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Re: Strange trouble with clamd/greylist/mimedefang

Clint Adams a écrit :
On Sat, Jun 09, 2007 at 08:46:53PM +0200, BERTRAND Joël wrote:
Right. For me, one think is very suspect. Milter-greylist nor clamd are not able to fork on kant.

What makes you think that they're unable to fork?

	Because clamd uses multithread and multitask features.
When mimedefang send a mail to clamd socket, clamd forks itself to analyze this mail. On kant, clamd is not able to fork, or maybe is able to fork but cannot analyze any mail, and mimedefang aborts with a "busy timeout". If I replace clamd by clamscan, mimedefang works (but alayze process take a very long time). When I try to replace clamscan by clamdscan that uses clamd, mimedefang hangs after a very short number of analyzes.

	Maybe clamd implementation is broken with libc6 2.5.

	The only significative difference for me is the libc release.

Root kant:[~] > dpkg-query -l libc6
ii  libc6          2.5-9          GNU C Library: Shared libraries

rayleigh:[~] >  dpkg-query -l libc6
ii  libc6          2.3.6.ds1-13   GNU C Library: Shared libraries

2.5 gives you NPTL, which means that threaded programs can have real
threads instead of forking.

If you do a ps -eLf on a glibc2.5 system with numerous clamdscan
processes going, you will hopefully see multiple clamd lines
(same PID, different LWP number).

If you don't, maybe there's an issue with libpthread.

I see some clamd threads, but even with some threads, clamd cannot analyze inbound mails.

I have another question about threads. On a U80, with four UltraSparc processors, are two threads of one process limited to ressources given by one processor, or can they be shared on two processors (like regular process) ?



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