Updating a ClickHouse® cluster
How do I add a host to a cluster?
To add a host, follow this guide. You can also add new hosts to a cluster when creating a shard.
Can I set join_use_nulls to 1 using the CLI?
Yes. To do this, when creating a user or updating user settings, pass the desired join_use_nulls setting value in the --settings parameter. For example:
yc managed-clickhouse user update <username> \
--cluster-name=<cluster_name> \
--settings="join_use_nulls=1"
For more information, see the documentation.
Is a cluster available when being updated?
If it is a multi-host cluster, there is no downtime while updating it, since the hosts are updated one by one. Only individual hosts are unavailable when the cluster is being restarted.
How do I change the time zone?
Change the timezone or session_timezone setting for ClickHouse® by following this guide.
Is a cluster unavailable when adding replicas?
Yes, there is a short downtime when restarting a cluster.
How do I grant a user read-only permissions?
To do this, when creating or editing a user via the CLI, pass readonly=1 in the --settings parameter. For example:
yc managed-clickhouse user update <username> \
--cluster-name=<cluster_name> \
--settings="readonly=1"
For more information, see the documentation.
How do I increase the memory limit?
Update the user settings and set the desired Max memory usage parameter value.
Can I change the disk type?
No, you can only select the disk type when creating a cluster or restoring it from a backup.
Can I change a network and subnets?
No, you can only select a network and subnets for hosts when creating a cluster or restoring it from a backup.
How to change the distribution of data across shards in a cluster?
In an existing cluster, you cannot change the location of data in shards. To make the change, transfer data to a new cluster with shard redistribution using Yandex Data Transfer.
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