heap use increase moving from JBossAS 4.2 to 5.0.1

[gwilder]

I have a deployment consisting of 2 large ear applications, each with 4 wars, each war with ~160 jars; and 2 small ear files, each with 1 war, each war with ~ 50 jars. (total 10 webapps).

When deployed on a 32-bit Windows machine running Sun JDK 5 using JBoss AS 4.2, startup and servlet init's of apps take 5 minutes and approximately 200M of Heap.

When deployed using JBossAS 5.0.1 and JDK 5 or 6 on same 32-bit hardware, startup and servlet init's take 12 minutes and approcimately 800M of Heap.

Is there a means to tune JBossAS 5.0.1 to use less heap? If not, I am forced to alter potential deployment topologies for additional applications which I used to deploy on the same jvm with JBoss 4.2. (I have 5 more apps that I used to deploy on 4.2 but cause painful garbage collection leading to OOME's in 5.0.1.

[dimitris]

AS5 keeps a lot more metadata for the deployed objects, plus it mediates access to the filesystem through an extra layer (VFS), so that increases the memory requirements.

Is it possible to attach a profiler (e.g. JBoss Profiler) and post your findings? i.e. where most of the time is spent plus the classes with the most objects, etc.

[dimitris]

I've created this JIRA issue if you want to attach your findinds:

https://jira.jboss.org/jira/browse/JBAS-6549