From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH net-next 3/3] tipc: reduce transmission rate of reset messages when link is down Date: Tue, 5 Apr 2016 23:07:22 +0300 Message-ID: <57041AFA.5090702@cogentembedded.com> References: <1459873255-32354-1-git-send-email-jon.maloy@ericsson.com> <1459873255-32354-4-git-send-email-jon.maloy@ericsson.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, Paul Gortmaker , parthasarathy.bhuvaragan@ericsson.com, richard.alpe@ericsson.com, ying.xue@windriver.com, maloy@donjonn.com, tipc-discussion@lists.sourceforge.net To: Jon Maloy , davem@davemloft.net Return-path: Received: from mail-lf0-f50.google.com ([209.85.215.50]:34335 "EHLO mail-lf0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752167AbcDEUH1 (ORCPT ); Tue, 5 Apr 2016 16:07:27 -0400 Received: by mail-lf0-f50.google.com with SMTP id j11so18633520lfb.1 for ; Tue, 05 Apr 2016 13:07:26 -0700 (PDT) In-Reply-To: <1459873255-32354-4-git-send-email-jon.maloy@ericsson.com> Sender: netdev-owner@vger.kernel.org List-ID: Hello. On 04/05/2016 07:20 PM, Jon Maloy wrote: > When a link is down, it will continuously try to re-establish contact > with the peer by sending out a RESET or and ACTIVATE message at each And/or? > timeout interval. The default value for this interval is currently > 375 ms. This is wasteful, and may become a problem in very large > clusters with dozens or hundereds of nodes being down simultaneously. Hundreds. > We now introduce a simple backoff algorithm for these cases. The > first five messages are sent at default rate; thereafter a message > is sent only each 16't timer interval. 16th? > This will cover the vast majority of link recyling cases, since the Recycling. > endpoint starting last will transmit at the higher speed, and the link > should normally be established well be before the rate needs to be > reduced. > > The only case where we will see a degradation of link re-establishment > is when the endpoins remain intact, and a glitch in the transmission Endpoints. > media is causing the link reset. We will then experience a worst-case > re-establishing time of 6 seconds, something we deem acceptable. > > Acked-by: Ying Xue > Signed-off-by: Jon Maloy [...] MBR, Sergei