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1. Re: High CPU Utilization While JBoss Idle
tweise May 25, 2006 6:31 PM (in response to burakbayramli)We are investigating a similar issue with different setup (Apache2/mod_jk 1.2.15, JBoss 3.2.7, jdk 1.5.0_06)
During testing with jmeter our server is busy but we don't get the app throughput we expect. We have a 4 CPU box and top shows all of them 90+ % busy.
HPROF reports what we perceive to be excessive time spent in socket reading, with cpu=samples:
rank self accum count trace method
1 87.00% 87.00% 29123554 302080 java.net.SocketInputStream.socketRead0
2 7.24% 94.24% 2424866 300748 java.net.PlainSocketImpl.socketAccept
3 1.49% 95.73% 497744 301511 java.net.SocketInputStream.socketRead0
4 0.90% 96.63% 301177 302061 java.net.PlainSocketImpl.socketAccept
cpu=samples is not conclusive as far as the net CPU time spent goes, but with cpu=times we still see ~ 50 time spent on these calls.
Our server is not running at capacity, bot worker threads and connetion pool is underutilized.
Has anyone made similar observations?
Thomas -
2. Re: High CPU Utilization While JBoss Idle
clebert.suconic May 26, 2006 12:13 AM (in response to burakbayramli)a thread dump is going to be more useful in your case (idle).
If this is true (the sockets consuming time), something must be wrong in your OS configuration, as a socket accept or socket read shouldn't take any CPU time at al.
Use some OS tools to figure out what's going on in your OS.