Updating a MySQL® cluster
Can I manage a cluster using SQL commands?
There are some restrictions on cluster management using SQL commands. For more information, see SQL command limits.
How do I reduce the size of a disk?
You cannot reduce the size of a cluster storage.
You can create a new cluster with smaller storage and migrate your data to it.
How do I increase the size of a disk?
You cannot directly increase the size of non-replicated SSD storage: follow the steps outlined in this guide.
If you need it increased, restore the cluster from a backup and set the appropriate size.
You can check the disk type in the management console. To do this, find the Storage setting under Resources on the cluster page.
How do I change the disk type?
To change the disk type, restore your cluster from a backup.
Why cannot I add or delete a host?
The number of hosts in clusters is limited by quotas. Before adding a host, check the resources currently in use: open the Quotas page and find the Managed Databases section.
You can delete a host as long as it is not the only host in the cluster. To replace the only host, first create a new host and then delete the old one.
Clusters with local disks have a fault-tolerant three-host configuration. Using fewer hosts is not allowed.
How do I perform a manual failover?
In a fault-tolerant multi-host cluster, you can switch the master role from the current master host to a replica host. After the failover, the current master host becomes a replica for the new master.
- Go to the cluster page and select the Hosts tab.
- Click Switch master.
If you do not have the Yandex Cloud CLI installed yet, install and initialize it.
By default, the CLI uses the folder specified when creating the profile. To change the default folder, use the yc config set folder-id <folder_ID> command. You can also set a different folder for any specific command using the --folder-name or --folder-id parameter.
To switch the master:
-
See the description of the CLI command for initiating a failover:
yc managed-mysql cluster start-failover --help -
Run the
yc managed-mysql cluster start-failovercommand.
How do I restart a host?
You cannot restart a separate cluster host. To restart hosts, stop and restart the cluster.