Questions about negative loaded classes ...
vladimir.x.ivanov at oracle.com
Tue Oct 3 12:10:17 UTC 2017
> 1. On more than half of the machines (200 out of 400 machines), we see he
> JMX counter report negative LoadedClassCount, see attached jmxcounter.png.
> After some further dig, we note UnloadedClassCount is larger than
> TotalLoadedClassCount. And LoadedClassCount (-695,710) =
> TotalLoadedClassCount - UnloadedClassCount . PerfCounter reports the same
> number, here is the result on the same machine:
> $ jcmd 307 PerfCounter.print | grep -i class | grep -i java.cls
JVM performance counters aren't exact (e.g., updates aren't atomic ),
so I wouldn't be surprised to see loadedClasses & unloadedClasses
diverging during concurrent class loading.
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