Date: Thu, 25 Mar 1999 16:32:58 -0500 (EST) From: Bill Fumerola <billf@chc-chimes.com> To: Jesse <j@lumiere.net> Cc: freebsd-net@FreeBSD.ORG, freebsd-hackers@FreeBSD.ORG Subject: Re: 3.1-STABLE dies on 40+ connects Message-ID: <Pine.HPP.3.96.990325163030.7134I-100000@hp9000.chc-chimes.com> In-Reply-To: <Pine.BSF.4.05.9903251359140.338-100000@leaf.lumiere.net>
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[ this really shouldn't be x-posted ] On Thu, 25 Mar 1999, Jesse wrote: > > i trust you -- i suspect there is some piece of the code somewhere > > which does not check for mcopy/mpullup/etc failures. > > > > in fact it would be nice to know if there is some reproducible way to > > trigger these crashes because i think this is a problem that ought to > > be fixed in a better way than overallocating resources. > > Okay, I updated the NMBCLUSTERS to 4096. This allowed me to get 40 clients > on successfully. Here's an netstat -m with 40 clients connected: > > leaf:~# netstat -m > 1076/1792 mbufs in use: > 1025 mbufs allocated to data > 51 mbufs allocated to packet headers > 1023/1620/4096 mbuf clusters in use (current/peak/max) > 3464 Kbytes allocated to network (62% in use) Wow that's high. > > So I tried 60 clients. It crashed after the 56 client connected. I was > doing netstat -m the entire time until the moment it crashed. The last one > showed: > > leaf:~# netstat -m > 4637/4704 mbufs in use: > 4565 mbufs allocated to data > 72 mbufs allocated to packet headers > 4564/4604/4096 mbuf clusters in use (current/peak/max) > 9796 Kbytes allocated to network (99% in use) Crunch. > So it definitely appears to be an mbuf issue. Definitely. Could you get some statistics on mbuf/client, for instance, which we could use to determine if the climb is linear or exponential. > Is it normal for something to use mbuf's so quickly? Each client is being > sent a 128kbps stream. I know sites like ftp.cdrom.com transfer MUCH more > than this per second.. soo.. This is certainly a bug of some sort. > It'd of course be nicer to see FreeBSD be 'fixed' to not crash in this > situation, but is there anything that the authors of icecast can do to > help reduce their mbuf usage? Does the machine panic or just crash, that would at least be the first step is just to get FreeBSD to panic. > Lastly, is it safe to raise my nmbclusters higher than 4096? Like 10000? > What are the downsides? Death or memory problems I can't remember which. - bill fumerola - billf@chc-chimes.com - BF1560 - computer horizons corp - - ph:(800) 252-2421 - bfumerol@computerhorizons.com - billf@FreeBSD.org - To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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