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 4163C265AC for ; Mon, 19 Aug 2019 16:57:23 -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 C5EI-fX0lA_6 for ; Mon, 19 Aug 2019 16:57:23 -0400 (EDT) Received: from smtp47.i.mail.ru (smtp47.i.mail.ru [94.100.177.107]) (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 00E23247C2 for ; Mon, 19 Aug 2019 16:57:22 -0400 (EDT) Received: by smtp47.i.mail.ru with esmtpa (envelope-from ) id 1hzoiP-00085o-81 for tarantool-patches@freelists.org; Mon, 19 Aug 2019 23:57:21 +0300 Date: Mon, 19 Aug 2019 23:57:21 +0300 From: Konstantin Osipov Subject: [tarantool-patches] Re: [PATCH v2 7/7] relay: join new replicas off read view Message-ID: <20190819205721.GH21602@atlas> References: <9ed5cd28b89751e0f4edd8f8c9a57d66ba2bd5f8.1566233187.git.vdavydov.dev@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9ed5cd28b89751e0f4edd8f8c9a57d66ba2bd5f8.1566233187.git.vdavydov.dev@gmail.com> 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: tarantool-patches@freelists.org * Vladimir Davydov [19/08/19 19:57]: > Historically, we join a new replica off the last checkpoint. As a > result, we must always keep the last memtx snapshot and all vinyl data > files corresponding to it. Actually, there's no need to use the last > checkpoint for joining a replica. Instead we can use the current read > view as both memtx and vinyl support it. This should speed up the > process of joining a new replica, because we don't need to replay all > xlogs written after the last checkpoint, only those that are accumulated > while we are relaying the current read view. This should also allow us > to avoid creating a snapshot file on bootstrap, because the only reason > why we need it is allowing joining replicas. Besides, this is a step > towards decoupling the vinyl metadata log from checkpointing in > particular and from xlogs in general. > How does this work given relay_* functions are running in a relay thread? -- Konstantin Osipov, Moscow, Russia