From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 11 May 2001 15:57:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 11 May 2001 15:57:38 -0400 Received: from zeus.kernel.org ([209.10.41.242]:19341 "EHLO zeus.kernel.org") by vger.kernel.org with ESMTP id ; Fri, 11 May 2001 15:57:22 -0400 Content-Type: text/plain; charset=US-ASCII From: Brad Pepers Organization: Linux Canada Inc. To: linux-kernel@vger.kernel.org Subject: Loopback TCP timer bug? Date: Fri, 11 May 2001 13:15:58 -0600 X-Mailer: KMail [version 1.2] MIME-Version: 1.0 Message-Id: <01051113155804.17685@dragon.linuxcan.com> Content-Transfer-Encoding: 7BIT Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org I've got a problem where a client and server stop talking to each other after around 32 minutes. The server is sending a packet to the client every minute with 4 bytes but the client is in a GUI loop and isn't receiving them. They should just build up in the Recv-Q for the client but after 32 minutes they stop going to the client and instead they stay in the Send-Q of the server. A timer is also started on the server socket so that after 15 times (tcp_retries2) of attempting to send, it returns back ETIMEDOUT and the server exits. A tcpdump shows that the server is sending the 4 byte packet every minute but that after 32 minutes, the client stops acking them. Why would it do that? This is all using localhost and the Recv-Q of the client only ends up with 124 bytes of data in it so I don't think its buffer is filling. The problem doesn't seem to exist on the 2.4.x kernels and only occurs on systems using the 2.2.x kernels. Was there a fix along the way for this? Here is the last bit of the tcpdump: 18:06:11.135201 localhost.localdomain.gds_db > localhost.localdomain.3139: P 16:20(4) ack 1 win 31072 (DF) (ttl 64, id 41071) 18:06:11.135201 localhost.localdomain.gds_db > localhost.localdomain.3139: P 16:20(4) ack 1 win 31072 (DF) (ttl 64, id 41071) 18:06:11.154090 localhost.localdomain.3139 > localhost.localdomain.gds_db: . ack 20 win 30952 (DF) (ttl 64, id 41072) 18:06:11.154090 localhost.localdomain.3139 > localhost.localdomain.gds_db: . ack 20 win 30952 (DF) (ttl 64, id 41072) 18:07:11.131571 localhost.localdomain.gds_db > localhost.localdomain.3139: P 20:24(4) ack 1 win 31072 (DF) (ttl 64, id 41073) 18:07:11.131571 localhost.localdomain.gds_db > localhost.localdomain.3139: P 20:24(4) ack 1 win 31072 (DF) (ttl 64, id 41073) 18:07:11.151759 localhost.localdomain.3139 > localhost.localdomain.gds_db: . ack 24 win 30948 (DF) (ttl 64, id 41074) 18:07:11.151759 localhost.localdomain.3139 > localhost.localdomain.gds_db: . ack 24 win 30948 (DF) (ttl 64, id 41074) 18:08:11.128095 localhost.localdomain.gds_db > localhost.localdomain.3139: P 24:28(4) ack 1 win 31072 (DF) (ttl 64, id 41075) 18:08:11.128095 localhost.localdomain.gds_db > localhost.localdomain.3139: P 24:28(4) ack 1 win 31072 (DF) (ttl 64, id 41075) 18:08:11.331289 localhost.localdomain.gds_db > localhost.localdomain.3139: P 24:28(4) ack 1 win 31072 (DF) (ttl 64, id 41076) 18:08:11.331289 localhost.localdomain.gds_db > localhost.localdomain.3139: P 24:28(4) ack 1 win 31072 (DF) (ttl 64, id 41076) 18:08:11.725170 localhost.localdomain.gds_db > localhost.localdomain.3139: P 24:28(4) ack 1 win 31072 (DF) (ttl 64, id 41077) 18:08:11.725170 localhost.localdomain.gds_db > localhost.localdomain.3139: P 24:28(4) ack 1 win 31072 (DF) (ttl 64, id 41077) 18:08:12.529711 localhost.localdomain.gds_db > localhost.localdomain.3139: P 24:28(4) ack 1 win 31072 (DF) (ttl 64, id 41078) 18:08:12.529711 localhost.localdomain.gds_db > localhost.localdomain.3139: P 24:28(4) ack 1 win 31072 (DF) (ttl 64, id 41078) 18:08:14.133679 localhost.localdomain.gds_db > localhost.localdomain.3139: P 24:28(4) ack 1 win 31072 (DF) (ttl 64, id 41079) 18:08:14.133679 localhost.localdomain.gds_db > localhost.localdomain.3139: P 24:28(4) ack 1 win 31072 (DF) (ttl 64, id 41079) 18:08:17.326826 localhost.localdomain.gds_db > localhost.localdomain.3139: P 24:28(4) ack 1 win 31072 (DF) (ttl 64, id 41080) 18:08:17.326826 localhost.localdomain.gds_db > localhost.localdomain.3139: P 24:28(4) ack 1 win 31072 (DF) (ttl 64, id 41080) 18:08:23.726980 localhost.localdomain.gds_db > localhost.localdomain.3139: P 24:28(4) ack 1 win 31072 (DF) (ttl 64, id 41081) 18:08:23.726980 localhost.localdomain.gds_db > localhost.localdomain.3139: P 24:28(4) ack 1 win 31072 (DF) (ttl 64, id 41081) 18:08:36.527097 localhost.localdomain.gds_db > localhost.localdomain.3139: P 24:28(4) ack 1 win 31072 (DF) (ttl 64, id 41082) 18:08:36.527097 localhost.localdomain.gds_db > localhost.localdomain.3139: P 24:28(4) ack 1 win 31072 (DF) (ttl 64, id 41082) -- Brad Pepers brad@linuxcanada.com