From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757380Ab3A1OkW (ORCPT ); Mon, 28 Jan 2013 09:40:22 -0500 Received: from moutng.kundenserver.de ([212.227.17.9]:62917 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757274Ab3A1OkT (ORCPT ); Mon, 28 Jan 2013 09:40:19 -0500 Date: Mon, 28 Jan 2013 15:40:06 +0100 From: Leandro Lucarella To: Vijay Subramanian Cc: Nivedita Singhvi , Rick Jones , Eric Dumazet , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: Doubts about listen backlog and tcp_max_syn_backlog Message-ID: <20130128144006.GQ4608@sociomantic.com> References: <50FF0C25.9000300@hp.com> <20130123104736.GK4608@sociomantic.com> <510039C8.7040401@hp.com> <20130124122223.GQ4608@sociomantic.com> <51018110.1070403@hp.com> <20130124192125.GD4608@sociomantic.com> <5102225E.2040506@gmail.com> <20130125100525.GE4608@sociomantic.com> <5105E6F2.2010805@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Paranoid: Just because you're paranoid, don't mean they're not after you. User-Agent: Mutt/1.5.21 (2010-09-15) X-Provags-ID: V02:K0:2gLVhENgiLoCpqABYgdNML1PluzCJpev/A4UKviLz5A gIWJXZaL7qb0jGlpJSWIoaM97GNHq7Nxc3F5Rz85ckc4ao1eDU ZmfthFhDP77S+qYsdU693DMoEIjYYmlvOFj5hpUtvHrlp42jOt JqIN7UGwJJ+h4D82Au5sOfstnq1kqBkoYu6fMhpkQWoLSw74AU Q67KCWV/eAu0uUgDve3ff9uf8C/0B4LDPvCviOpw2kFWq9kRQ+ lPItP3B0kUxOFnSS1y3vnwIlp9f2TBSyDBnfXAXwvxc3bW/FLl vNEEf1waXlFTAVveBGvASv36z5LUl28aiYnvJs8NtLk72LGidA L3UBV+wGm8bC77QENSCk5ale7YCbn634ACB5eBa+d7zu7myu4B apdKKJfOlcVvQ== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jan 27, 2013 at 09:21:32PM -0800, Vijay Subramanian wrote: > > + { "ListenDrops", N_("%u SYNs to LISTEN sockets dropped"), opt_number }, > > > > (see the file debian/patches/CVS-20081003-statistics.c_sync.patch > > in the net-tools src) > > > > i.e., the netstat pkg is printing the value of the TCPEXT MIB counter > > that's counting TCPExtListenDrops. > > > > Theoretically, that number should be the same as that printed by nstat, > > as they are getting it from the same kernel stats counter. I have not > > looked at nstat code (I actually almost always dump the counters from > > /proc/net/{netstat + snmp} via a simple prettyprint script (will send > > you that offline). > > nstat pretty much does what you describe which is to parse the > /proc/net files(s) and print the contents. This is one advantage of > nstat over netstat. When you add a new MIB, you do not need to update > nstat. Well, something seems to be broken in the nstat I have because using the script to parse the start instead I get the the same values as with netstat. [2 minutes later, and after observing the values of nstat changed in the same server] OK, it looks like nstat is showing some transcient values, using nstat -a I get the "absolute values of counters" (as stated in the man page). By default it seems to print the values for the last 60 seconds, so mistery solved. -- Leandro Lucarella sociomantic labs GmbH http://www.sociomantic.com