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. Enabled by default.

Columns:

• event_date (Date) — Event date.
• event_time (DateTime) — Event time.
• event_time_microseconds (DateTime64) — Event time with microseconds resolution.
• name (String) — Metric name.
• value (Float64) — Metric value.

Example

SELECT * FROM system.asynchronous_metric_log LIMIT 10

┌─event_date─┬──────────event_time─┬────event_time_microseconds─┬─name─────────────────────────────────────┬─────value─┐
│ 2020-09-05 │ 2020-09-05 15:56:30 │ 2020-09-05 15:56:30.025227 │ CPUFrequencyMHz_0                        │    2120.9 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ 2020-09-05 15:56:30.025227 │ jemalloc.arenas.all.pmuzzy               │       743 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ 2020-09-05 15:56:30.025227 │ jemalloc.arenas.all.pdirty               │     26288 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ 2020-09-05 15:56:30.025227 │ jemalloc.background_thread.run_intervals │         0 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ 2020-09-05 15:56:30.025227 │ jemalloc.background_thread.num_runs      │         0 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ 2020-09-05 15:56:30.025227 │ jemalloc.retained                        │  60694528 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ 2020-09-05 15:56:30.025227 │ jemalloc.mapped                          │ 303161344 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ 2020-09-05 15:56:30.025227 │ jemalloc.resident                        │ 260931584 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ 2020-09-05 15:56:30.025227 │ jemalloc.metadata                        │  12079488 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ 2020-09-05 15:56:30.025227 │ jemalloc.allocated                       │ 133756128 │
└────────────┴─────────────────────┴────────────────────────────┴──────────────────────────────────────────┴───────────┘

See Also

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

Original article