From: Howard Chu <hyc@symas.com>
To: Gregory Farnum <gfarnum@redhat.com>
Cc: Ric Wheeler <rwheeler@redhat.com>,
ceph-devel <ceph-devel@vger.kernel.org>
Subject: Re: newstore direction
Date: Fri, 23 Oct 2015 22:23:30 +0100 [thread overview]
Message-ID: <562AA552.702@symas.com> (raw)
In-Reply-To: <CAJ4mKGZ_Xg4hNrm-zjBCJwe4vV1CbALT+C_Ee7cmcpRf=VMKKA@mail.gmail.com>
Gregory Farnum wrote:
> On Fri, Oct 23, 2015 at 7:59 AM, Howard Chu <hyc@symas.com> wrote:
>> If the stream of writes is large enough, you could omit fsync because
>> everything is being forced out of the cache to disk anyway. In that
>> scenario, the only thing that matters is that the writes get forced out in
>> the order you intended, so that an interruption or crash leaves you in a
>> known (or knowable) state vs unknown.
>
> The RADOS storage semantics actually require that we know it's durable
> on disk as well, unfortunately. But ordered writes would probably let
> us batch up commit points in ways that are a lot friendlier for the
> drives!
Ah, that's too bad. LMDB does fine with only ordering, but never mind.
--
-- Howard Chu
CTO, Symas Corp. http://www.symas.com
Director, Highland Sun http://highlandsun.com/hyc/
Chief Architect, OpenLDAP http://www.openldap.org/project/
next prev parent reply other threads:[~2015-10-23 21:23 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-19 19:49 newstore direction Sage Weil
2015-10-19 20:22 ` Robert LeBlanc
2015-10-19 20:30 ` Somnath Roy
2015-10-19 20:54 ` Sage Weil
2015-10-19 22:21 ` James (Fei) Liu-SSI
2015-10-20 2:24 ` Chen, Xiaoxi
2015-10-20 12:30 ` Sage Weil
2015-10-20 13:19 ` Mark Nelson
2015-10-20 17:04 ` kernel neophyte
2015-10-21 10:06 ` Allen Samuels
2015-10-21 13:35 ` Mark Nelson
2015-10-21 16:10 ` Chen, Xiaoxi
2015-10-22 1:09 ` Allen Samuels
2015-10-20 2:32 ` Varada Kari
2015-10-20 2:40 ` Chen, Xiaoxi
2015-10-20 12:34 ` Sage Weil
2015-10-20 20:18 ` Martin Millnert
2015-10-20 20:32 ` James (Fei) Liu-SSI
2015-10-20 20:39 ` James (Fei) Liu-SSI
2015-10-20 21:20 ` Sage Weil
2015-10-19 21:18 ` Wido den Hollander
2015-10-19 22:40 ` Varada Kari
2015-10-20 0:48 ` John Spray
2015-10-20 20:00 ` Sage Weil
2015-10-20 20:36 ` Gregory Farnum
2015-10-20 21:47 ` Sage Weil
2015-10-20 22:23 ` Ric Wheeler
2015-10-21 13:32 ` Sage Weil
2015-10-21 13:50 ` Ric Wheeler
2015-10-23 6:21 ` Howard Chu
2015-10-23 11:06 ` Ric Wheeler
2015-10-23 11:47 ` Ric Wheeler
2015-10-23 14:59 ` Howard Chu
2015-10-23 16:37 ` Ric Wheeler
2015-10-23 18:59 ` Gregory Farnum
2015-10-23 21:23 ` Howard Chu [this message]
2015-10-20 20:42 ` Matt Benjamin
2015-10-22 12:32 ` Milosz Tanski
2015-10-23 3:16 ` Howard Chu
2015-10-23 13:27 ` Milosz Tanski
2015-10-20 2:08 ` Haomai Wang
2015-10-20 12:25 ` Sage Weil
2015-10-20 7:06 ` Dałek, Piotr
2015-10-20 18:31 ` Ric Wheeler
2015-10-20 19:44 ` Sage Weil
2015-10-20 21:43 ` Ric Wheeler
2015-10-20 19:44 ` Yehuda Sadeh-Weinraub
2015-10-21 8:22 ` Orit Wasserman
2015-10-21 11:18 ` Ric Wheeler
2015-10-21 17:30 ` Sage Weil
2015-10-22 8:31 ` Christoph Hellwig
2015-10-22 12:50 ` Sage Weil
2015-10-22 17:42 ` James (Fei) Liu-SSI
2015-10-22 23:42 ` Samuel Just
2015-10-23 0:10 ` Samuel Just
2015-10-23 1:26 ` Allen Samuels
2015-10-23 2:06 ` Ric Wheeler
2015-10-21 10:06 ` Allen Samuels
2015-10-21 11:24 ` Ric Wheeler
2015-10-21 14:14 ` Mark Nelson
2015-10-21 15:51 ` Ric Wheeler
2015-10-21 19:37 ` Mark Nelson
2015-10-21 21:20 ` Martin Millnert
2015-10-22 2:12 ` Allen Samuels
2015-10-22 8:51 ` Orit Wasserman
2015-10-22 0:53 ` Allen Samuels
2015-10-22 1:16 ` Ric Wheeler
2015-10-22 1:22 ` Allen Samuels
2015-10-23 2:10 ` Ric Wheeler
2015-10-21 13:44 ` Mark Nelson
2015-10-22 1:39 ` Allen Samuels
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