From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hagen Paul Pfeifer Subject: Re: [PATCH 0/2] Tracepoint for tcp retransmission Date: Sun, 18 Dec 2011 01:49:44 +0100 Message-ID: <20111218004944.GB14903@hell> References: <65795E11DBF1E645A09CEC7EAEE94B9CB5AFA64F@USINDEVS02.corp.hds.com> <5f654c7d-f18e-4d70-8830-a3e31b8f5f4a@tahiti.vyatta.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Satoru Moriya , nhorman@tuxdriver.com, davem@davemloft.net, tgraf@infradead.org, Seiji Aguchi , dle-develop@lists.sourceforge.net, netdev@vger.kernel.org To: Stephen Hemminger Return-path: Received: from alternativer.internetendpunkt.de ([88.198.24.89]:53230 "EHLO geheimer.internetendpunkt.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751058Ab1LRAts (ORCPT ); Sat, 17 Dec 2011 19:49:48 -0500 Content-Disposition: inline In-Reply-To: <5f654c7d-f18e-4d70-8830-a3e31b8f5f4a@tahiti.vyatta.com> Sender: netdev-owner@vger.kernel.org List-ID: > Sometimes network packets are dropped for some reason. In enterprise > systems which require strict RAS functionality, we must know the > reason why it happened and explain it to our customers even if using > TCP. When we investigate the incidents, at first we try to find out > whether the problem is in the server(kernel, application) or else > (router, hub etc). And next we try to find out which layer > (application/middleware/kernel(IP/TCP/UDP/..)etc.) the problem > occurs. For the first question tcpdump may the right tool. For the later systemtap can be used. I mean we now have the possibility to instrument the kernel at runtime, without bloating the source. Anyway: is 63e03724b51 not suitable to gather the required information easily? Hagen