Very High CPU usage of OC4J Processes After Migrating To Sun T5240 Server with UltraSPARC T2 Plus Processors
Last updated on FEBRUARY 24, 2017
Applies to:Oracle Containers for J2EE - Version 10.1.2.0.0 to 10.1.3.5.0 [Release AS10gR2 to AS10gR3]
Sun SPARC Sun OS
When running JVM based processes on SUN UltraSPARC T1/T2 processors, the global performance of the JVM is very bad and CPU usage reported by the JVM appears to be abnormally high, while the server is free of resources.
In our specific case, we saw, on Solaris 10, that running Oracle BPEL Application on OAS 10gR2 with JDK HotSpot 1.4.2, the OC4J_BPEL Instance process monitoring showed following information:
- CPU utilization is about 90% (while the expected is much less)
- user/kernel CPU utilization ratio reaches 1/19, (while expected is 4/1)
- The BPEL Application performance was generally bad.
The following commands were used to monitor OC4J
- ($ prstat): To identify high CPU using lightweight processes. Results were something like:
13421 appbpel 3468M 2417M cpu17 0 10 0:54:35 88% java/201
Here we have lightweight process 201 is using 88% CPU and corresponds to a ‘java’ process thread.
- ($ top) with results like:
CPU states: 10.9% idle, 28.0% user, 61.1% kernel, 0.0% iowait, 0.0% swap
user/kernel ratio is 1/2.
The problem appeared during the migration to Sun SPARC T5240 Server.
The target server is multiCPU and has 16 Virtual CPUs assigned to the Solaris Zone where OracleAS 10.1.2 runs.
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