system.histogram_metrics

Querying in ClickHouse CloudThe data in this system table is held locally on each node in ClickHouse Cloud. Obtaining a complete view of all data, therefore, requires the clusterAllReplicas function. See here for further details.

Description

This table contains histogram metrics that can be calculated instantly and exported in the Prometheus format. It is always up to date. Replaces the deprecated system.latency_log.

Columns

metric (String) — Metric name.
value (Float64) — Metric value.
description (String) — Metric description.
labels (Map(String, String)) — Metric labels.

Aliases:

name — Alias for metric.

Example

You can use a query like this to export all the histogram metrics in the Prometheus format.

SELECT
  metric AS name,
  toFloat64(value) AS value,
  description AS help,
  labels,
  'histogram' AS type
FROM system.histogram_metrics
FORMAT Prometheus

Metric descriptions

Metric	Description
`keeper_response_time_ms_bucket`	The response time of Keeper, in milliseconds.
`keeper_client_queue_duration_milliseconds_bucket`	Time requests spend waiting to be enqueued and waiting in the queue before being processed by the Keeper client, in milliseconds.
`keeper_receive_request_time_milliseconds_bucket`	Time to receive and parse a request from the client in the Keeper TCP handler, in milliseconds.
`keeper_dispatcher_requests_queue_time_milliseconds_bucket`	Time a request spends in the Keeper dispatcher requests queue, in milliseconds.
`keeper_write_pre_commit_time_milliseconds_bucket`	Time to preprocess a write request before Raft commit, in milliseconds.
`keeper_write_commit_time_milliseconds_bucket`	Time to process a write request after Raft commit, in milliseconds.
`keeper_dispatcher_responses_queue_time_milliseconds_bucket`	Time a response spends in the Keeper dispatcher responses queue, in milliseconds.
`keeper_send_response_time_milliseconds_bucket`	Time to send a response to the client in the Keeper TCP handler (includes queueing and writing to socket), in milliseconds.
`keeper_read_wait_for_write_time_milliseconds_bucket`	Time a read request waits for the write request it depends on to complete, in milliseconds.
`keeper_read_process_time_milliseconds_bucket`	Time to process a read request in Keeper, in milliseconds.
`keeper_batch_size_elements_bucket`	Batch size sent to Raft, in elements.
`keeper_batch_size_bytes_bucket`	Batch size sent to Raft, in bytes.
`filesystem_cache_evicted_segment_hits_bucket`	Distribution of cache-hit counts on file segments at the moment of their eviction, labelled by cache name.
`filesystem_cache_evicted_segment_size_bytes_bucket`	Distribution of byte sizes of evicted file segments, labelled by cache name.
`filesystem_cache_evicted_segment_hits_by_user_bucket`	Distribution of cache-hit counts on evicted file segments, labelled by cache name and user id.
`filesystem_cache_evicted_segment_size_bytes_by_user_bucket`	Distribution of byte sizes of evicted file segments, labelled by cache name and user id.

SQL Reference

Description

Columns

Example

Metric descriptions

See Also

​Description

​Columns

​Example

​Metric descriptions

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Description

Columns

Example

Metric descriptions

See Also