metrics
Contains metrics which can be calculated instantly, or have a current value. For example, the number of simultaneously processed queries or the current replica delay. This table is always up to date.
Columns:
metric
(String) β Metric name.value
(Int64) β Metric value.description
(String) β Metric description.
The list of supported metrics you can find in the src/Common/CurrentMetrics.cpp source file of ClickHouse.
Example
SELECT * FROM system.metrics LIMIT 10
ββmetricββββββββββββββββββββββββββββββββ¬βvalueββ¬βdescriptionβββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ
β Query β 1 β Number of executing queries β
β Merge β 0 β Number of executing background merges β
β PartMutation β 0 β Number of mutations (ALTER DELETE/UPDATE) β
β ReplicatedFetch β 0 β Number of data parts being fetched from replicas β
β ReplicatedSend β 0 β Number of data parts being sent to replicas β
β ReplicatedChecks β 0 β Number of data parts checking for consistency β
β BackgroundMergesAndMutationsPoolTask β 0 β Number of active merges and mutations in an associated background pool β
β BackgroundFetchesPoolTask β 0 β Number of active fetches in an associated background pool β
β BackgroundCommonPoolTask β 0 β Number of active tasks in an associated background pool β
β BackgroundMovePoolTask β 0 β Number of active tasks in BackgroundProcessingPool for moves β
ββββββββββββββββββββββββββββββββββββββββ΄ββββββββ΄βββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ
See Also
- system.asynchronous_metrics β Contains periodically calculated metrics.
- system.events β Contains a number of events that occurred.
- system.metric_log β Contains a history of metrics values from tables
system.metrics
andsystem.events
. - Monitoring β Base concepts of ClickHouse monitoring.