Manage a ClickHouse® cluster

Go to the Clusters page in the console.

Select the cluster you want to manage.

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

1. Under Resources:

   • Select a preset for CPU and RAM.

     A resource preset has the following structure:

     <cpu-platform>-c<number-of-cpu-cores>-m<gigabytes-of-ram>
     

     There are three available CPU platforms:

     • g: ARM Graviton

     • i: Intel (x86)

     • s: AMD (x86)

     For example, the i2-c2-m8 preset corresponds to an Intel-family machine with 2 virtual cores and 8 GB of RAM.

     Learn more about the availability of CPU platforms in areas and regions

   • Specify your SSD 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 6 hours to modify.

     Warning

     After you increase your SSD Storage capacity, 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.

Under Advanced:

• Under Maintenance settings, select between the arbitrary and scheduled maintenance:

  About maintenance settings

  If you select Arbitrary, DoubleCloud selects the maintenance window automatically. Usually, maintenance takes place at the earliest available time slot.

  Warning

  If your cluster has only one host, arbitrary maintenance can make it unavailable at a random time.

  To perform maintenance on a specific date and time, select By schedule and specify the day and time (UTC) when you want the cluster maintenance to be performed.

Under Cluster settings:

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

Click Submit.