# Monitoring Analysis (D)

+ Grafana Monitoring TiDB —>`Query Detail - Duration 999/99/95/80 by Instance`
  + 999 Duration jitter on multiple TiDB Servers


![left](./student-guide/diagram/03-08-1.png)

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Having confirmed that there is a reads and writes problem, the next step is to check which step went away.Grafana Monitoring TiDB —> Query Detail - Duration 999/99/95/80 by Instance Monitoring You can see how long it took (in different percentiles) to execute SQL statement for each TiDB instance.In Problem Time 17:12 Query Detail - Duration 999/99/95/80 by Instance: Performance jitter occurs for 999 Duration of multiple TiDBs, and the probability of multiple TiDB Servers having problems at the same time is very small, so troubleshooting the problem TiDB Server .