JBoss apps only get Full GCs
schwec Aug 12, 2003 12:02 PMI have run into a GC issue while configuring an application to run on Jboss. It looks like once the application has started it pretty much will exclusively Full GC. I initially attributed this to the way the application ran and figured some memory tuning was in order. I made sure I had enough heap, space in the new/old/perm generations, etc. I have since gone through all the VM tuning knobs I could find without luck.
My next step was to isolate some component in my application which might trigger such activity. This led me to strip out all the application pieces and extra Jboss deployments until I was left with only the initial jboss-service.xml. Based on this I determined that a piece in there is causing this behavior, but I am unable to isolate it.
The example output I include below indicates the Full GCs I am seeing. When I have my application deployed and running this problem is exacerbated and leads to 10+ sec Full GC's roughly every minute or two after the application has started. Those Full GC's are a major throughput/performance hit which I need to solve before I can continue with this deployment.
I am including log output and my jboss-service.xml (as an attachment) for background. Any insight would be helpful.
Jboss: ver 3.0.6 (bundled w/Tomcat 4.1.18)
VM: Sun 1.3.1_05
extra cmd line tuning args: -Xms64M -Xmx600M -XX:MaxNewSize=200M -XX:NewRatio=2 -Xnoclassgc -verbose:gc -verbose:class -verbose:jni -XX:MaxPermSize=128M
Log Output:
20030812 12:45:03:020; INFO; org.jboss.deployment.MainDeployer; org.jboss.logging.Logger; [ main ]; Deployed package: file:/home/.../jboss/conf/jboss-service.xml
[Loaded org.jboss.system.server.ServerImpl$1]
20030812 12:45:03:026; INFO; org.jboss.system.server.Server; org.jboss.logging.Logger; [ main ]; JBoss (MX MicroKernel) [3.0.6 (CVSTag=JBoss_3_0_6 Date=200301260037)] Started in 0m:8s:802ms
[Dynamic-linking native method java.lang.Runtime.gc ... JNI]
[Full GC 2646K->1375K(64832K), 0.1425423 secs]
[Full GC 1391K->1375K(64832K), 0.1296706 secs]
[Full GC 1391K->1375K(64832K), 0.1275555 secs]
[Full GC 1391K->1331K(64832K), 0.1892810 secs]
[Full GC 1348K->1331K(64832K), 0.1315105 secs]
[Full GC 1348K->1331K(64832K), 0.1226858 secs]
[Full GC 1348K->1331K(64832K), 0.1253095 secs]
[Full GC 1348K->1331K(64832K), 0.1218643 secs]
[Full GC 1348K->1331K(64832K), 0.1366476 secs]
[Full GC 1348K->1331K(64832K), 0.1274152 secs]
[Full GC 1348K->1331K(64832K), 0.1233673 secs]
[Full GC 1348K->1300K(64832K), 0.1345630 secs]
[Full GC 1316K->1300K(64832K), 0.1347744 secs]
[Full GC 1316K->1300K(64832K), 0.1273432 secs]
[Full GC 1316K->1300K(64832K), 0.1548435 secs]