Configure an Automation Orchestrator cluster

You can configure your new Automation Orchestrator deployment to run in high availability by deploying three nodes and connecting them as a cluster.

An Automation Orchestrator cluster consists of three Automation Orchestrator instances that share a common PostgreSQL database. The database of the configured Automation Orchestrator cluster can only run in asynchronous mode.

To create an Automation Orchestrator cluster, you must select one Automation Orchestrator instance to be the primary node of the cluster. After configuring the primary node, you join the secondary nodes to it.

The Automation Orchestrator cluster you created is pre-configured with automatic failover.

Note: Failure of the automatic failover can lead to loss of database data.

Prerequisites

• Download and deploy three standalone Automation Orchestrator instances. Go to Download and Deploy the Automation Orchestrator Appliance.
  Note: A clustered Automation Orchestrator environment can consist of three nodes.
• Verify that SSH access is enabled for all Automation Orchestrator nodes. Go to Activate or Deactivate SSH Access to the Automation Orchestrator Appliance.
• Configure a load balancer server. Go to Load Balancing Guide.

Procedure

1. Configure the primary node.
   1. Log in to the Automation Orchestrator Appliance command line of the primary node over SSH as root.
   2. To configure the cluster load balancer server, run the vracli load-balancer set load_balancer_FQDN command.
   3. Log in to the Control Center of the primary node and select Host Settings.
   4. Click Change and set the host address of the connected load balancer server.
   5. Configure the authentication provider. Go to Configuring a Standalone Automation Orchestrator Server.
2. Join secondary nodes to primary node.
   1. Log in to the Automation Orchestrator Appliance command line of the secondary node over SSH as root.
   2. To join the secondary node to the primary node, run the vracli cluster join primary_node_hostname_or_IP command.
   3. Enter the root password of the primary node.
   4. Repeat the procedure for other secondary node.
3. (Optional) If your primary node uses a custom certificate, you must either set the certificate in the appliance or generate a new certificate. Go to Generate a custom TLS certificate for Automation Orchestrator.
   Note: The file containing the certificate chain must be PEM-encoded.
4. Finish the cluster deployment.
   1. Log in to the Automation Orchestrator Appliance command line of the primary node over SSH as root.
   2. To confirm that all nodes are in a ready state, run the kubectl -n prelude get nodes command.
   3. Run the /opt/scripts/deploy.sh script and wait for the deployment to finish.

Results

You have created an Automation Orchestrator cluster. After creating the cluster, you can access your Automation Orchestrator environment only from the FQDN address of your load balancer server.

Note: Because you can only access the Control Center of the cluster with the root password of the load balancer, you cannot edit the configuration of a cluster node if it has a different root password. To edit the configuration of this node, remove it from the load balancer, edit the configuration in the Control Center, and add the node back to the load balancer.

What to do next

To monitor the state of the Automation Orchestrator cluster, log in to the Automation Orchestrator Client and navigate to the System tab of the dashboard. Go to Monitoring an Automation Orchestrator cluster.