# Case Study Cluster Status (B)

+ Cluster Duration
  + Grafana Monitoring TiDB —> Query Summary —> Duration 
  + The overall delay of 999 lines is not high, basically around 8ms


![left](./student-guide/diagram/27-cluster-situation-02-01.png)

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The 95th-percentile, 95th percentile percentile refers to the number in the given set that exceeds 95% of it. It's a statistical concept. For an interface, it is useful to accurately count its traffic, and it can pick up some accidental outliers. The 95th percentile is the highest value used for statistics, and more than 5% of the data will be discarded. This removes instantaneous burrs (spikes) and makes statistical averages more realistic. For example, the data collected were 60,45,43,21,56,89,76,32,22,10,12,14,23,35,45,43,23,23,23,43,23 (20 points). Place the sequence in descending order, with a maximum value of 89. Since 5% of 20 points is 1, we discard the 1 maximum value of 89. The maximum remaining 76 is what we call the 95th percentage point