Frequently asked questions about DoubleCloud Managed ClickHouse®

Questions:

Can I connect to a ClickHouse® cluster without SSL?

You can connect to DoubleCloud ClickHouse® clusters only via an SSL connection.

Will there be downtime during cluster update?

The ClickHouse® cluster update process depends on a number of its shards and hosts:

  • If your cluster has a single host, it will need to restart, and you'll have downtime during the restart process.

  • If your cluster has more than three hosts, they'll update and restart sequentially, so you'll experience no downtime.

Can I create a read-only user for my ClickHouse® cluster?

To create a read-only user for your ClickHouse® cluster, see {#T}.

I've run out of space on my cluster, and I'm already at the maximum storage capacity

If your cluster's at the maximum storage capacity, consider these options:

  • Select a higher resource preset.

    For example, the s1-c8-m32 preset has the maximum storage quota of 2 TB, while the s1-c32-m128 has the maximum quota of 8 TB.

  • If your cluster already has the maximum storage size of 8 TB, contact our technical support to request a storage quota increase.

What's the retention period for backups? Is there a limit to the number of backups?

DoubleCloud Managed ClickHouse® service stores the last 7 backups. These backups are created automatically every 24 hours, and the Managed ClickHouse® service retains each of them for 7 days.

When you create a manual backup by clicking the Create backup, it adds another item on the list. The service will store this backup also for 7 days.

How can I estimate the time needed to restore a cluster from a backup?

To estimate the time it takes to recover your cluster from a backup, use the average speed value of 100 megabits per second.

How can I see the disk space used by the tables?

To see the size of a table on your cluster, send the following query via the clickhouse-client:

SELECT database, name, formatReadableSize(total_bytes)
FROM system.tables
ORDER BY total_bytes DESC

Where can I see the prices for available ClickHouse® cluster configurations?

You can see the available configurations with estimated payment sizes at the Pricing page of our website.