From owner-freebsd-net@FreeBSD.ORG Sun Jun 17 18:44:49 2007 Return-Path: X-Original-To: net@freebsd.org Delivered-To: freebsd-net@FreeBSD.ORG Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 266B616A47A for ; Sun, 17 Jun 2007 18:44:49 +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 2353313C4BD for ; Sun, 17 Jun 2007 18:44:47 +0000 (UTC) (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 87C3646E6B; Sun, 17 Jun 2007 14:19:07 -0400 (EDT) Date: Sun, 17 Jun 2007 19:19:07 +0100 (BST) From: Robert Watson X-X-Sender: robert@fledge.watson.org To: "M. Warner Losh" In-Reply-To: <20070617.114133.778151882.imp@bsdimp.com> Message-ID: <20070617191609.F33679@fledge.watson.org> References: <20070617.114133.778151882.imp@bsdimp.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: net@freebsd.org Subject: Re: Issue with huge numbers of connections X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 17 Jun 2007 18:44:49 -0000 On Sun, 17 Jun 2007, M. Warner Losh wrote: > I have a friend who is having problems with a service he's running. He gets > billions and billions of connections to this service a day. Somewhere > between 10^8 and 10^9 connections, he notices that his servers lose the > ability to accept new connections. These are TCP connections. > > This is with FreeBSD 6.1R. My first question is: does anybody know if the > fixes to -current/7.0 have fixed this? Is there a fix that can be back > ported? He's currently working around the problem by having a number of > different machines that reboot in a round robin fashion, but would like a > better solution. I think we'll need some more detailed information to make headway. What does "Lose the ability to accept new connections" mean, and how firmly is it meant? Are we talking about "If you restart the application, it comes back" or "Reboot reuiqred", "SYNs don't get SYN/ACK's" or "SYNs get RSTs", or what exactly? There's a lot of scope for exploration, and plenty of bug fixes in the tree, but it's hard to say whether any apply without a bit more detail. Robert N M Watson Computer Laboratory University of Cambridge