Configuring dynamic bursting to the Google Cloud Platform (GCP)

Pexip Infinity deployments can burst into the Google Cloud Platform (GCP) cloud when primary conferencing capabilities are reaching their capacity limits, thus providing additional temporary Conferencing Node resources.

This provides the ability to dynamically expand conferencing capacity whenever scheduled or unplanned usage requires it. The GCP cloud Conferencing Nodes instances are only started up when required and are automatically stopped again when capacity demand normalizes, ensuring that GCP costs are minimized.

For complete information about dynamic bursting, see Dynamic bursting to a cloud service.

Configuring your system for dynamic bursting to GCP

These instructions assume that you already have a working Pexip Infinity platform, including one or more primary (always on) Conferencing Nodes in one or more system locations. These existing Conferencing Nodes can be deployed using whichever platform or hypervisor you prefer.

Firewall addresses/ports required for access to the GCP APIs for cloud bursting

Access to the GCP APIs for cloud bursting is only required from the Management Node.

The Management Node connects to www.googleapis.com over HTTPS port 443.

Setting up your bursting nodes in GCP and enabling bursting in Pexip Infinity

You must deploy in GCP the Conferencing Nodes that you want to use for dynamic bursting, and then configure those nodes in Pexip Infinity as the overflow destination for your primary (always on) Conferencing Nodes:

  1. In Pexip Infinity, configure a new "overflow" system location e.g. "GCP burst", that will contain your bursting Conferencing Nodes.

    (Note that system locations are not explicitly configured as "primary" or "overflow" locations. Pexip Infinity automatically detects the purpose of the location according to whether it contains Conferencing Nodes that may be used for dynamic bursting.)

  2. In GCP, set up the service account, roles and permissions that the Pexip Infinity Management Node will use to log in to GCP to start and stop the node instances.

    See Configuring a GCP role, permissions and service account for controlling overflow nodes for more information.

  3. Deploy in GCP the Conferencing Nodes that you want to use for dynamic bursting. Deploy these nodes in the same manner as you would for "always on" usage (see Deploying a Conferencing Node in Google Cloud Platform), except:

    1. Apply to each cloud VM node instance to be used for conference bursting a label with a Key of pexip-cloud and an associated Value set to the Tag value that is shown in the Cloud bursting section on the Platform > Global settings page (the Tag value is the hostname of your Management Node).

      This tag indicates which VM nodes will be started and shut down dynamically by your Pexip system.

    2. When adding the Conferencing Node within Pexip Infinity:

      1. Assign the Conferencing Node to the overflow system location (e.g. "GCP burst").
      2. Disable (uncheck) the Enable distributed database setting (this setting should be disabled for any nodes that are not expected to always be available).
    3. After the Conferencing Node has successfully deployed, manually stop the node instance on GCP.
  4. In Pexip Infinity, go to Platform > Global settings, enable cloud bursting and then configure your bursting threshold, minimum lifetime and other appropriate settings for GCP:

    Option Description
    Enable bursting to the cloud Select this option to instruct Pexip Infinity to monitor the system locations and start up / shut down overflow Conferencing Nodes hosted in your cloud service when in need of extra capacity.
    Bursting threshold

    The bursting threshold controls when your dynamic overflow nodes in your cloud service are automatically started up so that they can provide additional conferencing capacity. When the number of additional HD calls that can still be hosted in a location reaches or drops below the threshold, it triggers Pexip Infinity into starting up an overflow node in the overflow location.

    See Configuring the bursting threshold for more information.

    Tag name
    and
    Tag value
    These read-only fields indicate the tag name (always pexip-cloud) and associated tag value (the hostname of your Management Node) that you must assign to each of your cloud VM node instances that are to be used for dynamic bursting.
    Minimum lifetime An overflow cloud bursting node is automatically stopped when it becomes idle (no longer hosting any conferences). However, you can configure the Minimum lifetime for which the bursting node is kept powered on. By default this is set to 50 minutes, which means that a node is never stopped until it has been running for at least 50 minutes. If your service provider charges by the hour, it is more efficient to leave a node running for 50 minutes — even if it is never used — as that capacity can remain on immediate standby for no extra cost. If your service provider charges by the minute you may want to reduce the Minimum lifetime.
    Cloud provider Select GCP.
    GCP private key

    The PEM-formatted private key for the Google Cloud Platform service account that the Pexip Infinity Management Node will use to log in to GCP to start and stop the node instances.

    If you have created and then downloaded a JSON private key file from the GCP service account, open the file in a plain text editor and copy everything between the double quotes following "private_key" : including the -----BEGIN PRIVATE KEY----- and -----END PRIVATE KEY----- header and footer, and then paste it into this field.

    After you have saved the settings, the private key will be stored in an encrypted format and subsequently displayed as asterisks.

    GCP service account ID The Service account ID of the service account you have set up in GCP, for example, bursting@example.com.iam.gserviceaccount.com.
    GCP project ID The ID of the GCP project containing the bursting nodes.
  5. Go to Platform > Locations and configure the system locations that contain your "always on" Conferencing Nodes (the nodes/locations that initially receive calls) so that they will overflow to your new "GCP burst" location when necessary.

    When configuring your "always on" locations, you must set the Primary overflow location to the bursting location containing your overflow nodes. (Automatic bursting, and the stopping and starting of overflow nodes only applies to the Primary overflow location; the Secondary overflow location can only be used for standard overflow i.e. to other "always on" nodes.) You should configure the Transcoding location as normal to the location that will initially handle the call media (before overflow/bursting is required).

    We recommend that you do not mix your "always on" Conferencing Nodes and your bursting nodes in the same system location.

Configuring a GCP role, permissions and service account for controlling overflow nodes

Within GCP you must set up a service account to be used by Pexip Infinity to start up and shut down the Conferencing Node overflow instances.

First, you need to create a GCP role and its associated permissions:

  1. From the GCP project console, go to IAM & admin > Roles.
  2. Select + Create Role.
  3. Configure a Title and ID e.g. "Bursting".
  4. Select + Add Permissions.
  5. From the list of permissions, select compute.instances.list, compute.instances.start, compute.instances.stop and compute.zoneOperations.list.

    These permissions allow the service account to stop and start VM instances.

  6. Select Create.

Next, you need to create a service account and apply the role to the account:

  1. From the GCP project console, go to IAM & admin > Service Accounts.
  2. Select + Create Service Account.
  3. Configure a Service account name e.g. "bursting" and add a Description.

    The Service account ID is automatically created, based on the name you enter, and is what you need to configure in the GCP service account ID field in Pexip Infinity.

  4. Select Create.

  5. For Service account permissions, select the "Bursting" role you created above.
  6. Select Continue.

  7. On the next page you can optionally grant users access to the service account.
  8. Select + Create Key to create a private key for the account.
  9. On the Create key page, select a key type of JSON.
  10. Select Create.

    A JSON file that includes your private key is generated and saved to your local computer.

    Select Close to dismiss the message saying that the private key has been saved to your computer.

  11. Select Done at the bottom of the Create service account page.

You can now use this service account and private key when configuring bursting In Pexip Infinity (Platform > Global settings).

Configuring the bursting threshold

When enabling your platform for cloud bursting the most important decision you must make is the level at which to set the bursting threshold:

  • The bursting threshold controls when your dynamic overflow nodes in your cloud service are automatically started up so that they can provide additional conferencing capacity. When the number of additional HD calls that can still be hosted in a location reaches or drops below the threshold, it triggers Pexip Infinity into starting up an overflow node in the overflow location.

    For example, setting the threshold to 5 means that when there are 5 or fewer HD connections still available in a location, an overflow node will be started up.

  • When an overflow location reaches the bursting threshold i.e. the number of additional HD calls that can still be hosted on the Conferencing Nodes in the overflow location reaches the threshold, another overflow node in that location is started up, and so on.

    Note that the current number of free HD connections in the original location is ignored when deciding if the overflow location needs to overflow further — however, new calls will automatically use any available media resource within those original primary locations that has become available.

  • The bursting threshold is a global setting — it applies to every system location in your deployment.
  • Note that it takes approximately 5 minutes for a dynamic Conferencing Node instance to start up and become available for conference hosting. If your primary deployment reaches full capacity, and the overflow nodes have not completed initiating, any incoming calls during this period will be rejected with "capacity exceeded" messages. You have to balance the need for having standby capacity started up in time to meet the expected demand, against starting up nodes too early and incurring extra unnecessary costs.

Manually starting an overflow node

If you know that your system will need additional capacity at a specific time due to a predictable or scheduled spike in demand, but do not want to wait for the bursting threshold to be triggered before starting up the overflow nodes, you can manually start up any of your overflow nodes.

Do not manually start an overflow node too early. If you manually start up a node more than the Minimum lifetime minutes before the node is needed, it will most probably get automatically stopped again before it is used.

You can start overflow nodes via the management API or via the Administrator interface:

  • via the management API: the cloud_node status resource can be used to list all of the available overflow nodes, the cloud_monitored_location and cloud_overflow_location resources retrieve the current load on the primary locations and any currently active overflow locations respectively, and the start_cloudnode resource can be used to manually start up any overflow node. This means that a third-party scheduling system, for example, could be configured to start up the overflow nodes via the management API approximately 10 minutes before a large conference is due to start.

    For example, let's assume that you have:

    • a regular spike in conferencing capacity demand at 9:00am every morning
    • an even usage of about 20% of that spike level during the rest of the day
    • a 30:70 ratio between your "always on" capacity and your overflow cloud capacity

    we would recommend:

    • configuring a low bursting threshold, such as 10-20% of your "always on" capacity (i.e. if your "always on" capacity is 80 HD calls, then set the bursting threshold to 12)
    • getting your scheduling system to call the API to manually start up all of your overflow cloud nodes at 8:50am on weekdays.
  • via the Pexip Infinity Administrator interface: go to Status > Cloud bursting and select Start for the required nodes (the Start option is in the final column of the Cloud overflow nodes table).

Converting between overflow and "always on" GCP Conferencing Nodes

If you need to convert an existing "always on" GCP Conferencing Node into an overflow node:

  1. In GCP:

    1. Apply a label with a Key of pexip-cloud and an associated Value set to the Tag value that is shown in the Cloud bursting section of the Platform > Global settings page.
    2. Manually stop the node instance on GCP.
  2. In Pexip Infinity:

    1. Change the system location of the Conferencing Node to the overflow system location (e.g. "GCP burst").
    2. Disable the node's Enable distributed database setting.

      You should avoid frequent toggling of this setting. When changing this setting on multiple Conferencing Nodes, update one node at a time, waiting a few minutes before updating the next node.

If you need to convert an existing GCP overflow Conferencing Node into an "always on" node:

  1. In GCP:

    1. Remove the label with a Key of pexip-cloud from the GCP instance.
    2. Manually start the node instance on GCP.
  2. In Pexip Infinity:

    1. Change the system location of the Conferencing Node to a location other than the overflow system location.
    2. Enable the node's Enable distributed database setting.

      You should avoid frequent toggling of this setting. When changing this setting on multiple Conferencing Nodes, update one node at a time, waiting a few minutes before updating the next node.