Host classes in Managed Service for ClickHouse®

The host class determines the computing power allocated for each host in a cluster. When you change the host class for a cluster, all existing hosts change accordingly.

The host class also determines which disk types are available:

• s1, s2, s3, m2, m3, c3: network-ssd, network-hdd, local-ssd, network-ssd-nonreplicated, network-ssd-io-m3.
• b1, b2, b3: network-ssd, network-hdd.

For storage size limitations, see Quotas and limits.

The host class affects the Max server memory usage DBMS setting that limits the amount of RAM available for ClickHouse® to run. For more information, see Memory management.

Available host classesAvailable host classes

Hosts in Managed Service for ClickHouse® clusters are deployed on Yandex Compute Cloud VMs. You can create these VMs on any platforms Compute Cloud supports. To learn more about the platforms, see Platforms.

The full list of possible host configurations on each platform is provided below.

Configuration types:

• s1, s2, s3: Standard configurations with 4:1 RAM GB to vCPU ratio.

• m2, m3: Configurations with an increased RAM GB to vCPU ratio (8:1). These configurations may be useful for clusters with higher cache requirements.

• c3: Configurations with a reduced RAM GB to vCPU ratio (2:1). These configurations may be useful for clusters with higher processor performance requirements.

• b1, b2, b3: Configurations with a guaranteed vCPU share under 100%. This host class is intended for test load, while the minimum recommended host configuration for production solutions is two vCPUs with a guaranteed share of 50%.

  Note

  Hosts with a guaranteed vCPU share under 50% cannot be used in multi-host clusters.

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