From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Thu, 6 Sep 2018 10:49:37 +0300 From: Konstantin Osipov Subject: Re: [PATCH 8/8] vinyl: keep track of thread pool idle ratio Message-ID: <20180906074937.GH8205@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 [18/09/04 20:59]: > To understand whether the disk is fully utilized or can still handle > more compaction load and make right decisions regarding transaction > throttling, we need a metric that would report how much time worker > threads spent being idle. So this patch adds two new metrics to global > statistics, disk.dump_idle_ratio and compact_idle_ratio, which show how > much time dump threads and compaction threads were idle, respectively. > The metrics are updated using the following formula: > > idle_time > idle_ratio = -------------------------- > dump_period * worker_count I don't understand the formula. There can be many workers. Is idle time measured per worker or per entire pool? If it is measured per entire pool, how is idle time calculated if some workers are busy and some not? -- Konstantin Osipov, Moscow, Russia, +7 903 626 22 32 http://tarantool.io - www.twitter.com/kostja_osipov