Java Garbage Collector - Not running normally at regular intervals

Question

I have a program that is constantly running. Normally, it seems to garbage collect, and remain under about 8MB of memory usage. However, every weekend, it refuses to garbage col

Answer 1

Ok guys, thanks for all your help. The correct answer however, turned out to have nothing to do with the program itself.

It seems that at the time that the memory usage started it's steady climb, the server was synchronising it's time from somewhere internal, though our client's IT contact has no idea where. Obviously, wherever it was coming from, was not a good clock, since the time was half an hour behind. We turned off this synchronisation, and now that I have checked it again this morning, the problem did not occur. So if the time on your system suddenly changes, apparently this causes problems for the garbage collector. At least that's what this implies to me.

As for why this wasn't occuring on any other parts of our system on this server (which are also written in Java), we probably simply haven't noticed, as they don't deal with as large a number of objects, and so they would never have hit their out of memory state.

I find this strange, since I would have thought that the invoking of the garbage collector would be completely related to memory usage, and not on the system time at all. Clearly, my understanding of how the garbage collector works is woefully inadequate.