Massive operations on Heap

I had a strange problem with my Vaadin Application in production environment.
The system (tomcat 7, vaadin, ajp) was running for two weeks without any problems.
But today I got a serious performance hit - opening a form with about 20 Fields took 20-30 seconds - and I mean an empty form, no data is retrieved from database.

VisualVM showed massive operations on the heap whenever I opened a form. Several hundreds of megabytes (!) of heap space where consumed and immediately garbage collected - and this several times for the request.Therefore the cpu was under heavy load which caused the performance problem. Only a restart of the application helped to solve this.
There doesn’t seem to be a memory leak cause all this stuff (couldn’t even determine what was written to the heap) was immediately collected. A heap dump didn’t show anything that could explain the behavior.

Anybody ever had such a problem? Any hints?



I encountered this problem few days ago (huge heap, OOM , restart the whole thing over and over again) but after I updated the vaadin’s nightly built to the latest, it doesn’t seem to happen anymore. hope that helps.