From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261321AbTJHCKY (ORCPT ); Tue, 7 Oct 2003 22:10:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261434AbTJHCKX (ORCPT ); Tue, 7 Oct 2003 22:10:23 -0400 Received: from cpe-024-165-190-126.midsouth.rr.com ([24.165.190.126]:34772 "EHLO groundzero.enchanted.net") by vger.kernel.org with ESMTP id S261321AbTJHCKS (ORCPT ); Tue, 7 Oct 2003 22:10:18 -0400 From: Aaron Wrasman Date: Tue, 7 Oct 2003 21:10:18 -0500 To: linux-kernel@vger.kernel.org Subject: Slow network and initial TCP connection Message-ID: <20031008021018.GA17457@enchanted.net> Reply-To: wrasman@cs.utk.edu Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="Nq2Wo0NMKNjxTN9z" Content-Disposition: inline X-Url: http://www.cs.utk.edu/~wrasman User-Agent: Mutt/1.5.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --Nq2Wo0NMKNjxTN9z Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable I'm working with a 2.4 kernel and we have linux servers (over 3000) that ha= ve=20 to talk over a slow satellite connection. We noticed that it was timing out on the initial TCP connection and had to retry. Between the first time out and the second try with a longer timeout it was actually taking longer than it use to with a different OS and we had more traffic on our network because of the retry. We changed one thing in include/linux/tcp.h Change: #define TCP_TIMEOUT_INIT ((unsigned)(3*HZ)) to be #define TCP_TIMEOUT_INIT ((unsigned)(5*HZ)) We did this and connections work the first time and we cut our traffic in half. Is there a better way than having to hardcode this in a header file and having to recompile the kernel? I would have thought someone would have run into this on a high latency network before now and this would be tuneable from /proc I know that there are some socket options that an application can set to override this in some places but I need to do this for all TCP traffic. All suggestions? --Nq2Wo0NMKNjxTN9z Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.3 (GNU/Linux) iD8DBQE/g3IK4d99qqyIJKERAkx4AJ91gZOJXcQDDOQbevxrCJ+FFzKKPwCdHbLK ///o4y8uhv2vaSjGpbuGy80= =ruT0 -----END PGP SIGNATURE----- --Nq2Wo0NMKNjxTN9z--