Switching the master
In a failover Managed Service for Redis cluster with multiple hosts, you can switch the master role from the current master host to the replica host. After this operation, the current master host becomes the replica host of the new master.
It takes several minutes on average to switch, and the cluster is available during that time.
A sharded cluster contains one or more master hosts: one per shard. Switching the master for a sharded cluster is done for each shard one by one.
To switch the master in a non-sharded cluster:
- In the management console, go to the folder containing a non-sharded cluster.
- Select Managed Service for Redis.
- Click the cluster name and select the Hosts tab.
- In the line of the host with the
MASTERrole, click and select Switch master host. - In the window that opens, select the I want to switch the master option and click Switch.
To switch the master in a sharded cluster:
- In the management console, go to the folder containing a sharded cluster.
- Select Managed Service for Redis.
- Click the cluster name and select the Hosts tab.
- In the line of the host with the
MASTERrole, click and select Switch master host. - In the window that opens, click Switch.
If you do not have the Yandex Cloud command line interface yet, install and initialize it.
The folder specified in the CLI profile is used by default. You can specify a different folder using the --folder-name or --folder-id parameter.
To switch the master in a non-sharded cluster, run the command:
yc managed-redis cluster start-failover \
--name <cluster_name>
To switch the master in a sharded cluster, run the command:
yc managed-redis cluster start-failover \
--name <cluster_name> \
--hostnames <name_of_current_master_host>
You can request the cluster name with a list of clusters in the folder and the name of the master host for the desired shard with a list of hosts in the cluster.
To switch the master, use the startFailover REST API method for the Cluster resource or the ClusterService/StartFailover gRPC API call and provide the following in the request:
- ID of the cluster where you want to switch the master, in the
clusterIdparameter. To find out the cluster ID, get a list of clusters in the folder. - For a sharded cluster only: the name of the current master host of the desired shard in the
hostNamesparameter. To find out the name, get a list of hosts in the cluster.