From: Vladimir Davydov <vdavydov.dev@gmail.com>
To: Konstantin Osipov <kostja@tarantool.org>
Cc: tarantool-patches@freelists.org
Subject: Re: [PATCH 8/8] vinyl: keep track of thread pool idle ratio
Date: Thu, 6 Sep 2018 11:18:51 +0300 [thread overview]
Message-ID: <20180906081851.tlkeedihyfe5qoff@esperanza> (raw)
In-Reply-To: <20180906074937.GH8205@chai>
On Thu, Sep 06, 2018 at 10:49:37AM +0300, Konstantin Osipov wrote:
> * Vladimir Davydov <vdavydov.dev@gmail.com> [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?
It is measured for entire pool - note that I divide the result by
worker_count. E.g. if there were two workers and one of them were
busy all the time between two last dumps while another were idle,
idle_ratio would be 0.5.
next prev parent reply other threads:[~2018-09-06 8:18 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-02 20:18 [PATCH 0/7] vinyl: improve stats for throttling Vladimir Davydov
2018-09-02 20:18 ` [PATCH 1/7] vinyl: fix accounting of secondary index cache statements Vladimir Davydov
2018-09-02 22:26 ` [tarantool-patches] " Konstantin Osipov
2018-09-02 20:18 ` [PATCH 2/7] vinyl: add global memory stats Vladimir Davydov
2018-09-02 22:27 ` [tarantool-patches] " Konstantin Osipov
2018-09-02 22:27 ` Konstantin Osipov
2018-09-03 8:10 ` Vladimir Davydov
2018-09-02 20:18 ` [PATCH 3/7] vinyl: add global disk stats Vladimir Davydov
2018-09-02 22:30 ` [tarantool-patches] " Konstantin Osipov
2018-09-02 20:18 ` [PATCH 4/7] vinyl: fix force compaction logic Vladimir Davydov
2018-09-02 20:18 ` [PATCH 5/7] vinyl: update compact priority usual way on range split/coalesce Vladimir Davydov
2018-09-02 20:18 ` [PATCH 6/7] vinyl: keep track of compaction queue length and debt Vladimir Davydov
2018-09-02 20:19 ` [PATCH 7/7] vinyl: keep track of disk idle time Vladimir Davydov
2018-09-04 11:54 ` Vladimir Davydov
2018-09-04 17:23 ` Vladimir Davydov
2018-09-04 17:23 ` [PATCH 1/8] vinyl: add helper to check whether dump is in progress Vladimir Davydov
2018-09-06 7:33 ` Konstantin Osipov
2018-09-04 17:23 ` [PATCH 2/8] vinyl: don't use mempool for allocating background tasks Vladimir Davydov
2018-09-06 7:33 ` Konstantin Osipov
2018-09-04 17:23 ` [PATCH 3/8] vinyl: factor out worker pool from scheduler struct Vladimir Davydov
2018-09-06 7:34 ` Konstantin Osipov
2018-09-04 17:23 ` [PATCH 4/8] vinyl: move worker allocation closer to task creation Vladimir Davydov
2018-09-06 7:35 ` Konstantin Osipov
2018-09-04 17:23 ` [PATCH 5/8] vinyl: use separate thread pools for dump and compaction tasks Vladimir Davydov
2018-09-06 7:37 ` Konstantin Osipov
2018-09-06 9:48 ` Vladimir Davydov
2018-09-06 10:32 ` Konstantin Osipov
2018-09-04 17:23 ` [PATCH 6/8] vinyl: zap vy_worker_pool::idle_worker_count Vladimir Davydov
2018-09-06 7:38 ` Konstantin Osipov
2018-09-04 17:23 ` [PATCH 7/8] vinyl: don't start scheduler fiber until local recovery is complete Vladimir Davydov
2018-09-06 7:39 ` Konstantin Osipov
2018-09-04 17:23 ` [PATCH 8/8] vinyl: keep track of thread pool idle ratio Vladimir Davydov
2018-09-06 7:49 ` Konstantin Osipov
2018-09-06 8:18 ` Vladimir Davydov [this message]
2018-09-06 10:26 ` Konstantin Osipov
2018-09-06 10:52 ` Vladimir Davydov
2018-09-06 10:57 ` Konstantin Osipov
2018-09-06 11:59 ` Vladimir Davydov
2018-09-09 11:41 ` [PATCH 0/7] vinyl: improve stats for throttling Vladimir Davydov
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