MySQL Server Query Cache Prunes Percent Monitor Monitor

  • ID:  Microsoft.MySQLServer.ManagedServer.Unix.QueryCachePrunesPct.Monitor
  • Description:  MySQL Server Query Cache Prunes Percent Monitor
  • Target:  Monitored MySQL Server (Linux)
  • Enabled:  On Standard Monitoring

Operational States

Name State Description
Under Threshold Success Under Threshold
Over Warning Threshold Warning Over Warning Threshold
Over Error Threshold Error Over Error Threshold

Overridable Parameters

Parameter Name Default Value Description Override
Interval 300 Interval in seconds
Number of Samples 3 Number of Samples
Warning Threshold 70 Warning Threshold
Error Threshold 80 Error Threshold

Alert Details

Monitor State Message Priority Severity Auto Resolution
Over Warning Threshold (Warning) MySQL Server Query Cache Prunes Percent Medium Match Monitor Health Yes

Run As Profiles

Name
Default

Monitor Knowledgebase

Summary

The percent of prunes from the query cache. Query cache pruning occurs when the query cache is full and the least recently used query is pruned. The query cache size is controlled using the global variable “query_cache_size”. The monitor threshold is analyzed against an average of values returned in polls to the agent where the Number of Samples parameter controls the number of samples included in the calculation of the average.

Causes

An unhealthy state indicates the percentage of query cache prunes is high. The query cache might not have enough storage for recently used queries. The query cache limit for individual queries may be too high causing more pruning.

Resolutions

To address high query prune percent increase the query_cache_size to allow additional queries to be stored. Decreasing query_cache_limit can allow more queries to fill up the query cache before a prune.

External References
This monitor does not contain any external references.

See Also for Open Source Software Preview Management Pack


Downloads for Open Source Software Preview Management Pack

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