Manage a ClickHouse® cluster

    1. Go to the Clusters overview page.

    2. Select the name of the cluster you want to manage.

    3. Click Edit in the upper-right corner of the page and configure resources:

      1. Under Resources:

        • Select a preset for CPU and RAM.

        • Specify your Storage capacity.

          Note

          After you have created a cluster, you can only increase the storage capacity. You can't decrease the storage capacity.

          When you increase your storage capacity, it's available for use immediately after you submit the new configuration. However, the whole process of modifying your storage volume may take from minutes to hours, depending on the volume increase applied. For example, a volume of 1 TB in size typically takes up to six hours to modify.

          Warning

          After you increase your Storage capacity, please wait at least six hours per 1 TB to modify it again.

        • Choose a number of Replicas. Selecting two or three replicas will double or triple the number of hosts per shard, respectively.

        • Select a number of Shards.

          Have at least two shards on your cluster to use all the benefits of sharding.

          Using a distributed table and a single shard is equivalent to using replication with no sharding. It protects against data loss when one or more replica hosts fail but provides no distributed data storage and doesn't improve query performance.

      Warning

      Be aware when you lower the number of existing replicas - under certain conditions, this may lead to data loss.

    4. Specify or adjust your cluster's DBMS settings. For more information, see the Settings reference.

    5. Click Submit.

    See also: