Maintenance in Managed Service for OpenSearch
Maintenance means:
- Automatic installation of OpenSearch updates and revisions for host groups (including disabled clusters).
- Scheduled automatic increase of storage size.
- Other maintenance activities.
Changing a major DBMS version is not part of maintenance. For more information about migrating between major versions, see Upgrading the OpenSearch version.
Maintenance window
You can set the preferred maintenance time when creating a cluster or updating its settings:
- The arbitrary option (default) allows performing maintenance at any time.
- The by schedule option allows setting the preferred maintenance start day and time (UTC). For example, you can choose a time when the cluster is least loaded.
Maintenance procedure
In Managed Service for OpenSearch single-host clusters, a single host undergoes maintenance. This means, if a cluster needs to be restarted during maintenance, it will become unavailable.
In multi-host clusters, hosts undergo maintenance one by one. The hosts are queued randomly. If a host needs to be restarted during maintenance, it becomes unavailable while being restarted. If you access a cluster using the FQDN of the OpenSearch host, the cluster may become unavailable. To make your application continuously available, access the cluster using a special FQDN always pointing to the available host.