From: Vladimir Davydov <vdavydov.dev@gmail.com>
To: Konstantin Osipov <kostja@tarantool.org>
Cc: tarantool-patches@freelists.org
Subject: Re: [tarantool-patches] Re: [PATCH 7/9] vinyl: randomize range compaction to avoid IO load spikes
Date: Wed, 6 Feb 2019 17:00:48 +0300 [thread overview]
Message-ID: <20190206140048.in7tcapprvfkt2xo@esperanza> (raw)
In-Reply-To: <20190206134341.GB24382@chai>
On Wed, Feb 06, 2019 at 04:43:41PM +0300, Konstantin Osipov wrote:
> * Vladimir Davydov <vdavydov.dev@gmail.com> [19/02/06 14:53]:
> > We know which run is last. Provided the workload is stable, i.e. have
> > stopped growing its dataset, it will be roughly the same. Besides, the
> > last level run size changes only on major compaction, which is
> > infrequent. After a major compaction, it's OK to use a different first
> > level size - the point is in order not to break LSM algorithm, we have
> > to maintain stable level sizing between major compactions.
>
> The problem is that you can't use the last level as-is. You need a
> divider, e.g. dumps_per_compaction, which is meaningless until the
> first major compaction has happened.
Why? Level sizing isn't tight. Sizes of runs at level L range from
X*run_size_ratio^L to X*run_size_ratio^(L+1). We can choose X as we
please without breaking LSM algorithm assumptions, can't we?
next prev parent reply other threads:[~2019-02-06 14:00 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-20 21:16 [PATCH 0/9] vinyl: compaction randomization and throttling Vladimir Davydov
2019-01-20 21:17 ` [PATCH 1/9] vinyl: update lsm->range_heap in one go on dump completion Vladimir Davydov
2019-01-24 16:55 ` Vladimir Davydov
2019-02-05 16:37 ` [tarantool-patches] " Konstantin Osipov
2019-01-20 21:17 ` [PATCH 2/9] vinyl: ignore unknown .run, .index and .vylog keys Vladimir Davydov
2019-01-24 16:56 ` Vladimir Davydov
2019-01-20 21:17 ` [PATCH 3/9] vinyl: use uncompressed run size for range split/coalesce/compaction Vladimir Davydov
2019-01-21 9:42 ` Vladimir Davydov
2019-02-05 16:49 ` [tarantool-patches] " Konstantin Osipov
2019-02-06 8:55 ` Vladimir Davydov
2019-02-06 10:46 ` Konstantin Osipov
2019-02-06 10:55 ` Vladimir Davydov
2019-02-05 16:43 ` Konstantin Osipov
2019-02-06 16:48 ` Vladimir Davydov
2019-01-20 21:17 ` [PATCH 4/9] vinyl: rename lsm->range_heap to max_compaction_priority Vladimir Davydov
2019-01-20 21:17 ` [PATCH 5/9] vinyl: keep track of dumps per compaction for each LSM tree Vladimir Davydov
2019-02-05 16:58 ` [tarantool-patches] " Konstantin Osipov
2019-02-06 9:20 ` Vladimir Davydov
2019-02-06 16:54 ` Vladimir Davydov
2019-01-20 21:17 ` [PATCH 6/9] vinyl: set range size automatically Vladimir Davydov
2019-01-22 9:17 ` Vladimir Davydov
2019-02-05 17:09 ` [tarantool-patches] " Konstantin Osipov
2019-02-06 9:23 ` Vladimir Davydov
2019-02-06 17:04 ` Vladimir Davydov
2019-01-20 21:17 ` [PATCH 7/9] vinyl: randomize range compaction to avoid IO load spikes Vladimir Davydov
2019-01-22 12:54 ` Vladimir Davydov
2019-02-05 17:39 ` [tarantool-patches] " Konstantin Osipov
2019-02-06 8:53 ` Vladimir Davydov
2019-02-06 10:44 ` Konstantin Osipov
2019-02-06 10:52 ` Vladimir Davydov
2019-02-06 11:06 ` Konstantin Osipov
2019-02-06 11:49 ` Vladimir Davydov
2019-02-06 13:43 ` Konstantin Osipov
2019-02-06 14:00 ` Vladimir Davydov [this message]
2019-02-05 17:14 ` Konstantin Osipov
2019-01-20 21:17 ` [PATCH 8/9] vinyl: introduce quota consumer types Vladimir Davydov
2019-01-20 21:17 ` [PATCH 9/9] vinyl: throttle tx to ensure compaction keeps up with dumps Vladimir Davydov
2019-01-21 14:14 ` Vladimir Davydov
2019-01-22 9:09 ` Vladimir Davydov
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