From:
Simon Riggs <simon(at)2ndQuadrant(dot)com>
To:
Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
Cc:
Fujii Masao <masao(dot)fujii(at)gmail(dot)com>, Robert Haas <robertmhaas(at)gmail(dot)com>,
David Fetter <david(at)fetter(dot)org>, Bruce Momjian <bruce(at)momjian(dot)us>,
fazool mein <fazoolmein(at)gmail(dot)com>, pgsql-hackers(at)postgresql(dot)org
Subject:
Re: Synchronous replication - patch status inquiry
Date:
2010-09-03 07:45:30
Message-ID:
1283499930.1834.2711.camel@ebony (view raw or flat )
Thread:
2010-08-31 21:34:05 from fazool mein <fazoolmein(at)gmail(dot)com>
2010-08-31 21:44:15 from Bruce Momjian <bruce(at)momjian(dot)us>
2010-08-31 22:24:14 from David Fetter <david(at)fetter(dot)org>
2010-09-01 00:34:31 from Robert Haas <robertmhaas(at)gmail(dot)com>
2010-09-01 00:45:47 from David Fetter <david(at)fetter(dot)org>
2010-09-01 01:02:51 from Robert Haas <robertmhaas(at)gmail(dot)com>
2010-09-01 05:33:07 from Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
2010-09-01 07:53:38 from Fujii Masao <masao(dot)fujii(at)gmail(dot)com>
2010-09-01 10:23:56 from Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
2010-09-01 16:03:55 from Robert Haas <robertmhaas(at)gmail(dot)com>
2010-09-01 20:43:01 from Simon Riggs <simon(at)2ndQuadrant(dot)com>
2010-09-02 10:24:05 from Fujii Masao <masao(dot)fujii(at)gmail(dot)com>
2010-09-02 12:03:38 from Simon Riggs <simon(at)2ndQuadrant(dot)com>
2010-09-02 12:15:17 from Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
2010-09-02 12:44:27 from Simon Riggs <simon(at)2ndQuadrant(dot)com>
2010-09-02 12:59:28 from Robert Haas <robertmhaas(at)gmail(dot)com>
2010-09-02 13:51:18 from Dimitri Fontaine <dfontaine(at)hi-media(dot)com>
2010-09-02 14:06:29 from Simon Riggs <simon(at)2ndQuadrant(dot)com>
2010-09-02 14:17:29 from Robert Haas <robertmhaas(at)gmail(dot)com>
2010-09-02 14:32:33 from Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
2010-09-03 03:50:50 from Fujii Masao <masao(dot)fujii(at)gmail(dot)com>
2010-09-03 06:36:27 from Simon Riggs <simon(at)2ndQuadrant(dot)com>
2010-09-03 06:55:37 from Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
2010-09-03 07:45:30 from Simon Riggs <simon(at)2ndQuadrant(dot)com>
2010-09-03 09:33:43 from Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
2010-09-03 10:20:09 from Simon Riggs <simon(at)2ndQuadrant(dot)com>
2010-09-03 10:31:07 from Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
2010-09-06 13:03:44 from Dimitri Fontaine <dfontaine(at)hi-media(dot)com>
2010-09-06 13:14:57 from Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
2010-09-06 14:14:08 from Simon Riggs <simon(at)2ndQuadrant(dot)com>
2010-09-06 23:48:17 from Robert Haas <robertmhaas(at)gmail(dot)com>
2010-09-07 06:27:52 from Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
2010-09-07 09:47:54 from Simon Riggs <simon(at)2ndQuadrant(dot)com>
2010-09-07 10:11:38 from Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
2010-09-07 10:24:37 from Simon Riggs <simon(at)2ndQuadrant(dot)com>
2010-09-07 14:47:27 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2010-09-07 15:23:43 from Simon Riggs <simon(at)2ndQuadrant(dot)com>
2010-09-07 15:41:52 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2010-09-07 15:54:16 from Robert Haas <robertmhaas(at)gmail(dot)com>
2010-09-07 15:59:31 from Simon Riggs <simon(at)2ndQuadrant(dot)com>
2010-09-07 16:07:54 from Robert Haas <robertmhaas(at)gmail(dot)com>
2010-09-07 18:15:43 from Simon Riggs <simon(at)2ndQuadrant(dot)com>
2010-09-07 18:27:36 from Robert Haas <robertmhaas(at)gmail(dot)com>
2010-09-07 23:00:48 from Bruce Momjian <bruce(at)momjian(dot)us>
2010-09-03 07:08:12 from Fujii Masao <masao(dot)fujii(at)gmail(dot)com>
2010-09-03 06:42:51 from Fujii Masao <masao(dot)fujii(at)gmail(dot)com>
2010-09-10 02:52:20 from Fujii Masao <masao(dot)fujii(at)gmail(dot)com>
2010-09-10 02:57:30 from Fujii Masao <masao(dot)fujii(at)gmail(dot)com>
2010-09-14 21:38:17 from David Fetter <david(at)fetter(dot)org>
2010-09-15 09:58:54 from Fujii Masao <masao(dot)fujii(at)gmail(dot)com>
2010-09-15 12:39:33 from Fujii Masao <masao(dot)fujii(at)gmail(dot)com>
2010-09-15 23:12:46 from "Erik Rijkers" <er(at)xs4all(dot)nl>
2010-09-15 23:58:21 from "Erik Rijkers" <er(at)xs4all(dot)nl>
2010-09-02 17:17:39 from Joshua Tolley <eggyknap(at)gmail(dot)com>
2010-09-01 11:43:25 from Simon Riggs <simon(at)2ndQuadrant(dot)com>
2010-09-01 01:06:18 from Fujii Masao <masao(dot)fujii(at)gmail(dot)com>
2010-09-01 02:14:33 from fazool mein <fazoolmein(at)gmail(dot)com>
2010-09-01 00:35:47 from Robert Haas <robertmhaas(at)gmail(dot)com>
Lists:
pgsql-hackers
On Fri, 2010-09-03 at 09:55 +0300, Heikki Linnakangas wrote:
> On 03/09/10 09:36, Simon Riggs wrote:
> > On Fri, 2010-09-03 at 12:50 +0900, Fujii Masao wrote:
> >> That design would affect what the standby should reply. If we choose
> >> async/recv/fsync/replay on a per-transaction basis, the standby
> >> should send multiple LSNs and the master needs to decide when
> >> replication has been completed. OTOH, if we choose just sync/async,
> >> the standby has only to send one LSN.
> >>
> >> The former seems to be more useful, but triples the number of ACK
> >> from the standby. I'm not sure whether its overhead is ignorable,
> >> especially when the distance between the master and the standby is
> >> very long.
> >
> > No, it doesn't. There is no requirement for additional messages.
>
> Please explain how you do it then. When a commit record is sent to the
> standby, it needs to acknowledge it 1) when it has received it, 2) when
> it fsyncs it to disk and c) when it's replayed. I don't see how you can
> get around that.
>
> Perhaps you can save a bit by combining multiple messages together, like
> in Nagle's algorithm, but then you introduce extra delays which is
> exactly what you don't want.
>From my perspective, you seem to be struggling to find reasons why this
should not happen, rather than seeing the alternatives that would
obviously present themselves if your attitude was a positive one. We
won't make any progress with this style of discussion.
--
Simon Riggs www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Training and Services
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Next :From: Pavel StehuleDate: 2010-09-03 08:16:12Subject : Re: thousand unrelated data files in pg_default tablespacePrevious :From : Fujii MasaoDate : 2010-09-03 07:08:12Subject : Re: Synchronous replication - patch status inquiry
