Adding a New Compute Node to Existing Contrail Cluster

Note:

We recommend using Contrail Command to add compute nodes to existing Contrail clusters in most Contrail Networking deployments. See Adding a New Compute Node to Existing Contrail Cluster Using Contrail Command.

The procedure in this document should only be performed by network administrators with significant YAML file expertise in environments not using the Contrail Command GUI.

This is initial process for adding a new compute node to existing Contrail OpenStack cluster.

Assume Contrail cluster is successfully provisioned by the following instances.yaml file.

Note:

The password values in this output are included for illustrative purposes only. We strongly recommend creating a unique username and password combination whenever possible.

Run the following commands to add a new compute node to an existing Contrail OpenStack cluster.

Edit the instances.yaml file to add a compute node, srvr5.

Note:

The password values in this output are included for illustrative purposes only. We strongly recommend creating a unique username and password combination whenever possible.

Run the configure_instances.yml playbook with the new instances.yaml file.
It will install the required software and also, prepare the new node for running the relevant containers.
Run playbooks.
Note:
The --tags nova option runs only the nova role so that the other containers are not affected.

It is not recommended to omit the above option. If the option is omitted, especially when multiple OpenStack nodes are running with HA, the MariaDB Galera cluster will go out of sync and will not converge. In such situation, the only solution is to re-provision the entire OpenStack cluster.

You can also add or remove a compute node to existing Contrail cluster using Contrail Command UI. For details, refer to Adding a New Compute Node to Existing Contrail Cluster Using Contrail Command.