MMU drops suddenly

Sundara Mohan M m.sundar85 at gmail.com
Fri Nov 15 18:55:38 UTC 2019


Hi,
    Have noticed following in gc log
[2019-11-13T19:24:13.095+0000][69629.984s][info][gc,mmu      ] GC(10952)
MMU: 2ms/0.0%, 5ms/0.0%, 10ms/23.7%, 20ms/61.9%, 50ms/81.7%, 100ms/90.8%
[2019-11-13T20:12:55.339+0000][72552.228s][info][gc,mmu      ] GC(11441)
MMU: 2ms/0.0%, 5ms/0.0%, 10ms/23.7%, 20ms/61.9%, 50ms/81.7%, *100ms/90.8%*
[2019-11-13T21:00:53.415+0000][75430.304s][info][gc,mmu      ] GC(11927)
MMU: 2ms/0.0%, 5ms/0.0%, 10ms/0.0%, 20ms/0.0%, 50ms/44.2%, *100ms/70.7%*
[2019-11-13T21:52:46.244+0000][78543.133s][info][gc,mmu      ] GC(12450)
MMU: 2ms/0.0%, 5ms/0.0%, 10ms/0.0%, 20ms/0.0%, 50ms/44.2%, 100ms/70.7%
[2019-11-13T22:40:35.887+0000][81412.776s][info][gc,mmu      ] GC(12946)
MMU: 2ms/0.0%, 5ms/0.0%, 10ms/0.0%, 20ms/0.0%, 50ms/44.2%, 100ms/70.7%
[2019-11-13T23:27:23.807+0000][84220.696s][info][gc,mmu      ] GC(13410)
MMU: 2ms/0.0%, 5ms/0.0%, 10ms/0.0%, 20ms/0.0%, 50ms/0.0%, *100ms/43.0%*

Was trying to understand what it means and here is my understanding, This
says how much minimum CPU available for mutator thread in last Xms
1. Is this correct?
2. Why is this suddenly dropping from (100ms 90% -> 40%) ? Also other time
unit it is 0% does that mean my application doesn't get a chance to run?
Also i see it never goes back to higher value.
3. Does this measure indicates something good or bad?
3. If this is bad what should i look further to get more insights?

Can someone help me to get better understanding on this.


TIA,
Sundar


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