Summary

This PR adds support for configuring Zookeeper compression through the ClickHouseInstallation CRD by introducing the use_compression field in the zookeeper configuration section as defined in the ClickHouse server config settings

Changes

• Added use_compression boolean field to the Zookeeper configuration spec in the CRD
• Updated the operator to properly generate <use_compression> XML configuration when specified
• Field is optional and defaults to false to maintain backward compatibility

Configuration Example

  apiVersion: "clickhouse.altinity.com/v1"
  kind: ClickHouseInstallation
  metadata:
    name: example
  spec:
    configuration:
      zookeeper:
        nodes:
          - host: keeper.example.com
            port: 2181
        session_timeout_ms: 30000
        operation_timeout_ms: 10000
        root: /clickhouse
        identity: user:password
        use_compression: "true"  # <-- New field

Testing

In a local KinD environment, confirmed the operator correctly generates the Zookeeper configuration:

<yandex>
    <zookeeper>
        <node>
            <host>keeper-local.clickhouse-kind.svc.cluster.local</host>
            <port>2181</port>
        </node>
        <session_timeout_ms>30000</session_timeout_ms>
        <operation_timeout_ms>10000</operation_timeout_ms>
        <root>/local</root>
        <identity>user:password</identity>
        <use_compression>true</use_compression>
    </zookeeper>
</yandex>

Network Traffic Comparison

Measured network traffic for identical operations (creating ReplicatedMergeTree table + inserting 10,000 rows):

Backward Compatibility

• The field is optional and omitting it maintains current behavior (no compression)
• Existing ClickHouseInstallation resources will continue to work without modification
• No changes required for users who don't need compression

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