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

slug
/en/operations/system-tables/metric_log

metric_log

Contains history of metrics values from tables system.metrics and system.events, periodically flushed to disk.

Columns:

• hostname (LowCardinality(String)) — Hostname of the server executing the query.
• event_date (Date) — Event date.
• event_time (DateTime) — Event time.
• event_time_microseconds (DateTime64) — Event time with microseconds resolution.

Example

SELECT * FROM system.metric_log LIMIT 1 FORMAT Vertical;

Row 1:
──────
hostname:                                                        clickhouse.eu-central1.internal
event_date:                                                      2020-09-05
event_time:                                                      2020-09-05 16:22:33
event_time_microseconds:                                         2020-09-05 16:22:33.196807
milliseconds:                                                    196
ProfileEvent_Query:                                              0
ProfileEvent_SelectQuery:                                        0
ProfileEvent_InsertQuery:                                        0
ProfileEvent_FailedQuery:                                        0
ProfileEvent_FailedSelectQuery:                                  0
...
...
CurrentMetric_Revision:                                          54439
CurrentMetric_VersionInteger:                                    20009001
CurrentMetric_RWLockWaitingReaders:                              0
CurrentMetric_RWLockWaitingWriters:                              0
CurrentMetric_RWLockActiveReaders:                               0
CurrentMetric_RWLockActiveWriters:                               0
CurrentMetric_GlobalThread:                                      74
CurrentMetric_GlobalThreadActive:                                26
CurrentMetric_LocalThread:                                       0
CurrentMetric_LocalThreadActive:                                 0
CurrentMetric_DistributedFilesToInsert:                          0

See also

• metric_log setting — Enabling and disabling the setting.
• system.asynchronous_metrics — Contains periodically calculated metrics.
• system.events — Contains a number of events that occurred.
• system.metrics — Contains instantly calculated metrics.
• Monitoring — Base concepts of ClickHouse monitoring.