From owner-freebsd-net Mon Jun 3 10:12:15 2002 Delivered-To: freebsd-net@freebsd.org Received: from patrocles.silby.com (d101.as15.nwbl0.wi.voyager.net [169.207.134.229]) by hub.freebsd.org (Postfix) with ESMTP id DCB4137B406 for ; Mon, 3 Jun 2002 10:12:06 -0700 (PDT) Received: from patrocles.silby.com (localhost [127.0.0.1]) by patrocles.silby.com (8.12.3/8.12.3) with ESMTP id g53HDaOA038456; Mon, 3 Jun 2002 12:13:36 -0500 (CDT) (envelope-from silby@silby.com) Received: from localhost (silby@localhost) by patrocles.silby.com (8.12.3/8.12.3/Submit) with ESMTP id g53HDWTD038453; Mon, 3 Jun 2002 12:13:34 -0500 (CDT) X-Authentication-Warning: patrocles.silby.com: silby owned process doing -bs Date: Mon, 3 Jun 2002 12:13:32 -0500 (CDT) From: Mike Silbersack To: Nguyen-Tuong Long Le Cc: freebsd-net@freebsd.org Subject: Re: Problem with SYN cache in FreeBSD 4.5 In-Reply-To: Message-ID: <20020603121118.Y38431-100000@patrocles.silby.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On Mon, 3 Jun 2002, Nguyen-Tuong Long Le wrote: > Hi all, > > Our group has a proprietary web server that can handle 10000 requests/s > under FreeBSD 4.3 release. We recently upgraded our system to 4.5 and got > very poor performance. While the web server runs, I see lots of messages > similar to the following on the console > "Limiting open port RST response from 1068 to 200 packets per second". > > The problem seems to be related to the syncache implementation > that drops incoming SYN segments. I've tried to increase the size of > the hash table but that didn't seem to help much. Here is the output > of "sysctl net.inet.tcp.syncache". A few questions: 1. Is this 4.5-release, or 4.5-stable (aka 4.6-RC2)? 4.5-release had a few bugs in the syn cache which could cause crashes. 2. Are you using accept filters? Accept filters act oddly on 4.5-release, you'll have to upgrade to 4.5-stable/4.6. 3. Could you use tcpdump to determine what exactly is going wrong and post a url to the log so that we can investigate what is going wrong? Thanks, Mike "Silby" Silbersack To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message