Data replication in a cluster
Cluster members share data that is relevant to the ISAM configuration. We can update the configuration data on the primary master only. The other nodes in the cluster maintain local read-only replicas of the data from the primary master.
Any change to the cluster configuration or runtime parameters policy is automatically synchronized and applied to every node in the cluster. The Cluster Configuration management page in the LMI lists the nodes in the cluster. This list includes a Status column to indicate the status of the synchronization of system settings across the cluster.
If the changes to the system settings are not synchronized correctly on a particular node, the cluster administrator must investigate the problem. The administrator can examine the various log files on the node to determine why the change did not deploy successfully. When the problem is fixed, the administrator can either reboot the node, or rejoin the node to the cluster so that it applies the changes again. The Status column indicates whether the system settings on each node are up-to-date. This column does not indicate the status of any other synchronizations.
The data that is replicated across the cluster includes security settings, geolocation data, and system settings.
We can optionally configure the cluster to replicate the ISAM runtime settings and the certificate database settings. Replicating the runtime settings can provide high availability for the Policy Server. For more information, see High availability for the policy server.
Parent topic: Cluster support