Persistence Clusters Status Table

The persistence clusters status table presents the state of persistence clusters and services.

Clicking a cluster row expands a Servers List, detailing the persistence services in the cluster.

Columns

GUI Item Description
Cluster Status The health of the cluster based on the aggregated state values of its services.

For service state values, see Persistence Service States.

Name Name of the persistence cluster.
Services Status summary of the persistence services in the cluster.
Stores List of persistence stores that the cluster implements.
Note: The Attention tally in the GUI top bar does not include persistence services or eFTL services unless at least one service from the cluster is present. Nonetheless, even in a temporary situation where a cluster is configured but none of its services are present, the status table indicates that the cluster and its absent services are offline.

Commands

Icons at the right of each cluster row trigger commands:

  • Suspend all services in the cluster, in preparation for saving the contents of its persistence services. For background information, see Saving and Loading Persistence State, and its sub-topics. This command is used only when disk persistence is disabled.
  • Save the data state of all the persistence services in the cluster. This command is visible only when it is available. For background information, see Saving and Loading Persistence State, and its sub-topics. This command is used only when disk persistence is disabled.
  • Back up the disk(s). When disk persistence is enabled, this command backs up the files associated with disk persistence.
  • Force this cluster to form a quorum. This command icon is visible only when it is relevant. Before using this command, read Before Forcing a Quorum.

Restoring Backups

When restoring from backup files, use only the files created by a backup command. No live persistence files may be present.

The backup command creates a backup file for each persistence service. Rename the backup files and place them in the appropriate data directories before starting the servers.

Before performing a restoral, first identify the desired backup file for each persistence service. Then rename the backup file to <persistence_service_name>.persist and place it in the data directory for that persistence service.

Do not mix a backup file with the original live persistence files. All servers must be started from backup files (or empty), or all servers must be started from their original persistence files (or empty).

Note the following differences between backups and saving the state of the peristence cluster.

• You use backups only when disk persistence is enabled.
• Unlike saving the state of the persistence cluster (which involves suspending the cluster), backups do not prevent new clients from sending or receiving messages while the backup is in progress.