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 yet, install and initialize it.
The folder used by default is the one specified when creating the CLI profile. To change the default folder, use the yc config set folder-id <folder_ID> command. You can also specify a different folder for any command using --folder-name or --folder-id. If you access a resource by its name, the search will be limited to the default folder. If you access a resource by its ID, the search will be global, i.e., through all folders based on access permissions.
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.
Why do I get an error when stopping the cluster?
Error message:
cluster has no backups. If you want to stop the cluster, make a backup
The error occurs because you can stop an Managed Service for MySQL® cluster only if there is at least one backup of the cluster.
Solution: Wait until an automatic backup is created or create a backup manually.