Maintenance in Managed Service for Redis
Maintenance means:
- Automatic installation of Redis updates and revisions for hosts (including disabled clusters).
- Changes to the host class and storage size.
- Other maintenance activities.
Major DBMS version is not changed during maintenance.
Maintenance window
You can set the preferred maintenance time when creating a cluster or updating its settings:
- arbitrary (default): Maintenance is possible at any time.
- by schedule: Set the preferred maintenance start time, i.e., the day and time (UTC) you want to perform maintenance at. For example, you can choose a time when the cluster is least loaded.
Maintenance procedure
The way of running the Managed Service for Redis cluster maintenance depends on the number of hosts.
Maintenance is performed as follows:
- Replica hosts undergo maintenance one by one. The hosts are queued randomly. A replica becomes unavailable while it is being restarted during maintenance.
- Maintenance is performed on a master host. If it is restarted and becomes unavailable, one of the replicas takes its role. A single-host cluster will be unavailable during its maintenance.