Maintenance in Yandex Managed Service for Valkey™

Maintenance includes:

• Automatic installation of DBMS updates and patches for hosts (including for stopped clusters).
• Scheduled automatic storage expansion.
• Other maintenance activities.

A major DBMS version update is not part of maintenance. For more information about major version changes, see Valkey™ version upgrade.

Maintenance windowMaintenance window

You can set the maintenance window 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 workflowMaintenance workflow

The Yandex Managed Service for Valkey™ cluster maintenance workflow depends on the number of hosts and sharding.

Non-sharded clusterNon-sharded cluster

The maintenance procedure is as follows:

1. Replica hosts undergo maintenance one by one. Such hosts are queued randomly. If a replica needs to be restarted during maintenance, it will become unavailable.
2. Maintenance is performed on a master host. If the master host needs restarting and becomes unavailable, one of the replicas will assume its role. A single-host cluster will be unavailable during its maintenance.

Sharded clusterSharded cluster

In sharded clusters, maintenance is performed shard by shard in ascending order by shard number. Host maintenance in each shard is the same as in non-sharded clusters:

1. Replica hosts undergo maintenance one by one. Such hosts are queued randomly. If a replica needs to be restarted during maintenance, it will become unavailable.
2. Maintenance is performed on a master host. If the master host needs to restart and becomes unavailable, one of the replicas will assume its role. A single-host shard will be unavailable during its maintenance.