JAVA_OPTS in run.conf

[mduffy_lists]

Creating the optimal settings for garbage collection and JVM tuning can be over whelming:

http://java.sun.com/javase/technologies/hotspot/gc/gc_tuning_6.html

http://java.sun.com/javase/technologies/hotspot/vmoptions.jsp

We are running JBoss on new Dell servers with 2Gb of memory and we are getting out of memory errors with just moderate usage.

Our current settings are:

JAVA_OPTS="-Xms512m -Xmx1024m -XX:MaxPermSize=256m -XX:-UseGCOverheadLimit -Dorg.jboss.resolver.warning=true -Dsun.rmi.dgc.client.gcInterval=3600000 -Dsun.rmi.dgc.server.gcInterval=3600000"

Any suggestions?

Thx.

Mike

[peterj]

What out of memory exceptions? Out of heap memory? Out of permgen space? Out of system resources/memory? Each is dealt with in a different way. Please post the exact exception.

[mduffy_lists]

javax.servlet.ServletException: Servlet execution threw an exception
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:313)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
 at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:235)
 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
 at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:190)
 at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:92)
 at org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.process(SecurityContextEstablishmentValve.java:126)
 at org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.invoke(SecurityContextEstablishmentValve.java:70)
 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
 at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
 at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:158)
 at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:330)
 at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:828)
 at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:601)
 at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
 at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.OutOfMemoryError: GC overhead limit exceeded

We added -XX:-UseGCOverheadLimit to the JAVA_OPTS but I am not sure that is the optimal solution.

Mike

[peterj]

According to http://java.sun.com/javase/technologies/hotspot/gc/gc_tuning_6.html#par_gc.oom, it would appear that you are running too many collections and each collection is not freeing enough heap space. Have you collected GC data and graphed it to see what is happening? See my presentation on that subject for information:

http://www.cecmg.de/doc/tagung_2007/agenda07/24-mai/2b3-peter-johnson/index.html

Also, I assume you are using JDK 6, if that is not correct, please let me know.