[jboss-user] [JBoss Seam] - Seam apps leaking memory?!

[stephen.friedrich]

My (not so large) app can be redeployed on JBoss 4.0.5 exactly two times before the deployment is failing.

I know that the issue of OOME in PermGenSpace has been discussed before and the default answers were either "Sun JVM bug", "use jrockit" (which only increases the available redeploys a little without really solving the problem) or "increase perm space" (dito, I manage up  to four redeploys).

I don't really buy any of thse answers because other apps do not have such severe problems.
Here's a nice summary:
http://opensource.atlassian.com/confluence/spring/pages/viewpage.action?pageId=2669

Using Yourkit I tried to investigate the problem:

  | * Started JBoss.
  | * Deployed the booking app.
  | * Undeployed the booking app.
  | * Looked at instances of org.jboss.seam.* classes.
  | 

I have found these two problems:

  | *  java.beans.Introspector leaks if flushCaches() isn't called. For testing I added such a call in org.jboss.seam.servlet.SeamListener.contextDestroyed()
  | *  The cache used in javassist's ProxyFactory is never cleared. I updated javassist to version 3.4 and added "ProxyFactory.useCache = false;" to org.jboss.seam.servlet.SeamListener.contextInitialized()
  | I doubt that this is the correct way, but it brought down the instance count and did not seem to break anything. (javassist's ProxyFactory is used from org.jboss.seam.Component.createProxyFactory().)
  | 

These changes reduced the instance count but there are still some objects that refuse to get collected. I am stuck: All references to remaining objects come from the UnifiedClassLoader3. 
Looks like "org.jboss.util.timeout.TimeoutFactory$1" is still holding a strong reference to the class loader.

This is well out of my expertise. I'd really appreciate if somebody could look into that.[/url]

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