From owner-freebsd-net Thu Mar 25 14: 3:36 1999 Delivered-To: freebsd-net@freebsd.org Received: from leaf.lumiere.net (leaf.lumiere.net [207.218.152.15]) by hub.freebsd.org (Postfix) with ESMTP id 358AE14D21; Thu, 25 Mar 1999 14:03:35 -0800 (PST) (envelope-from j@leaf.lumiere.net) Received: (from j@localhost) by leaf.lumiere.net (8.9.2/8.9.1) id OAA00423; Thu, 25 Mar 1999 14:03:08 -0800 (PST) Date: Thu, 25 Mar 1999 14:03:08 -0800 (PST) From: Jesse To: Luigi Rizzo Cc: freebsd-net@FreeBSD.ORG, freebsd-hackers@FreeBSD.ORG Subject: Re: 3.1-STABLE dies on 40+ connects In-Reply-To: <199903251903.UAA13471@labinfo.iet.unipi.it> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > 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) 0 requests for memory denied 0 requests for memory delayed 0 calls to protocol drain routines 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) 0 requests for memory denied 0 requests for memory delayed 0 calls to protocol drain routines So it definitely appears to be an mbuf issue. 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.. 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? Lastly, is it safe to raise my nmbclusters higher than 4096? Like 10000? What are the downsides? --- Jesse http://www.lumiere.net/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message