PermGen with -server option

Question

Hello all. I have quite a trouble with JVM:
We're developing a multimodule web application. Modified wars (=modules) are sent from continuous integration server to our development JBoss many times a day - this redeploys modified WAR. The same for clients - we'd like to redeploy single modules without restarting the server.
Unfortunately after few redeploys we get PermGen space. Server is useless and must be restarted.
1) When JVM started with -client option I can avoid PermGen space, but from time to time (~1/10 redeploys), I get this:
Cause: Class 'org.richfaces.renderkit.html.SuggestionBoxRenderer' is missing a runtime dependency: java.lang.NoClassDefFoundError: org/ajax4jsf/renderkit/compiler/ElementBase$1
at com.sun.faces.config.ConfigManager.initialize(ConfigManager.java:213)
at com.sun.faces.config.ConfigureListener.contextInitialized(ConfigureListener.java:196)
at org.jboss.web.jsf.integration.config.JBossJSFConfigureListener.contextInitialized(JBossJSFConfigureListener.java:69)
I need to restart redeploy. After few redeploys this error repeats.
A bug in JVM or JBoss, or do I need to add some magical command line options for JVM?
2) With -server option I still have PermGen space, because JVM doesn't call finalize() methods on objects. Finalization queue is big.
Is there any JVM option for enabling finalization in -server mode (except manual calling System.runFinalization()), or this is a bug in JVM?
3) According to -XX:+TraceClassUnloading, JVM unloads unused classes only when PermGen memory is full. Lots of unused classes from WEB-INF/lib are kept in memory for long time. Couldn't this unloading be done earlier?
Any ideas? My JVM version is 1.6.0_10.

Answer 1

And another thing I don't understand with -server option. Sometimes instead of throwing PermGen, the application is frozen by GC. But even weak references to some objects aren't removed, for example:
Class Name | Ref. Objects | Shallow Heap | Ref. Shallow Heap | Retained Heap
class java.lang.reflect.Proxy @ 0x3fd83b8 System Class | 1 | 40 | 120 | 58 504
'- loaderToCache java.util.WeakHashMap @ 0x8cf8ad8 | 1 | 48 | 120 | 41 312
'- table java.util.WeakHashMap$Entry[128] @ 0xa2e3fe8 | 1 | 528 | 120 | 41 232
'- [43] java.util.WeakHashMap$Entry @ 0xa9e0390 | 1 | 40 | 120 | 2 344
'- referent org.jboss.mx.loading.UnifiedClassLoader3 @ 0xa89a360| 1 | 120 | 120 | 1 636 912
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