Just to add to Pete’s note, I didn’t see anything in s.filipowicz’s note that said he was running 32-bit, so let’s clarify to readers that Pete’s first 2 sentences refer to that specifically. (His third sentence implies it, but I just want to be clear.)
Also, s.filipowicz, you say you got “outofmemory” errors, but you don’t say what kind. There is a big difference between an OOM error that then says it’s related to “heap space”, versus one that says it’s related to “permgen”, or “out of swap space”, or “unable to create new native thread”. The latter three may well mean that you need to lower the heap, believe it or not.
Sometimes, the higher the heap the greater the contention with other things that leads especially to the “out of swap” or “new native thread” error. The “permgen” error generally means you need to increase the maxpermsize, but that’s not always clear—sometimes you need to fix the problem that’s stressing the permgen.
And indeed, you say that lowering the heap max made the errors go away, but performance got bad. One may suspect that you were then having something other than an “OOM heap space” error, and that lowering the heap made that go away. But then it could just be that whatever caused that error then is not happening since you restarted—and it may come back, so you may well still need to increase the heap.
Sadly, this subject is a lot more complex than you will generally find discussed on most blogs and even many Java resources. I started to address it as a blog entry here:
CF911: Lies, damned lies, and when memory problems not be at all what they seem, Part 1
http://www.carehart.org/blog/client/index.cfm/2010/11/3/when_memory_pr oblems_arent_what_they_seem_part_1
While I never have finished the additional parts of a series I had anticipated, the introductory info there (fairly substantial) may still be of value.
Anyway, as a starting point, the key is to note which kind of OOM error you are getting when CF crashes, which as you may have found are discussed in the logs in the Re: JVM Heap size settings\runtime\logs\ dir (or Re: JVM Heap size settings\logs\), not the Re: JVM Heap size settings\logs viewable in the CF admin. Let us know what you find.
/charlie
