From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Thu, 23 Aug 2018 23:54:43 +0300 From: Konstantin Osipov Subject: Re: [PATCH 18/18] vinyl: throttle tx rate if dump does not catch up Message-ID: <20180823205443.GF24711@chai> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: To: Vladimir Davydov Cc: tarantool-patches@freelists.org List-ID: * Vladimir Davydov [18/08/16 23:03]: > If the rate at which transactions are ready to write to the database is > greater than the dump bandwidth, memory will get depleted before the > last dump is complete and all newer transactions will have to wait until > the dump has been completed, which may take seconds or even minutes: Why are you limiting the rate only during a dump? What about compaction throughtput? Write amplification from compaction is 10x+ times higher than from dump, compaction is actually the main consumer of disk bandwidth. Shouldn't you throttle writes when write bandwidth is higher than write amplification/disk bandwidth? -- Konstantin Osipov, Moscow, Russia, +7 903 626 22 32 http://tarantool.io - www.twitter.com/kostja_osipov