[jboss-user] [Performance Tuning] - Re: Full Garbage Collection every few seconds – GC frees very little memory (JBoss 4.2.3 with JDK 1.5.0 64-bit)

Peter Johnson [http://community.jboss.org/people/peterj] created the discussion "Re: Full Garbage Collection every few seconds – GC frees very little memory (JBoss 4.2.3 with JDK 1.5.0 64-bit)" To view the discussion, visit: http://community.jboss.org/message/572010#572010 -------------------------------------------------------------- Don't set NewRatio to 1. This means that the young gen and old gen are the same sizes. The JVM will do a full collection if the old gen does not have enough to hold all of the object in the young gen (note I wrote 'all', and not 'alive', the determination of whether to do a full vs minor collection takesp lace before the JVM figures out how many objects will survive a minor collection).  I recommend setting it to 3 or 4. If you suspect a memory leak, take a heap dump and anlayze it with VisualVM. You might want to gather and plot the GC stastics. See these white papers: Java Garbage Collection Statistical Analysis 101 Java Garbage Collection Performance Analysis 201 at http://www.cmg.org/cgi-bin/search.cgi?q=java+peter+johnson&x=30&y=10 http://www.cmg.org/cgi-bin/search.cgi?q=java+peter+johnson&x=30&y=10 Also, dig through this forum, it contains many tuning suggestions (including more details about using VisualVM and spotting memory leaks) -------------------------------------------------------------- Reply to this message by going to Community [http://community.jboss.org/message/572010#572010] Start a new discussion in Performance Tuning at Community [http://community.jboss.org/choose-container!input.jspa?contentType=1&...]