Computationally intensive scala process using actors hangs uncooperatively

I have a computationally intensive scala application that hangs. By hangs I means it is sitting in the process stack using 1% CPU but does not respond to kill -QUIT nor can it be attached via jdb attach.

Runs 2-12 hours at 800-900% CPU b开发者_JS百科efore it gets stuck The application is using ~10 scala.actors.

Until now I have had great success with kill -QUIT but I am bit stumped as to how to proceed.

The actors write a fair amount to stdout using println which is redirected to a text file but has not been helpful so far diagnostically. I am just hoping there is some obvious technique when kill -QUIT fails that I am ignorant of. Or just confirmation that having multiple actors println asynchronously is a real bad idea (though I've been doing it for a long time only recently with these results) Details scala 2.8.1 & 2.8.0 mac osx 10.6.5 java version "1.6.0_22"

Thanks

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if you just wanna remove the process from the run queue, the obvious choice is

kill -9

Of course you wanna avoid having to do that in the first place, but you do not provide any information that would allow us to help you with that. Writing to stdout in multiple actors is indeed a bad idea, but the worst thing that could come from that is garbled output.

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Most times I have seen the JVM react like that is when it goes into no permgen space. It will then be incapable of anything (even dying). You don't find any traces of that in your printout? Have you tried to increase the permgen space?