ClickHouse/docs/en/operations/system-tables/asynchronous_metric_log.md

system.asynchronous_metric_log

Contains the historical values for system.asynchronous_metrics, which are saved once per minute. This feature is enabled by default.

Columns:

• event_date (Date) — Event date.
• event_time (DateTime) — Event time.
• name (String) — Metric name.
• value (Float64) — Metric value.

Example

SELECT * FROM system.asynchronous_metric_log LIMIT 10

┌─event_date─┬──────────event_time─┬─name─────────────────────────────────────┬────value─┐
│ 2020-06-22 │ 2020-06-22 06:57:30 │ jemalloc.arenas.all.pmuzzy               │        0 │
│ 2020-06-22 │ 2020-06-22 06:57:30 │ jemalloc.arenas.all.pdirty               │     4214 │
│ 2020-06-22 │ 2020-06-22 06:57:30 │ jemalloc.background_thread.run_intervals │        0 │
│ 2020-06-22 │ 2020-06-22 06:57:30 │ jemalloc.background_thread.num_runs      │        0 │
│ 2020-06-22 │ 2020-06-22 06:57:30 │ jemalloc.retained                        │ 17657856 │
│ 2020-06-22 │ 2020-06-22 06:57:30 │ jemalloc.mapped                          │ 71471104 │
│ 2020-06-22 │ 2020-06-22 06:57:30 │ jemalloc.resident                        │ 61538304 │
│ 2020-06-22 │ 2020-06-22 06:57:30 │ jemalloc.metadata                        │  6199264 │
│ 2020-06-22 │ 2020-06-22 06:57:30 │ jemalloc.allocated                       │ 38074336 │
│ 2020-06-22 │ 2020-06-22 06:57:30 │ jemalloc.epoch                           │        2 │
└────────────┴─────────────────────┴──────────────────────────────────────────┴──────────┘

See Also

• system.asynchronous_metrics — Contains metrics that are calculated periodically in the background.
• system.metric_log — Contains history of metrics values from tables system.metrics and system.events, periodically flushed to disk.