From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 6F4EC2442B for ; Thu, 4 Jul 2019 04:26:11 -0400 (EDT) Received: from turing.freelists.org ([127.0.0.1]) by localhost (turing.freelists.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 648mKzR8UsBG for ; Thu, 4 Jul 2019 04:26:11 -0400 (EDT) Received: from smtp39.i.mail.ru (smtp39.i.mail.ru [94.100.177.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTPS id 30EA423066 for ; Thu, 4 Jul 2019 04:26:11 -0400 (EDT) Date: Thu, 4 Jul 2019 11:26:09 +0300 From: Konstantin Osipov Subject: [tarantool-patches] Re: [PATCH 5/5] swim: speed-up empty payloads cluster bootstrap Message-ID: <20190704082609.GK24820@atlas> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: tarantool-patches-bounce@freelists.org Errors-to: tarantool-patches-bounce@freelists.org Reply-To: tarantool-patches@freelists.org List-Help: List-Unsubscribe: List-software: Ecartis version 1.0.0 List-Id: tarantool-patches List-Subscribe: List-Owner: List-post: List-Archive: To: Vladislav Shpilevoy Cc: tarantool-patches@freelists.org * Vladislav Shpilevoy [19/07/04 10:15]: > One another place consuming most of the tests start up time is > useless dissemination of an empty payload, which can be skipped > in fact. > > Consider a cluster of 300 nodes. Each one of them are > interconnected manually, and now a test wants to wait for a > stabilization, when there are no events. On such a cluster it > happens for ~200 round steps till there are no any single event. > > This is not about big packets, or log() TTD. There may be a few > events, may be more, but when a test wants the cluster to be > clean, it needs to wait for all the events being done. > > This patch abuses the fact, that empty payloads can be compared > for free, no any single memcmp. If both new and the old payload > are empty, then nothing to disseminate. > > It could help in a real cluster too, if initially there are no > payloads. lgtm -- Konstantin Osipov, Moscow, Russia