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Scale MySQL sync cluster
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Scale MySQL sync cluster

Cloud database cluster MySQL sync can scale. For example:

  • increase vCPU and RAM to improve cluster performance;
  • change the configuration line with local disk to another line with local disk — disk size must be larger than in the previous configuration, the number of vCPUs and RAM can be reduced or increased. It is possible to change a local disk lineup to a network disk lineup and vice versa only when cluster recovery.

Check out the list node configurations.

Configuration change process depends on the availability of replicas.

Principle of operation⁠

The process of changing the configuration depends on the availability of replicas:

  • if there are no replicas in the cluster — the master node will be stopped while the changes are applied and the cluster will be temporarily unavailable for reading and writing;
  • if there are replicas in the cluster — the cluster will be read and write accessible while the changes are being applied. The replicas will be stopped one by one and the configuration of each replica will be changed. The master node will then switch to one of the replicas and the configuration of the past master node will be changed.

The configuration change time depends on the amount of data in the cluster.

Scale the cluster⁠

carefully

If you have previously changed DBMS settings, they may be reset after scaling. Read more about settings MySQL sync when scaling the cluster.

Scale the cluster when users are least active.

  1. To avoid stopping the master node in a cluster without replicas, add a line. When scaling is complete, the replica can be deleted.

  2. in control panels from the top menu, press Products and select Managed databases.

  3. Open the tab Active.

  4. Open the cluster page → tab Settings.

  5. Click Scale the cluster.

  6. Pick another configuration. You can:

    • Select the configuration with the larger disk space only;
    • reduce or increase the number of vCPUs and RAM;
    • change a configuration line with a local disk to another line with a local disk. You can change a local disk ruler to a network disk ruler and vice versa only by cluster recovery.

  7. Optional: increase the number of lines in the cluster.

  8. Click Save.

  9. After scaling clear the DNS cache.

  10. Verify that the cluster has scaled correctly.

Clear DNS cache⁠

  1. Open the CLI.

  2. Clear the DNS cache:

    sudo systemctl restart systemd-resolved