java run out of memory issue

Question

I have a jar file running on an amazon-ec2-m1.large instance with linux 64bit operating system. I run out of memory after different hours, usually between 2-4, although in m

Answer 1

Without trying to decode the dump data, I'll observe that there are basically three cases for running a JVM out of memory:

1. Having a structure (list of lists or whatnot) that is allowed to accumulate masses of unused (but still referenced) data.
2. Leaving various "handles" open -- file handles, threads, data base operations. Especially if using an API with a native component you can potentially leave a lot of stuff outside of the reach of GC.
3. Making a single extremely large request (or a "burst" of such requests).

Kind of in-between here would be classes. If you run a app that dynamically creates and loads classes, you must properly use individual class loaders to make the classes collectable.