ClickHouse¶

The clickhouse probe monitors a ClickHouse server by scraping the standard Prometheus /metrics endpoint (available since ClickHouse 20.1), mapping the key instantaneous gauges, async metrics, and cumulative profile-event counters.

Quick start¶

probes:
  - name: clickhouse
    type: clickhouse
    params:
      endpoint: http://localhost:8123

Parameters¶

Parameter	Default	Description
`endpoint`	`http://localhost:8123`	ClickHouse HTTP interface base URL
`username`	`default`	ClickHouse user (must have SELECT access to system tables)
`password`	—	User password

Metrics¶

Metric	Unit	Description
`senhub.clickhouse.up`	1	1 when the `/metrics` endpoint answered successfully
`clickhouse.queries.active`	{query}	Queries currently executing (`ClickHouseMetrics_Query`)
`clickhouse.connections.tcp`	{connection}	Open TCP connections from clients
`clickhouse.connections.http`	{connection}	Open HTTP connections from clients
`clickhouse.merges.active`	{merge}	Background merge operations currently running
`clickhouse.parts.total`	{part}	Total data parts across all tables
`clickhouse.memory.used`	By	Process memory allocated by the ClickHouse server
`clickhouse.queries.inserted_rows`	{row}	Rows inserted since server start (profile counter)
`clickhouse.queries.select_count`	{query}	SELECT queries since server start
`clickhouse.queries.insert_count`	{query}	INSERT queries since server start

Operational notes¶

The probe uses the Prometheus text format at /metrics, not the SQL interface. No extra user grant is required unless metrics access is restricted.
ClickHouse 20.1+ exposes the Prometheus endpoint by default on the HTTP port (8123). Older installations require prometheus.port in the server config.