From owner-freebsd-net@FreeBSD.ORG Mon Nov 10 02:41:56 2003 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 05BD816A4CE; Mon, 10 Nov 2003 02:41:56 -0800 (PST) Received: from westhost42.westhost.net (westhost42.westhost.net [216.71.84.238]) by mx1.FreeBSD.org (Postfix) with ESMTP id CB2B443FA3; Mon, 10 Nov 2003 02:41:54 -0800 (PST) (envelope-from mini@freebsd.org) Received: from [172.16.0.241] (mulder.f5.com [205.229.151.150]) by westhost42.westhost.net (8.11.6/8.11.6) with ESMTP id hAAAfrl27235; Mon, 10 Nov 2003 04:41:53 -0600 In-Reply-To: <3FAF5CD9.ADA58CAF@pipeline.ch> References: <3FAE68FB.64D262FF@pipeline.ch> <3FAEC407.F10E7BA@pipeline.ch> <3FAF5CD9.ADA58CAF@pipeline.ch> Mime-Version: 1.0 (Apple Message framework v606) Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: <823BFED0-136A-11D8-87D8-000A95CD3CF8@freebsd.org> Content-Transfer-Encoding: 7bit From: Jonathan Mini Date: Mon, 10 Nov 2003 02:41:57 -0800 To: Andre Oppermann X-Mailer: Apple Mail (2.606) cc: mb@imp.ch cc: freebsd-current@freebsd.org cc: ume@freebsd.org cc: sam@errno.com cc: freebsd-net@freebsd.org Subject: Re: tcp hostcache and ip fastforward for review X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 10 Nov 2003 10:41:56 -0000 On Nov 10, 2003, at 1:39 AM, Andre Oppermann wrote: > Jonathan Mini wrote: > > All in all I don't think it is worth adding this complexity. I agree. >> This is actually a small value for TCP connections which are being >> used to forward messages, especially on gigabit links. >> Heavily-intensive >> web applications that are using small HTTP requests (pipelined inside >> a >> persistent connection) to update small manipulations of state are >> a good example of this. I wouldn't be surprised to see chatter >> between SQL servers follow similar patterns. Applications which >> use XML-based messaging often send several small packets per message, >> which is unfortunate. > > Do you think such applications manage to send 1000 packets per second > with less than 256 bytes payload per packet? I think the network code > would collect some data to form a larger packet (unless TCP_NODELAY > set)? Traffic like that only happens when TCP_NODELAY is set. Otherwise, you get what you would expect. >> On the other hand, I'm used to looking at proxies, which are not >> the general case. This is why the limits are tunable, after all. =) > > Is there way you could monitor such connections and compile some > statistics how many small packets per second are sent? I could adjust > the patch to just report the fact instead of dropping the connection. > Could do it for 4.9-R too, it's fairly easy. Alas, no. This is from anecdotal experience from our support staff at work. -- Jonathan Mini mini@freebsd.org http://www.freebsd.org