We have a question with repect to the appearance of our JBoss memory consumption in TOP on boxes running CENTOS 3.3. We have set both the JVM min. and max. to 1024 for a particular instance and the TOP snapshot shows memory consumption for our Java process above and below the settings.
We would like to allocate a fixed block of memory to the JVM initially and avoid dynamic resize.
In this configuration we notice that the memory allocated by the JVM keeps on growing beyond the max size of 1024m up to 2GB! The JBoss console in parallel reports growing free memory, eventually the JVM runs out of memory.
When we switch back to -Xms512m -Xmx1024m everything works fine. During automated tests the JVM allocated memory never exceeds the initial 506MB with ~ 300MB free (according to the JBoss console).
Any information as to why this is would be greatly appreciated.