From owner-freebsd-hackers@FreeBSD.ORG Thu Jun 22 11:58:53 2006 Return-Path: X-Original-To: freebsd-hackers@freebsd.org Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id B602216A47C for ; Thu, 22 Jun 2006 11:58:53 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from cyrus.watson.org (cyrus.watson.org [209.31.154.42]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6C59043D58 for ; Thu, 22 Jun 2006 11:58:51 +0000 (GMT) (envelope-from rwatson@FreeBSD.org) Received: from fledge.watson.org (fledge.watson.org [209.31.154.41]) by cyrus.watson.org (Postfix) with ESMTP id CBAEC46BC9; Thu, 22 Jun 2006 07:58:49 -0400 (EDT) Date: Thu, 22 Jun 2006 12:58:49 +0100 (BST) From: Robert Watson X-X-Sender: robert@fledge.watson.org To: Steven Hartland In-Reply-To: <006901c695a0$e1978f30$b3db87d4@multiplay.co.uk> Message-ID: <20060622125720.K35204@fledge.watson.org> References: <006901c695a0$e1978f30$b3db87d4@multiplay.co.uk> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: freebsd-hackers@freebsd.org Subject: Re: Massive apache slowdown after high load period X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 22 Jun 2006 11:58:53 -0000 On Thu, 22 Jun 2006, Steven Hartland wrote: > We've just had a box which was subjected to a large amount of small apache > requests once this subsided the response of apache was still very slow. Many > seconds between requests showing in tcpdump and response being returned. > > Upon investigation it seemed the number of sockets in teardown / mbufs > allocated might be the cause has anyone else experienced that? On 5.x SMP systems, there is a known problem in mbuf memory statistics reporting, which has been corrected in 6.x. The below mbuf counter is probably a property of that known problem, and is likely unrelated to the slowdown you have experienced. Robert N M Watson Computer Laboratory University of Cambridge > > netstat -m > 4294880568 mbufs in use > 29885/76800 mbuf clusters in use (current/max) > 0/5/6656 sfbufs in use (current/peak/max) > 38088 KBytes allocated to network > 0 requests for sfbufs denied > 0 requests for sfbufs delayed > 0 requests for I/O initiated by sendfile > 687 calls to protocol drain routines > > netstat showed > 1 CLOSE_WAIT > 6 LAST_ACK > 41 FIN_WAIT_1 > 129 FIN_WAIT_2 > 295 ESTABLISHED > 1083 TIME_WAIT > > A restart of apache made no difference a reboot > of the machine was required to return normal > performance. > > N.B. 5.4-RELEASE-p8 is in use on the machine in > question. > > Steve > > > ================================================ > This e.mail is private and confidential between Multiplay (UK) Ltd. and the > person or entity to whom it is addressed. In the event of misdirection, the > recipient is prohibited from using, copying, printing or otherwise > disseminating it or any information contained in it. > In the event of misdirection, illegible or incomplete transmission please > telephone +44 845 868 1337 > or return the E.mail to postmaster@multiplay.co.uk. > > _______________________________________________ > freebsd-hackers@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-hackers > To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org" >