I’m writing an App Engine Java application in Eclipse. So far, it has been just playing with datastore and JDO, the application doesn’t do anything serious. However after about an hour of developing I end up with java.lang.OutOfMemoryError error.
I’ve read that this error is most likely caused by some kind of memory leak. For testing I tried to speed up things a little bit and force the error to appear. Using wget I made around 3000 request to the same urls as during the development in Eclipse. But nothing happened. I assume that if there was really a memory leak, I would see it this way…
Is it possible hat this error is really caused by the development process? I use the trick with touching appengine-web.xml, so every time I change and save a file the server loads all files again and runs DataNucleus enhancer… so it happens very often, could this be the reason?
Another thing is that it probably started after I implemented following solution ( How to use JDO persistence manager?) for working with Persistence Manager. I store the reference to PM in several places during the request but it all should get disposed after the request is finished right? And again, if it was caused by this, wouldn’t the error occur after 3000 requests? (Which is way more request than during an hour of development).
I don’t want to leave this question unanswered, so this is extracted from the comments below the questions:
Yes, PermGen error could be caused by frequent redeployment during the development process. So the app doesn’t necessary have to have a memory leak.