[FLINK-16721] getProcessCpuLoad seems to report a wrong cpu load

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Cannot Reproduce
• Affects Version/s: 1.10.0
• Component/s: Runtime / Metrics
• Assignee: Unassigned
• Reporter: xiaogang zhou
• Created: 23/Mar/20 11:25
• Updated: 03/Jul/20 09:58
• Resolved: 03/Jul/20 09:58

Description

I am monitoring the flink_taskmanager_Status_JVM_CPU_Load in the prometheus. As there is some random spikes (see attachment in cpu trend), but when i use some tool to get the thread load(using the analytical tool: https://github.com/oldratlee/useful-scripts/blob/master/show-busy-java-threads) , I didn't see any abnormal(see busythreads attachment) 

 

And then I found the issue about mxBean::getProcessCpuLoad in stackoverflow. https://stackoverflow.com/questions/38421242/operatingsystemmxbean-getsystemcpuload-and-getprocesscpuload-values

 some one suggest the metric can be inaccurate in some cases. 

Can anybody help me understand what's going on in my case?