ClickHouse/docs/en/operations/system-tables/metric_log.md
Anna a6fb067a75
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Co-authored-by: Anna Devyatova <annadevyatova@yandex-team.ru>
Co-authored-by: Sergei Shtykov <bayonet@yandex-team.ru>
Co-authored-by: alexey-milovidov <milovidov@yandex-team.ru>
2020-08-06 11:50:29 +03:00

2.5 KiB

system.metric_log

Contains history of metrics values from tables system.metrics and system.events, periodically flushed to disk. To turn on metrics history collection on system.metric_log, create /etc/clickhouse-server/config.d/metric_log.xml with following content:

<yandex>
    <metric_log>
        <database>system</database>
        <table>metric_log</table>
        <flush_interval_milliseconds>7500</flush_interval_milliseconds>
        <collect_interval_milliseconds>1000</collect_interval_milliseconds>
    </metric_log>
</yandex>

Example

SELECT * FROM system.metric_log LIMIT 1 FORMAT Vertical;
Row 1:
──────
event_date:                                                 2020-02-18
event_time:                                                 2020-02-18 07:15:33
milliseconds:                                               554
ProfileEvent_Query:                                         0
ProfileEvent_SelectQuery:                                   0
ProfileEvent_InsertQuery:                                   0
ProfileEvent_FileOpen:                                      0
ProfileEvent_Seek:                                          0
ProfileEvent_ReadBufferFromFileDescriptorRead:              1
ProfileEvent_ReadBufferFromFileDescriptorReadFailed:        0
ProfileEvent_ReadBufferFromFileDescriptorReadBytes:         0
ProfileEvent_WriteBufferFromFileDescriptorWrite:            1
ProfileEvent_WriteBufferFromFileDescriptorWriteFailed:      0
ProfileEvent_WriteBufferFromFileDescriptorWriteBytes:       56
...
CurrentMetric_Query:                                        0
CurrentMetric_Merge:                                        0
CurrentMetric_PartMutation:                                 0
CurrentMetric_ReplicatedFetch:                              0
CurrentMetric_ReplicatedSend:                               0
CurrentMetric_ReplicatedChecks:                             0
...

See also

Original article