Creating a cluster

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You can configure multiple appliances into a cluster that shares configuration information and runtime information. Use the Cluster Configuration management page to administer cluster support for the appliance.

About this task

The Cluster Configuration page is not available in the LMI when the appliance runs in a container environment.

In a cluster, you must designate one of the appliances as the primary master. You can designate up to three subordinate masters, which are called the secondary, tertiary, and quaternary masters. The cluster services can fail over between these masters. The remaining appliances serve as nodes.

You must activate the primary and secondary masters of the cluster at the highest level of all the nodes in the cluster. For example, if any of the nodes have been activated with the Advanced Access Control module, the primary and secondary masters must also be activated for Advanced Access Control. Activation levels are validated when:

  • A node joins the cluster. Validation ensures that the primary and secondary masters are activated to at least the same level.
  • A new primary or secondary master is set to ensure that the activation level of the new master is at least at the same level of the current primary master.

By default, every appliance operates as a stand-alone cluster with only a single node. You can optionally configure a group of appliances into a cluster with multiple nodes.

For detailed information about clusters, see Cluster support.

Procedure

  1. Select an appliance to be the primary master. You can choose any appliance as the primary master if it is not a member of another cluster. If the selected appliance is in another cluster, you must unregister it before you can appoint it as the primary master of a new cluster.
  2. On the General tab of the Cluster Configuration page:
    1. Select the Multinode option.
    2. Click Create Cluster.
    3. In the Create Cluster window, configure the Cluster Identifier, and then click Create Cluster.
    Note: For more information about the Cluster Identifier, see Cluster general configuration reference.
  3. Save and deploy this update. The chosen appliance is configured as the primary master of a cluster that can contain multiple nodes.
  4. Export the cluster signature file on the primary master. The cluster signature file contains configuration information so that cluster members can identify and communicate with the primary master.
  5. Join appliances to the cluster by importing the cluster signature file on each appliance that you want to become a cluster member. The process of joining an appliance to the cluster is a registration.
  6. Update the cluster configuration on the primary master. As part of the cluster configuration, you can define more masters from the pool of registered nodes. For more information, see Failover in a cluster.
  7. Save and deploy the configuration changes.
    Note: As a rule, try to limit the number of changes that are made to the cluster configuration in a single policy update.