy, all proxied requests will be trusted.

5.6 - Confd Auto Upgrade Tool

Applying automatic configuration migrations

The confd-auto-upgrade tool is a simple utility to automatically migrate the confd configuration schema between different versions of the Director. Starting with version 1.12.0, it is possible to automatically apply the necessary configuration changes in a controlled and predictable manner. While this tool is intended to help transition the configuration format between the different versions, it is not a substitute for proper backups, and while downgrading to an earlier version, it may not be possible to recover previously modified or deleted configuration values.

When using the tool, both the “from” and “to” versions must be specified. Internally, the tool will calculate a list of migrations which must be applied to transition between the given versions, and apply them, outputting the final configuration to standard output. The current configuration can either be piped in to the tool via standard input, or supplied as a static file. Providing a “from” version which is later than the “to” version will result in the downgrade migrations being applied in reverse order, effectively downgrading the configuration to the lower version.

For convenience, the tool is deployed to the ACD Nodes automatically at install time as a standard Podman container, however since it is not intended to run as a service, only the image will be present, not a running container.

Performing the Upgrade

In the following example scenario, a system with version 1.10.1 has been upgraded to 1.14.0. Before upgrading a backup of the configuration was taken and saved to current_config.json.

Using the image and tag as determined in the above section. Issue the following command:

cat current_config.json | \
  podman run -i --rm images.edgeware.tv/acd-confd-migration:1.14.0 \
  --in - --from 1.10.1 --to 1.14.0 \
  | tee upgraded_config.json

In the above example, the updated configuration is saved to upgraded_config.json. It is recommended to manually verify the generated configuration, and after which apply the config to confd by using cat upgraded_config.json | confcli -i.

It is also possible to combine the two commands, by piping the output of the auto-upgrade tool directly to confcli -i. E.g.

cat current_config.json | podman run ... | tee upgraded_config.json | confcli -i

This will save a backup of the upgraded configuration to upgraded_config.json and at the same time apply the changes to confd immediately.

Downgrading the Configuration

The steps for downgrading the configuration are exactly the same as for upgrade except for the --from and --to versions should be swapped. E.g. --from 1.14.0 --to 1.10.1. Keep in mind however, that during an upgrade some configuration properties may have been deleted or modified, and while downgrading over those steps, some data loss may occur. In those cases, it may be easier and safer to simply restore from backup. In most cases where configuration properties are removed during upgrade, the corresponding downgrade will simply restore the default values of those properties.

6 - Operations

Operators Guide

This guide describes how to perform day-to-day operations of the ACD Router and its associated services, collectively known as the Director.

Component Overview

To effectively operate the Director software, it is important to understand the composition of the various software components and how they are deployed.

Each Director instance functions as an independent system, comprising multiple containerized services. These containers are managed by a standard container runtime and are seamlessly integrated with the host’s operating system to enhance the overall operator experience.

The containers are managed by the Podman container runtime, which operates without additional daemon services running on the host. Unlike Docker, Podman manages each container as a separate process, eliminating the reliance on a shared daemon and mitigating the risk of a single-point-of-failure scenario.

Although several distinct services make up the Director, the primary component is the router. The router is responsible for listening for incoming requests, processing the request, and redirecting the client to the appropriate host, or CDN to deliver the requested content.

Two additional containers are responsible for configuration management. Those are confd and confd-transformer. The former manages a local database of configuration metadata and provides a REST API for managing the configuration. The confd-transformer simply listens for configuration changes from confd and adapts that configuration to a format suitable for the router to ingest. For additional information about setting up and using confd see here..

The next two components, the edns-proxy and the convoy-bridge allow the router to communicate with an EDNS server for EDNS-based routing, and with synchronization with Convoy respectively. Additional information about the EDNS-Proxy is available here.. For the Convoy Bridge service see here..

The remaining containers are useful for metrics, monitoring, and alerting. These include prometheus and grafana for monitoring and analytics, and alertmanager for monitoring and alarms.

6.1 - Services

Starting / Stopping / Monitoring Services

Each container shipped with the Director is fully-integrated with the systemd service on the host, enabling easy management using standard systemd commands. The logs for each container are also full-integrated with journald to simplify troubleshooting.

In order to integrate the Podman containers with systemd, a common prefix of acd- has been applied to each service name. For example the router container is managed by the service acd-router, and the confd container is managed by the service acd-confd. These same prefixed names apply while fetching logs via journald. This common prefix aids in grouping the related services as well as provides simpler filtering for tab-completion.

Starting / Stopping Services

Standard systemd commands should be used to start and stop the services.

systemctl start acd-router - Starts the router container.
systemctl stop acd-router - Stops the router container.
systemctl status acd-router - Displays the status of the router container.

Due to the limitation of needing the acd- prefix, it provides the ability to work with all ACD services in a group. For example:

systemctl status 'acd-*' - Display the status of all installed ACD components.
systemctl start 'acd-*' - Start all ACD components.

Logging

Each ACD component corresponds to a journal entry with the same unit name, with the acd- prefix. Standard journald commands can be used to view and manage the logging.

journalctl -u acd-router - Display the logs for the router container

Access Log

HTTP access logging can be enabled by typing this:

confcli services.routing.tuning.general.accessLog true

When access logging is enabled, the Director will log all content requests. The logs can be obtained from journald by using the following command:

journalctl SYSLOG_IDENTIFIER=router ACCESSLOG=1

This will output the router’s access logs in a standard format.

Troubleshooting

Some additional logging may be available in the filesystem, the paths of which can be determined by executing the ew-sysinfo command. See Diagnostics. for additional details.

7 - Convoy Bridge

Convoy Bridge Integration

The convoy-bridge is an optional integration service, pre-installed alongside the router which provides two-way communication between the router and a separate Convoy installation.

The convoy-bridge is designed to allow the Convoy account metadata to be available from within the router for such use-cases as inserting the account specific prefixes in the redirect URL and validating per-account internal security tokens. The service works by periodically polling the Convoy server for changes to the configuration, and when detected, the relevant configuration information is pushed to the router.

In addition, the convoy-bridge has the ability to integrate the router with the Convoy analytics service, such that client sessions started by the router are properly collected by Convoy, and are available in the dashboards.

Configuration

The convoy-bridge service is configured using confcli on the router host. All configuration for the convoy-bridge exists under the path integration.convoy.bridge.

{
  "logLevel": "info",
  "accounts": {
    "enabled": true,
    "dbUrl": "mysql://convoy:eith7jee@convoy:3306",
    "dbPollInterval": 60
  },
  "analytics": {
    "enabled": true,
    "brokers": ["broker1:9092", "broker2:9092"],
    "batchInterval": 10,
    "maxBatchSize": 500
  },
  "otherRouters": [
    {
      "url": "https://router2:5001",
      "apiKey": "key1",
      "validateCerts": true
    }
  ]
}

In the above configuration block, there are three main sections. The accounts section enables fetching account metadata from Convoy towards the router. The analytics section controls the integration between the router and the Convoy analytics service. The otherRouters section is used to synchronize additional router instances. The local router instance will always be implicitly included. Additional routers listed in this section will be handled by this instance of the convoy-bridge service.

Logging

The logs are available in the system journal and can be viewed using:

journalctl -u acd-convoy-bridge

8 - Monitoring

Monitoring

8.1 - System troubleshooting

Using ew-sysinfo to monitor and troubleshoot ESB3024

ESB3024 contains the tool ew-sysinfo that gives an overview of how the system is doing. Simply use the command and the tool will output information about the system and the installed ESB3024 services.

The output format can be changed using the --format flag, possible values are human (default) and json, e.g.:

$ ew-sysinfo
system:
   os: ['5.4.17-2136.321.4.el8uek.x86_64', 'Oracle Linux Server 8.8']
   cpu_cores: 2
   cpu_load_average: [0.03, 0.03, 0.0]
   memory_usage: 478 MB
   memory_load_average: [0.03, 0.03, 0.0]
   boot_time: 2023-09-08T08:30:57Z
   uptime: 6 days, 3:43:44.640665
   processes: 122
   open_sockets:
      ipv4: 12
      ipv6: 18
      ip_total: 30
      tcp_over_ipv4: 9
      tcp_over_ipv6: 16
      tcp_total: 25
      udp_over_ipv4: 3
      udp_over_ipv6: 2
      udp_total: 5
      total: 145
system_disk (/):
   total: 33271 MB
   used: 7978 MB (24.00%)
   free: 25293 MB
journal_disk (/run/log/journal):
   total: 1954 MB
   used: 217 MB (11.10%)
   free: 1736 MB
vulnerabilities:
   meltdown: Mitigation: PTI
   spectre_v1: Mitigation: usercopy/swapgs barriers and __user pointer sanitization
   spectre_v2: Mitigation: Retpolines, STIBP: disabled, RSB filling, PBRSB-eIBRS: Not affected
processes:
   orc-re:
      pid: 177199
      status: sleeping
      cpu_usage_percent: 1.0%
      cpu_load_average: 131.11%
      memory_usage: 14 MB (0.38%)
      num_threads: 10
hints:
   get_raw_router_config: cat /opt/edgeware/acd/router/cache/config.json
   get_confd_config: cat /opt/edgeware/acd/confd/store/__active
   get_router_logs: journalctl -u acd-router
   get_edns_proxy_logs: journalctl -u acd-edns-proxy
   check_firewall_status: systemctl status firewalld
   check_firewall_config: iptables -nvL

# For --format=json, it's recommended to pipe the output to a JSON interpreter
# such as jq

$ ew-sysinfo --format=json | jq
{
  "system": {
    "os": [
      "5.4.17-2136.321.4.el8uek.x86_64",
      "Oracle Linux Server 8.8"
    ],
    "cpu_cores": 2,
    "cpu_load_average": [
      0.01,
      0.0,
      0.0
    ],
    "memory_usage": "479 MB",
    "memory_load_average": [
      0.01,
      0.0,
      0.0
    ],
    "boot_time": "2023-09-08 08:30:57",
    "uptime": "6 days, 5:12:24.617114",
    "processes": 123,
    "open_sockets": {
      "ipv4": 13,
      "ipv6": 18,
      "ip_total": 31,
      "tcp_over_ipv4": 10,
      "tcp_over_ipv6": 16,
      "tcp_total": 26,
      "udp_over_ipv4": 3,
      "udp_over_ipv6": 2,
      "udp_total": 5,
      "total": 146
    }
  },
  "system_disk (/)": {
    "total": "33271 MB",
    "used": "7977 MB (24.00%)",
    "free": "25293 MB"
  },
  "journal_disk (/run/log/journal)": {
    "total": "1954 MB",
    "used": "225 MB (11.50%)",
    "free": "1728 MB"
  },
  "vulnerabilities": {
    "meltdown": "Mitigation: PTI",
    "spectre_v1": "Mitigation: usercopy/swapgs barriers and __user pointer sanitization",
    "spectre_v2": "Mitigation: Retpolines, STIBP: disabled, RSB filling, PBRSB-eIBRS: Not affected"
  },
  "processes": {
    "orc-re": {
      "pid": 177199,
      "status": "sleeping",
      "cpu_usage_percent": "0.0%",
      "cpu_load_average": "137.63%",
      "memory_usage": "14 MB (0.38%)",
      "num_threads": 10
    }
  }
}

Note that your system might have different monitored processes and field names.

The field hints is different from the rest. It lists common commands that can be used to further monitor system performance, useful for quickly troubleshooting a faulty system.

8.2 - Scraping data with Prometheus

Prometheus is a third-party data scraper which is installed as a containerized service in the default installation of ESB3024 Router. It periodically reads metrics data from different services, such as acd-router, aggregates it and makes it available to other services that visualize the data. Those services include Grafana and Alertmanager.

The Prometheus configuration file can be found on the host at /opt/edgeware/acd/prometheus/prometheus.yaml.

Accessing Prometheus

Prometheus has a web interface that is listening for HTTP connections on port 9090. There is no authentication, so anyone who has access to the host that is running Prometheus can access the interface.

Starting / Stopping Prometheus

After the service is configured, it can be managed via systemd, under the service unit acd-prometheus.

systemctl start acd-prometheus

Logging

The container logs are automatically published to the system journal, under the same unit descriptor, and can be viewed using journalctl

journalctl -u acd-prometheus

8.3 - Visualizing data with Grafana

8.3.1 - Managing Grafana

Grafana displays graphs based on data from Prometheus. A default deployment of Grafana is running in a container alongside ESB3024 Router.

Grafana’s configuration and runtime files are stored under /opt/edgeware/acd/grafana. It comes with default dashboards that are documented at Grafana dashboards.

Accessing Grafana

Grafana’s web interface is listening for HTTP connections on port 3000. It has two default accounts, edgeware and admin.

The edgeware account can only view graphs, while the admin account can also edit graphs. The accounts with default passwords are shown in the table below.

Account	Default password
`edgeware`	`edgeware`
`admin`	`edgeware`

Starting / Stopping Grafana

Grafana can be managed via systemd, under the service unit acd-grafana.

systemctl start acd-grafana

Logging

The container logs are automatically published to the system journal, under the same unit descriptor, and can be viewed using journalctl

journalctl -u acd-grafana

8.3.2 - Grafana Dashboards

Dashboards in default Grafana installation

Grafana will be populated with pre-configured graphs which present some metrics on a time scale. Below is a comprehensive list of those dashboards, along with short descriptions.

Router Monitoring dashboard

This dashboard is by default set as home directory - it’s what user will see after logging in.

Number Of Initial Routing Decisions

HTTP Status Codes

Total number of responses sent back to incoming requests, shown by their status codes. Metric: client-response-status

Incoming HTTP and HTTPS Requests

Total number of incoming requests that were deemed valid, divided into SSL and Unencrypted categories. Metric: num_valid_http_requests

Debugging Information dashboard

Number of Lua Exceptions

Number of exceptions encountered so far while evaluating Lua rules. Metric: lua_num_errors

Number of Lua Contexts

Number of active Lua interpreters, both running and idle. Metric: lua_num_evaluators

Time Spent In Lua

Number of microseconds the Lua interpreters were running. Metric: lua_time_spent

Router Latencies

Histogram-like graph showing how many responses were sent within the given latency interval. Metric: orc_latency_bucket

Internal debugging

A folder that contains dashboards intended for internal use.

ACD: Incoming Internet Connections dashboard

SSL Warnings

Rate of warnings logged during TLS connections Metric: num_ssl_warnings_total

SSL Errors

Rate of errors logged during TLS connections Metric: num_ssl_errors_total

Valid Internet HTTPS Requests

Rate of incoming requests that were deemed valid, HTTPS only. Metric: num_valid_http_requests

Invalid Internet HTTPS Requests

Rate of incoming requests that were deemed invalid, HTTPS only. Metric: num_invalid_http_requests

Valid Internet HTTP Requests

Rate of incoming requests that were deemed valid, HTTP only. Metric: num_valid_http_requests

Invalid Internet HTTP Requests

Rate of incoming requests that were deemed invalid, HTTP only. Metric: num_invalid_http_requests

Prometheus: ACD dashboard

Logged Warnings

Rate of logged warnings since the router has started, divided into CDN-related and CDN-unrelated. Metric: num_log_warnings_total

Logged Errors

Rate of logged errors since the router has started. Metric: num_log_errors_total

HTTP Requests

Rate of responses sent to incoming connections. Metric: orc_latency_count

Number Of Active Sessions

Number of sessions opened on router that are still active. Metric: num_sessions

Total Number Of Sessions

Total number of sessions opened on router. Metric: num_sessions

Session Type Counts (Non-Stacked)

Number of active sessions divided by type; see metric documentation linked below for up-to-date list of types. Metric: num_sessions

Prometheus/ACD: Subrunners

Client Connections

Number of currently open client connections per subrunner. Metric: subrunner_client_conns

Asynchronous Queues (Current)

Number of queued events per subrunner, roughly corresponding to load. Metric: subrunner_async_queue

Used <Send/receive> Data Blocks

Number of send or receive data blocks currently in use per subrunner, as decided by the “Send/receive” drop down box. Metric: subrunner_used_send_data_blocks and subrunner_used_receive_data_blocks

Asynchronous Queues (Max)

Maximum number of events waiting in queue. Metric: subrunner_max_async_queue

Total <Send/receive> Data Blocks

Number of send or receive data blocks allocated per subrunner, as decided by the “Send/receive” drop down box. Metric: subrunner_total_send_data_blocks and subrunner_total_receive_data_blocks

Low Queue (Current)

Number of low priority events queued per subrunner. Metric: subrunner_low_queue

Medium Queue (Current)

Number of medium priority events queued per subrunner. Metric: subrunner_medium_queue

High Queue (Current)

Number of high priority events queued per subrunner. Metric: subrunner_high_queue

Low Queue (Max)

Maximum number of events waiting in low priority queue. Metric: subrunner_max_low_queue

Medium Queue (Max)

Maximum number of events waiting in medium priority queue. Metric: subrunner_max_medium_queue

High Queue (Max)

Maximum number of events waiting in high priority queue. Metric: subrunner_max_high_queue

Wakeups

The number of times a subrunner has been waken up from sleep. Metric: subrunner_io_wakeups

Overloaded

The number of times the number of queued events for a subrunner exceeded its maximum. Metric: subrunner_times_worker_overloaded

Autopause

Number of sockets that have been automatically paused. This happens when the work manager is under heavy load. Metric: subrunner_io_autopause_sockets

8.4 - Alarms and Alerting

Configuring alarms and alerting

Alerts are generated by the third-party service Prometheus, which sends them to the Alertmanager service. A default containerized instance of Alertmanager is deployed alongside ESB3024 Router. Out of the box, Alertmanager ships with only a sample configuration file, and will require manual configuration prior to enabling the alerting functionality. Due to the many different possible configurations for how alerts are both detected and where they are pushed, the official Alertmanager documentation should be followed for how to configure the service.

The router ships with Alertmanager 0.25, the documentation for which can be found at prometheus.io. The Alertmanager configuration file can be found on the host at /opt/edgeware/acd/alertmanager/alertmanager.yml.

Accessing Alertmanager

Alertmanager has a web interface that is listening for HTTP connections on port 9093. There is no authentication, so anyone who has access to the host that is running Alertmanager can access the interface.

Starting / Stopping Alertmanager

After the service is configured, it can be managed via systemd, under the service unit acd-alertmanager.

systemctl start acd-alertmanager

Logging

The container logs are automatically published to the system journal, under the same unit descriptor, and can be viewed using journalctl

journalctl -u acd-alertmanager

8.5 - Monitoring multiple routers

By default an instance of Prometheus only monitors the ESB3024 Router that is installed on the same host as where Prometheus is installed. It is possible to make it monitor other router instances and visualize all instances on one Grafana instance.

Configuring of Prometheus

This is configured in the scraping configuration of Prometheus, which is found in the file /opt/edgeware/acd/prometheus/prometheus.yaml, which typically looks like this:

global:
  scrape_interval:     15s

rule_files:
  - recording-rules.yaml

# A scrape configuration for router metrics
scrape_configs:
  - job_name: 'router-scraper'
    scheme: https
    tls_config:
      insecure_skip_verify: true
    static_configs:
    - targets:
      - acd-router-1:5001
    metrics_path: /m1/v1/metrics
    honor_timestamps: true
  - job_name: 'edns-proxy-scraper'
    scheme: http
    static_configs:
    - targets:
      - acd-router-1:8888
    metrics_path: /metrics
    honor_timestamps: true

More routers can be added to the scrape configuration by simply adding more routers under targets in the scraper jobs.

For instance, to monitor acd-router-2 and acd-router-3 along acd-router-1, the configuration file needs to be modified like this:

global:
  scrape_interval:     15s

rule_files:
  - recording-rules.yaml

# A scrape configuration for router metrics
scrape_configs:
  - job_name: 'router-scraper'
    scheme: https
    tls_config:
      insecure_skip_verify: true
    static_configs:
    - targets:
      - acd-router-1:5001
      - acd-router-2:5001
      - acd-router-3:5001
    metrics_path: /m1/v1/metrics
    honor_timestamps: true
  - job_name: 'edns-proxy-scraper'
    scheme: http
    static_configs:
    - targets:
      - acd-router-1:8888
      - acd-router-2:8888
      - acd-router-3:8888
    metrics_path: /metrics
    honor_timestamps: true

After the file has been modified, Prometheus needs to be restarted by typing

systemctl restart acd-prometheus

It is possible to use the same configuration on multiple routers, so that all routers in a deployment can monitor each other.

Selecting router in Grafana

In the top left corner the Grafana dashboards have a drop-down menu labeled “ACD Router”, which allows to choose which router to monitor.

8.6 - Routing Rule Evaluation Metrics

Node Visit counters

ESB3024 Router counts the number of times a node and any of its children is selected in the routing table.

The visit counters can be retrieved with the following end points:

`/v1/node_visits`

Returns visit counters for each node as a flat list of host:counter pairs in JSON.

Example output:

{
  "node1": "1",
  "node2": "1",
  "node3": "1",
  "top": "3"
}

`/v1/node_visits_graph`

Returns a full graph of nodes with their respective visit counters in GraphML.

Example output:

<?xml version="1.0"?>
<graphml xmlns="http://graphml.graphdrawing.org/xmlns"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://graphml.graphdrawing.org/xmlns
http://graphml.graphdrawing.org/xmlns/1.0/graphml.xsd">
  <key id="visits" for="node" attr.name="visits" attr.type="string" />
  <graph id="G" edgedefault="directed">
    <node id="routing_table">
      <data key="visits">5</data>
    </node>
    <node id="cdn1">
      <data key="visits">1</data>
    </node>
    <node id="node1">
      <data key="visits">1</data>
    </node>
    <node id="cdn2">
      <data key="visits">2</data>
    </node>
    <node id="node2">
      <data key="visits">2</data>
    </node>
    <node id="cdn3">
      <data key="visits">2</data>
    </node>
    <node id="node3">
      <data key="visits">2</data>
    </node>
    <edge id="e0" source="cdn1" target="node1" />
    <edge id="e1" source="routing_table" target="cdn1" />
    <edge id="e2" source="cdn2" target="node2" />
    <edge id="e3" source="routing_table" target="cdn2" />
    <edge id="e4" source="cdn3" target="node3" />
    <edge id="e5" source="routing_table" target="cdn3" />
  </graph>
</graphml>

To receive the graph as JSON, specify Accept:application/json in the request headers.

Example output:

{
  "edges": [
    {
      "source": "cdn1",
      "target": "node1"
    },
    {
      "source": "routing_table",
      "target": "cdn1"
    },
    {
      "source": "cdn2",
      "target": "node2"
    },
    {
      "source": "routing_table",
      "target": "cdn2"
    },
    {
      "source": "cdn3",
      "target": "node3"
    },
    {
      "source": "routing_table",
      "target": "cdn3"
    }
  ],
  "nodes": [
    {
      "id": "routing_table",
      "visits": "5"
    },
    {
      "id": "cdn1",
      "visits": "1"
    },
    {
      "id": "node1",
      "visits": "1"
    },
    {
      "id": "cdn2",
      "visits": "2"
    },
    {
      "id": "node2",
      "visits": "2"
    },
    {
      "id": "cdn3",
      "visits": "2"
    },
    {
      "id": "node3",
      "visits": "2"
    }
  ]
}

Resetting Visit Counters

A node visit counter with an id not matching any node id of a newly applied routing table is destroyed.

Reset all counters to zero by momentarily applying a configuration with a placeholder routing root node, that has unique id and an empty members list, e.g:

"routing": {
  "id": "empty_routing_table",
  "members": []
}

… and immediately reapply the desired configuration.

8.7 - Metrics

Metrics endpoint

ESB3024 Router collects a large number of metrics that can give insight into it’s condition at runtime. Those metrics are available in Prometheus’ text-based exposition format at endpoint :5001/m1/v1/metrics.

Below is the description of these metrics along with their labels.

`client_response_status`

Number of responses sent back to incoming requests.

Type: counter

`lua_num_errors`

Number of errors encountered when evaluating Lua rules.

Type: counter

`lua_num_evaluators`

Number of Lua rules evaluators (active interpreters).

Type: gauge

`lua_time_spent`

Time spent by running Lua evaluators, in microseconds.

Type: counter

`num_configuration_changes`

Number of times configuration has been changed since the router has started.

Type: counter

`num_endpoint_requests`

Number of requests redirected per CDN endpoint.

Type: counter
Labels:
- endpoint - CDN endpoint address.
- selector - whether the request was counted during initial or instream selection.

`num_invalid_http_requests`

Number of client requests that either use wrong method or wrong URL path. Also number of all requests that cannot be parsed as HTTP.

Type: counter
Labels:
- source - name of internal filter function that classified request as invalid. Probably not of much use outside debugging.
- type - whether the request was HTTP (Unencrypted) or HTTPS (SSL).

`num_log_errors_total`

Number of logged errors since the router has started.

Type: counter

`num_log_warnings_total`

Number of logged warnings since the router has started.

Type: counter

`num_managed_redirects`

Number of redirects to the router itself, which allows session management.

Type: counter

`num_manifests`

Number of cached manifests.

Type: gauge
Labels:
- count - state of manifest in cache, can be either lru, evicted or total.

`num_qoe_losses`

Number of “lost” QoE decisions per CDN.

Type: counter
Labels:
- cdn_id - ID of CDN that loose QoE battle.
- cdn_name - name of CDN that loose QoE battle.
- selector - whether the decision was taken during initial or instream selection.

`num_qoe_wins`

Number of “won” QoE decisions per CDN.

Type: counter
Labels:
- cdn_id - ID of CDN that won QoE battle.
- cdn_name - name of CDN that won QoE battle.
- selector - whether the decision was taken during initial or instream selection.

`num_rejected_requests`

Deprecated, should always be at 0.

Type: counter
Labels:
- selector - whether the request was counted during initial or instream selection.

`num_requests`

Total number of requests received by the router.

Type: counter
Labels:
- selector - whether the request was counted during initial or instream selection.

`num_sessions`

Number of sessions opened on router.

Type: gauge
Labels:
- state - either active or inactive.
- type - one of: initial, instream, qoe_on, qoe_off, qoe_agent or sp_agent.

`num_ssl_errors_total`

Number of all errors logged during TLS connections, both incoming and outgoing.

Type: counter

`num_ssl_warnings_total`

Number of all warnings logged during TLS connections, both incoming and outgoing.

Type: counter
Labels:
- category - which kind of TLS connection triggered the warning. Can be one of: cdn, content, generic, repeated_session or empty.

`num_unhandled_requests`

Number of requests for which no CDN could be found.

Type: counter
Labels:
- selector - whether the request was counted during initial or instream selection.

`num_unmanaged_redirects`

Number of redirects to “outside” the router - usually to CDN.

Type: counter
Labels:
- cdn_id - ID of CDN picked for redirection.
- cdn_name - name of CDN picked for redirection.
- selector - whether the redirect was result of initial or instream selection.

`num_valid_http_requests`

Number of received requests that were not deemed invalid, see num_invalid_http_requests.

Type: counter
Labels:
- source - name of internal filter function that classified request as invalid. Probably not of much use outside debugging.
- type - whether the request was HTTP (Unencrypted) or HTTPS (SSL).

`orc_latency_bucket`

Total number of responses sorted into “latency buckets” - labels denoting latency interval.

Type: counter
Labels:
- le - latency bucket that given response falls into.
- orc_status_code - HTTP status code of given response.

`orc_latency_count`

Total number of responses.

Type: counter
Labels:
- tls - whether the response was sent via SSL/TLS connection or not.
- orc_status_code - HTTP status code of given response.

`ssl_certificate_days_remaining`

Number of days until a SSL certificate expires.

Type: gauge
Labels:
- domain - the common name of the domain that the certificate authenticates.
- not_valid_after - the expiry time of the certificate.
- not_valid_before - when the certificate starts being valid.
- usable - if the certificate is usable to the router, see the ssl_certificate_usable_count metric for an explanation.

`ssl_certificate_usable_count`

Number of usable SSL certificates. A certificate is usable if it is valid and authenticates a domain name that points to the router.

Type: gauge

8.7.1 - Internal Metrics

Internal Metrics

A subrunner is an internal module of ESB3024 Router which handles routing requests. The subrunner metrics are technical and mainly of interest for Agile Content. These metrics will be briefly described here.

`subrunner_async_queue`

Number of queued events per subrunner, roughly corresponding to load.

Type: gauge
Labels:
- subrunner_id - ID of given subrunner.

`subrunner_client_conns`

Number of currently open client connections per subrunner.

Type: gauge
Labels:
- subrunner_id - ID of given subrunner.

`subrunner_high_queue`

Number of high priority events queued per subrunner.

Type: gauge
Labels:
- subrunner_id - ID of given subrunner.

`subrunner_io_autopause_sockets`

Number of sockets that have been automatically paused. This happens when the work manager is under heavy load.

Type: counter
Labels:
- subrunner_id - ID of given subrunner.

`subrunner_io_send_data_fast_attempts`

A fast data path was added that in many cases increases the performance of the router. This metric was added to verify that the fast data path is taken.

Type: counter
Labels:
- subrunner_id - ID of given subrunner.

`subrunner_io_wakeups`

The number of times a subrunner has been waken up from sleep.

Type: counter
Labels:
- subrunner_id - ID of given subrunner.

`subrunner_low_queue`

Number of low priority events queued per subrunner.

Type: gauge
Labels:
- subrunner_id - ID of given subrunner.

`subrunner_max_async_queue`

Maximum number of events waiting in queue.

Type: gauge
Labels:
- subrunner_id - ID of given subrunner.

`subrunner_max_high_queue`

Maximum number of events waiting in high priority queue.

Type: gauge
Labels:
- subrunner_id - ID of given subrunner.

`subrunner_max_low_queue`

Maximum number of events waiting in low priority queue.

Type: gauge
Labels:
- subrunner_id - ID of given subrunner.

`subrunner_max_medium_queue`

Maximum number of events waiting in medium priority queue.

Type: gauge
Labels:
- subrunner_id - ID of given subrunner.

`subrunner_medium_queue`

Number of medium priority events queued per subrunner.

Type: gauge
Labels:
- subrunner_id - ID of given subrunner.

`subrunner_times_worker_overloaded`

Number of times when queued events for given subrunner exceeded the tuning.overload_threshold value (defaults to 32).

Type: counter
Labels:
- subrunner_id - ID of given subrunner.

`subrunner_total_receive_data_blocks`

Number of receive data blocks allocated per subrunner.

Type: gauge
Labels:
- subrunner_id - ID of given subrunner.

`subrunner_total_send_data_blocks`

Number of send data blocks allocated per subrunner.

Type: gauge
Labels:
- subrunner_id - ID of given subrunner.

`subrunner_used_receive_data_blocks`

Number of receive data blocks currently in use per subrunner. Same as subrunner_total_receive_data_blocks.

Type: gauge
Labels:
- subrunner_id - ID of given subrunner.

`subrunner_used_send_data_blocks`

Number of send data blocks currently in use per subrunner. Same as subrunner_total_send_data_blocks.

Type: gauge
Labels:
- subrunner_id - ID of given subrunner.

9 - Releases

ESB3024 Router releases

9.1 - Release esb3024-1.14.2

Build date

2024-10-01

Release status

Type: production

Breaking changes

If upgrading from a release prior to 1.10.0, the Director needs to be upgraded to 1.10.0, 1.10.1 or 1.10.2 before installing 1.14.2. See Installing a 1.14 release for more information.
In esb3024-1.14.0, the configuration setting services.routing.settings.allowedProxies has been renamed to services.routing.settings.trustedProxies and has changed default behavior. If empty, proxy connections are now denied by default. See Trusted proxies for more information.
Starting with esb3024-1.14.0, a minimum CPU architecture level of x86-64-v2 is required. See system requirements below for more information.

Change log

NEW: Define custom_capacity_var as a number in host_has_bw_custom(). Using a selection input variable for custom_capacity_var is no longer necessary. [ESB3024-1119]
FIXED: Predictive load balancing functions do not handle missing interface [ESB3024-1100]
FIXED: Client closing socket can cause proxy IP to resolve to “?” [ESB3024-1139]
FIXED: ACD crashes when attempting to read corrupt cached data. The cached data can become corrupt if the filesystem is manipulated by a user or the system runs out of storage. [ESB3024-1147]
FIXED: Subnets are not being persisted to disk [ESB3024-1149]
FIXED: ACD overwrites custom GeoIP MMDB files with the default shipped MMDB files when upgrading [ESB3024-1150]

Deprecations

From esb3024-1.14.0, the grafana-loki and fluentbit containers have been deprecated and are no longer installed with the system. Previously installed containers may be manually stopped and removed if not used, but they will not be uninstalled automatically.

System Requirements

Starting with esb3024-1.14.0 the ACD Router now requires a minimum CPU architecture level of x86-64-v2 due to inclusion of Oracle Linux 9 inside the container. While all modern CPUs support this archetecture level, virtual hypervisors may default to a CPU type that has more compatibility with older processors. If this minimum CPU architecture level is not attained the containers may refuse to start. See Operating System Compatibility and Building Red Hat Enterprise Linux 9 for the x86-64-v2 Microarchitecture Level for more information.

Known Limitations

The GUI is not working for this release.
The Telegraf metrics agent might not be able to read all relevant network interface data on some releases of ESB2001. The predictive load balancing function host_has_bw() and the health check function interfaces_online() might therefore not work as expected.
- The recommended workaround for host_has_bw() is to use host_has_bw_custom(), documented in Built-in Lua functions. host_has_bw_custom() accepts a numeric argument for the host’s network interface capacity which can be used if the data supplied by the Telegraf metrics agents do not contain this information.
- It is not recommended to use interfaces_online() until the issue is resolved on ESB2001.

9.2 - Release esb3024-1.14.0

Build date

2024-09-03

Release status

Type: production

Breaking changes

If upgrading from a release prior to 1.10.0, the Director needs to be upgraded to 1.10.0, 1.10.1 or 1.10.2 before installing 1.14.0. See Installing an 1.14 release for more information.
In esb3024-1.14.0, the configuration setting services.routing.settings.allowedProxies has been renamed to services.routing.settings.trustedProxies and has changed default behavior. If empty, proxy connections are now denied by default. See Trusted proxies for more information.
Starting with esb3024-1.14.0, a minimum CPU architecture level of x86-64-v2 is required. See system requirements below for more information.

Change log

NEW: Remove grafana-loki and fluentbit containers [ESB3024-774]
NEW: Extend num_endpoint_requests metric with host ID [ESB3024-975]
NEW: Improved subnets endpoint. See API overview documentation for details. [ESB3024-1018]
NEW: Support RHEL-9 / OL9 [ESB3024-1022]
NEW: Support OpenSSL 3 [ESB3024-1025]
NEW: Changed the router base image to oracle linux 9. See breaking changes [ESB3024-1034]
NEW: Rename allowedProxies to trustedProxies [ESB3024-1085]
NEW: Deny proxy connections by default if trustedProxies is empty [ESB3024-1088]
FIXED: Too long classifier name crashes confd-transformer [ESB3024-949]
FIXED: Lua condition si() doesn’t handle boolean values [ESB3024-1017]
FIXED: Classifiers of type stringMatcher and regexMatcher can’t use content query params as source [ESB3024-1032]
FIXED: ConsistentHashing algorithm is not content aware [ESB3024-1053]
FIXED: Large configurations fail to apply. The REST API max body size is now configurable. [ESB3024-1056]
FIXED: Convoy-bridge DB connection failure spams logs [ESB3024-1080]
FIXED: Convoy-bridge does not send correctly formatted session-id [ESB3024-1081]
FIXED: Response translation removes message body [ESB3024-1082]

Deprecations

From esb3024-1.14.0, the grafana-loki and fluentbit containers have been deprecated and are no longer installed with the system. During upgrade these containers may manually be stopped and removed if not used.

System Requirements

Starting with esb3024-1.14.0 the ACD-Router now requires a minimum CPU architecture level of x86-64-v2 due to inclusion of Oracle Linux 9 inside the container. While all modern CPUs support this archetecture level, virtual hypervisors may default to a CPU type that has more compatibility with older processors. If this minimum CPU architecture level is not attained the containers may refuse to start. See Operating System Compatibility and Building Red Hat Enterprise Linux 9 for the x86-64-v2 Microarchitecture Level for more information.

Known Limitations

The GUI is not working for this release.
The Telegraf metrics agent might not be able to read all relevant network interface data on some releases of ESB2001. The predictive load balancing function host_has_bw() and the health check function interfaces_online() might therefore not work as expected.
- The recommended workaround for host_has_bw() is to use host_has_bw_custom(), documented in Built-in Lua functions. A manual integration of setting a custom selection input variable representing the network interface capacity and using this in host_has_bw_custom() is necessary. See API Overview for details on using the selection input API. to use host_has_bw_custom()
- The recommended workaround for interfaces_online() is to not use the function until the issue is resolved.

9.3 - Release esb3024-1.12.1

Build date

2024-07-03

Release status

Type: production

Breaking changes

If upgrading from a release prior to 1.10.0, the Director needs to be upgraded to 1.10.0, 1.10.1 or 1.10.2 before installing 1.12.1. See Installing an 1.12 release for more information.

Change log

NEW: Remove support for EL7 [ESB3024-1046]
FIXED: Large configuration causes crash [ESB3024-1043]

Known Limitations

The GUI is not working for this release.

9.4 - Release esb3024-1.12.0

Build date

2024-06-19

Release status

Type: production

Breaking changes

If upgrading from a release prior to 1.10.0, the Director needs to be upgraded to 1.10.0, 1.10.1 or 1.10.2 before installing 1.12.0. See Installing release 1.12.0 for more information.

Change log

NEW: Move managed session creation to Lua. Creating managed sessions is now handled by using the session translation function. [ESB3024-454]
NEW: Grafana dashboards to monitor Quality [ESB3024-511]
NEW: Measure and expose quality scores. A quality score per host and session group is now available when making routing decisions. [ESB3024-512]
NEW: Add default session classifiers. When resetting the list of classifiers in confd, it is now populated with commonly used classifers. [ESB3024-769]
NEW: Add configuration migration tool [ESB3024-824]
NEW: Add new Random classifier [ESB3024-899]
NEW: Add URL parsing code to Lua library. An URL parser based on https://github.com/golgote/neturl/ with extensions for path splitting and joining [ESB3024-936]
NEW: Standard library Lua functions now use the same log mechanism as the Director [ESB3024-966]
NEW: Extend ’num_sessions’ metric to include a label with the selected host [ESB3024-973]
NEW: Add quality level metrics [ESB3024-974]
NEW: Add host request translation function [ESB3024-996]
FIXED: ConsistentHashing Algorithm only supports MD5. MD5, SDBM and Murmur are now supported. [ESB3024-929]
FIXED: Confd IPv4 validation rejects IPs with /29 netmask [ESB3024-1010]
FIXED: Stale timestamped selection input not being pruned. Added configurable timestamped selection input timeout limit. [ESB3024-1016]

Known Limitations

The GUI is not working for this release.

9.5 - Release esb3024-1.10.2

Build date

2024-06-03

Release status

Type: production

Breaking changes

If upgrading from a release prior to 1.10.0, the configuration needs to be manually updated after upgrading to 1.10.2. See Installing release 1.10.x for more information.

Change log

FIXED: ConsistentHashing rule broken [ESB3024-969]
FIXED: Increase configuration size limit [ESB3024-983]

Known Limitations

None

9.6 - Release esb3024-1.10.1

Build date

2024-04-18

Release status

Type: production

Breaking changes

If upgrading from a release prior to 1.10.0, the configuration needs to be manually updated after upgrading to 1.10.1. See Installing release 1.10.x for more information.

Change log

NEW: Change predictive load balancing functions to use megabits/s [ESB3024-932]
FIXED: Logic classifier statements can consume all memory [ESB3024-937]

Known Limitations

None

9.7 - Release esb3024-1.10.0

Build date

2024-04-02

Release status

Type: production

Breaking changes

The configuration needs to be manually updated after upgrading to 1.10.0. See Installing release 1.10.0 for more information.

Change log

NEW: Use metrics from streamers in routing decisions. Added standard library Lua support to use hardware metrics in routing decisions. Added host health checks in the configuration. [ESB3024-154]
NEW: Remove unused field “apiKey” from configuration [ESB3024-426]
NEW: Support integration with Convoy Analytics [ESB3024-694]
NEW: Support combining classifiers using AND/OR in session groups [ESB3024-776]
NEW: Enable access logging by default [ESB3024-816]
NEW: Improved Lua translation function error handling [ESB3024-874]
NEW: Updated predictive load balancing functions to support hardware metrics [ESB3024-887]
NEW: Remove apiKey from documentation [ESB3024-927]
FIXED: Condition with ‘or’ statement sometimes generate faulty Lua [ESB3024-863]

Known Limitations

None

9.8 - Release esb3024-1.8.0

Build date

2024-02-07

Release status

Type: production

Breaking changes

The configuration needs to be manually updated after upgrading to 1.8.0. See Installing release 1.8.0 for more information.

Change log

NEW: Remove ESB3026 Account Monitor from installer. [ESB3024-354]
NEW: Improve selection input endpoint flexibility and security. See API overview documentation for details. [ESB3024-423]
NEW: Support anonymous geoip rules [ESB3024-699]
NEW: Add ASN IDs list classifiers to confd [ESB3024-778]
NEW: Enable content popularity tracking by default. Added option to enable/disable in confd/confcli. [ESB3024-781]
NEW: Remove dependency on session from security token verification [ESB3024-809]
FIXED: A lot of JSON output on failed routing. HTTP response no longer contains internal routing information. [ESB3024-523]
FIXED: Returning Lua table from Lua debug endpoint can crash router. Selection Input values now support floating point values in a Lua context [ESB3024-691]
FIXED: Floating point selection inputs are truncated to ints when passed to Lua context [ESB3024-710]
FIXED: Race condition between RestApi and Session [ESB3024-753]
FIXED: confd/concli doesn’t support “forward_host_header” on hostGroups [ESB3024-761]
FIXED: Support Lua vector keys in reverse order [ESB3024-780]

Known Limitations

None

9.9 - Release esb3024-1.6.0

Build date

2023-12-20

Release status

Type: production

Breaking changes

The configuration needs to be manually updated after upgrading to 1.6.0. See configuration changes between 1.4.0 and 1.6.0 for more information.

Change log

NEW: Remove the lua_paths array from the config . Lua scripts are now added using a REST API on the /v1/lua/ endpoint. [ESB3024-204]
NEW: Separate “account-monitor” from installer [ESB3024-238]
NEW: Consistent hashing based routing . Added support for content distribution control for load balancing and cache partitioning [ESB3024-274]
NEW: Predictive load balancing . Account for in-transit traffic to prevent cache overload when there is a sudden burst of new sessions. [ESB3024-275]
NEW: Support Convoy security tokens [ESB3024-386]
NEW: Expose quality, host and session ID in the session object in Lua context [ESB3024-429]
NEW: Support upgrade of system python in installer [ESB3024-442]
NEW: Do not configure selinux and firewalld in installer [ESB3024-493]
NEW: Convoy Distribution/Account integration [ESB3024-503]
NEW: Make eDNS server port configurable . The router configuration hosts.proxy_address has been renamed to hosts.proxy_url and now accepts a port that is used when connecting to the proxy. The cdns.http_port and cdns.https_port configurations now configure the port that is used for connecting to the EDNS server, before they configured the port that was used for connecting to the proxy. [ESB3024-509]
NEW: Expand node table in Lua context . New fields are: node.id, node.visits, host.id, host.recent_selections [ESB3024-630]
FIXED: DNS lookup can fail . DNS lookup can fail when same content requested from both IPv4 and IPv6 clients [ESB3024-427]
FIXED: Failed DNS requests are not retried . Fixed bug where failed eDNS requests were not retried [ESB3024-504]
FIXED: Lua functions are not updated when uploaded [ESB3024-544]
FIXED: Undefined metatable fields evaluate to false rather than nil [ESB3024-642]
FIXED: Evaluator::evaluate() doesn’t support different types of its variadic arguments [ESB3024-687]
FIXED: Segfault when accessing REST api with empty path [ESB3024-752]
FIXED: Container UID/GID may change between versions [ESB3024-755]

9.10 - Release esb3024-1.4.0

Build date

2023-09-29

Release status

Type: production

Breaking changes

All configuration is now stored under /opt/edgeware/acd, see [ESB3024-425]. Any configuration that is to be kept needs to be manually migrated.
Typically /opt/edgeware/etc/confd/store/store.json needs to be copied to /opt/edgeware/acd/confd/store/store.json, /opt/edgeware/var/lib/acd-router/cached-acd-router-config.json needs to be copied to /opt/edgeware/acd/router/cache/config.json and /opt/edgeware/var/lib/acd-router/cached-router-rest-api-key.json needs to be copied to /opt/edgeware/acd/router/cache/rest-api-key.json. Custom Lua functions need to be migrated from /opt/edgeware/acd/var/lib/custom_lua to /opt/edgeware/acd/router/lib/custom_lua. The Prometheus and Grafana configurations also need to be copied if they have been modified.

The following changes were made to the confcli configuration [ESB3024-455].
The rule fields inside the routing rule items were renamed to condition to avoid confusion with the rules list. This applies to the blocks allow, deny, split and weighted.
The popularityThreshold in the contentPopularity routing rule was renamed to contentPopularityCutoff.

Change log

NEW: 1-Page Status Report . Added command ew-sysinfo that can be used on any machine with an ESB3024 installation. The command outputs various information about the system and installed services which can be used for monitoring and diagnostics. [ESB3024-391]
NEW: Update routing rule property names . Routing rule property names updated for consistency and clarity [ESB3024-455]
FIXED: Deleting confd API array element inside oneOf object fails [ESB3024-355]
FIXED: Container logging not captured by systemd until services are restarted [ESB3024-359]
FIXED: Alertmanager restricts the configuration to a single file [ESB3024-381]
FIXED: Split rules in routing configuration should terminate on error [ESB3024-420]
FIXED: Improve alert configuration in Prometheus [ESB3024-422]
FIXED: Inconsistent storage paths of service configuration and data [ESB3024-425]
FIXED: confd-transformer is not working in el7 [ESB3024-430]

9.11 - Release acd-router-1.2.3

Build date

2023-08-16

Release status

Type: production

Breaking changes

None

Change log

NEW: Add more classifiers . New classifiers are hostName, contentUrlPath, userAgent, contentUrlQueryParameters [ESB3024-298]
NEW: Add allow- and denylist rule blocks [ESB3024-380]
NEW: Add enhanced validation of scriptable field in routing rules [ESB3024-393]
NEW: Add services to the config tree [ESB3024-410]
NEW: Prohibit unknown configuration properties [ESB3024-416]
FIXED: Duplicate session group IDs are allowed [ESB3024-49]
FIXED: Invalid URL returned for IPv4 requests when using a DNS backend [ESB3024-374]
FIXED: Not possible to set log level in eDNS proxy [ESB3024-378]
FIXED: Instream selection fails when DASH manifest has template paths using “../” [ESB3024-384]

9.12 - Release acd-router-1.2.0

Build date

2023-06-27

Release status

Type: production

Breaking changes

None

Change log

NEW: Add meta fields to the configuration . The API now allows the meta data fields “created_at”, “source” and “source_checksum” that can be used for the API consumer to track who did what change when.
NEW: Control routing behavior based on backend response code . This gives control over when to return backend response codes to the end user and when to trigger a failover to another CDN or host.
NEW: Manage Lua scripts via API
NEW: Support popularity-based routing . Content can be ordered in multiple groups with descending popularity. Popularity can also be tracked per session group.
NEW: Improved support for IPv6 routing . It is now possible to select backend depending on the IP protocol version.
NEW: Add DNS backend support . This allows delegating routing decisions to an EDNS0 server.
NEW: Support HMAC with SHA256 in Lua scripts
NEW: Add alarm support . The alarms are handled by Prometheus and Alertmanager.
NEW: Support saving Grafana Dashboards
NEW: Add simplified configuration API and CLI tool . A new configuration API with an easier to use model has been added. The “confcli” tool present in many other Edgeware products is now supported.
NEW: Add authentication to the REST API
FIXED: Host headers not forwarded to Request Router when ‘redirecting: true’ is enabled
FIXED: IP range classifier 0.0.0.0/0 does not work in session groups

9.13 - Release acd-router-1.0.0

First production

Build date

2022-11-22

Release status

Type: First production release

Known Limitations

The setting “allowed_clients” should not be used since the functionality does not work as expected.

Change log

Flexible routing rule engine with support for Lua plugins. Support many use cases, including CDN Offload and CDN Selection.
Advanced client classification mechanisms for routing based on group memberships (device type, content type, etc).
Geobased routing including dedicated high-performing API for subnet matching, associating an incoming request with a region.
Integration API to feed the service with arbitrary variables to use for routing decisions. Can be used to get streaming bitrate in public CDNs, status from network probes, etc.
Flexible request/response translation manipulation on the client facing interface. Can be used for URL manipulation, encoding/decoding tokens or adapting the interface to e.g. the PowerDNS backend protocol.
Metrics API that can be monitored with standard monitoring software. Out-of-the-box integration with Prometheus and Grafana.
Robust deployment with each service instance running independently, and allowing the service to stay in operational state even when backends become temporarily unavailable.
RHEL 7/8 support.
Online documentation at https://docs.agilecontent.com/

10 - Glossary

ESB3024 Router definitions of commonly used terms

ACD: Agile CDN Director. See “Director”.
Confd: A backend service that hosts the service configuration. Comes with an API, a CLI and a GUI.
Classifier: A filter that associate a request with a tag that can be used to define session groups.
Director: The Agile Delivery OTT router and related services.
ESB: A software bundle that can be separately installed and upgraded, and is released as one entity with one change log. Each ESB is identified with a number. Over time, features and functions within an ESB can change.
Lua: A widely available scripting language that is often used to extend the capabilities of a piece of software.
Router: Unless otherwise specified, an HTTP router that manages an OTT session using HTTP redirect. There are also ways to use DNS instead of HTTP.
Selection Input API: Data posted to this API can be accessed by the routing rules and hence influence the routing decisions.
Subnet API: An API to define mappings between subnets and names (typically regions) for those subnets. Routing rules can then refer to the names rather than the subnets.
Session Group: A handle on a group of requests, defined via classifiers.

ESB3024 Router

1 - Getting Started

Requirements

Hardware

Operating System Compatibility

Firewall Recommendations

Installation

Operations

Configuration Process

API Key Management

Configuration Basics

Integration with Convoy

Additional Resources

Ready for Production

2 - Installation

2.1 - Installing a 1.14 release

Upgrade from and earlier ESB3024 Router release

Troubleshooting

2.1.1 - Configuration changes between 1.12.1 and 1.14

Confd configuration changes

Renamed services.routing.settings.allowedProxies

Added services.routing.tuning.general.restApiMaxBodySize

2.2 - Installing a 1.12 release

Upgrade from ESB3024 Router release 1.10

Troubleshooting

2.2.1 - Configuration changes between 1.10.2 and 1.12

Confd configuration changes

Added services.routing.translationFunctions.hostRequest

Added services.routing.translationFunctions.session

Removed services.routing.settins.managedSessions configuration

Added services.routing.tuning.general.maxActiveManagedSessions tuning parameter.

2.3 - Installing release 1.10.x

Upgrade from ESB3024 Router release 1.8.0

Troubleshooting

2.3.1 - Configuration changes between 1.8.0 and 1.10.x

Confd configuration changes

Added integration.convoy section

Removed services.routing.apiKey configuration

Added services.routing.settings.qoeTracking

Added healthChecks sections to the hosts

Added hashAlgorithm to the consistentHashing rule

2.4 - Installing release 1.8.0

Upgrade

Troubleshooting

2.4.1 - Configuration changes between 1.6.0 and 1.8.0

Confd configuration changes

Added enabled to contentPopularity

Added selectionInputItemLimit to tuning

Added forwardHostHeader to hostGroups

REST API configuration changes

2.5 - Installing release 1.6.0

Upgrade

Troubleshooting

2.5.1 - Configuration changes between 1.4.0 and 1.6.0

confd configuration

Configuration changes

Added translationFunctions block

Renamed sessionGroupIds to sessionGroupNames

Added managedSessions block

Added recentDurationMilliseconds

Storing the updated configuration

Raw configuration

Simple changes

EDNS proxy changes

3 - Firewall

Additional Ports

Convoy bridge integration

4 - API Overview

Raw configuration – /v2/configuration

Validate Configuration – /v2/validate_configuration

Example request

Selection Input – /v1/selection_input

Example successful request (PUT)

Example unsuccessful request (PUT)

Example successful request (GET)

Example successful specific value request (GET)

Example successful request (DELETE)

Example successful specific value request (DELETE)

Example unsuccessful request (DELETE)

Subnets – /v1/subnets

Renamed `services.routing.settings.allowedProxies`

Added `services.routing.tuning.general.restApiMaxBodySize`

Added `services.routing.translationFunctions.hostRequest`

Added `services.routing.translationFunctions.session`

Removed `services.routing.settins.managedSessions` configuration

Added `services.routing.tuning.general.maxActiveManagedSessions` tuning parameter.

Added `integration.convoy` section

Removed `services.routing.apiKey` configuration

Added `services.routing.settings.qoeTracking`

Added `healthChecks` sections to the hosts

Added `hashAlgorithm` to the `consistentHashing` rule

Added `enabled` to `contentPopularity`

Added `selectionInputItemLimit` to `tuning`

Added `forwardHostHeader` to `hostGroups`

Added `translationFunctions` block

Renamed `sessionGroupIds` to `sessionGroupNames`

Added `managedSessions` block

Added `recentDurationMilliseconds`

Raw configuration – `/v2/configuration`

Validate Configuration – `/v2/validate_configuration`

Selection Input – `/v1/selection_input`

Example successful request (`PUT`)

Example unsuccessful request (`PUT`)

Example successful request (`GET`)

Example successful specific value request (`GET`)

Example successful request (`DELETE`)

Example successful specific value request (`DELETE`)

Example unsuccessful request (`DELETE`)

Subnets – `/v1/subnets`

Subrunner Resource Usage – `/v1/usage`

Metrics – `/m1/v1/metrics`

Node Visit Counters – `/v1/node_visits`

Node Visit Graph – `/v1/node_visits_graph`

Session list - `/v1/sessions`

Session details - `/v1/sessions/<id: str>`

Content List - `/v1/content`

Lua scripts – `/v1/lua/<path str>.lua`

Example request (`PUT`)

Example request (`PUT`, from file)

Example request (`GET`)

Example request (`DELETE`)

List Lua scripts – `/v1/lua`

Debug a Lua expression – `/v1/lua/debug`