Hi Sven
Like you I wondered about this very annoying issue.
It just got me worked up so much I logged this issue in a bit of a huff. The PermGen issue was happening on a regular basis (every day actually). On the quality Alias I could not get answers. But then someone eventually pointed me to articles (attached in the issue).
The issue should now be a documentation issue from what I can see. Go read those articles and it will example why it is happening. If you feel like it you can vote on it.
https://glassfish.dev.java.net/issues/show_bug.cgi?id=11159
regards
Richard.
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