From:
Bruce Momjian <bruce(at)momjian(dot)us>
To:
Kevin Grittner <Kevin(dot)Grittner(at)wicourts(dot)gov>
Cc:
Robert Haas <robertmhaas(at)gmail(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>,
Greg Smith <greg(at)2ndquadrant(dot)com>, Josh Berkus <josh(at)agliodbs(dot)com>,
Ron Mayer <rm_pg(at)cheapcomplexdevices(dot)com>,
Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>,
Itagaki Takahiro <itagaki(dot)takahiro(at)gmail(dot)com>, pgsql-hackers(at)postgresql(dot)org
Subject:
Re: Spread checkpoint sync
Date:
2011-02-01 18:32:22
Message-ID:
201102011832.p11IWN519696@momjian.us (view raw or flat )
Thread:
2010-11-14 23:48:24 from Greg Smith <greg(at)2ndquadrant(dot)com>
2010-11-16 02:15:32 from Robert Haas <robertmhaas(at)gmail(dot)com>
2010-11-20 23:21:48 from Jeff Janes <jeff(dot)janes(at)gmail(dot)com>
2010-11-21 01:17:47 from Robert Haas <robertmhaas(at)gmail(dot)com>
2010-11-21 02:11:40 from Jeff Janes <jeff(dot)janes(at)gmail(dot)com>
2010-11-21 16:37:26 from Greg Smith <greg(at)2ndquadrant(dot)com>
2010-11-21 23:07:20 from Josh Berkus <josh(at)agliodbs(dot)com>
2010-11-27 01:51:05 from Ron Mayer <rm_pg(at)cheapcomplexdevices(dot)com>
2010-11-30 20:29:57 from Greg Smith <greg(at)2ndquadrant(dot)com>
2010-11-30 20:58:09 from Josh Berkus <josh(at)agliodbs(dot)com>
2011-01-12 01:27:36 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-15 10:47:24 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-01-15 12:05:57 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-15 14:25:40 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-01-15 14:40:59 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-15 15:31:05 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-01-15 21:28:17 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-15 22:57:02 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-01-16 04:14:34 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-16 07:28:58 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-01-17 16:19:20 from Bruce Momjian <bruce(at)momjian(dot)us>
2011-01-18 01:46:21 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-01-18 10:26:51 from Cédric Villemain <cedric(dot)villemain(dot)debian(at)gmail(dot)com>
2011-01-16 03:35:17 from Marti Raudsepp <marti(at)juffo(dot)org>
2011-01-16 05:11:26 from Simone Aiken <saiken(at)ulfheim(dot)net>
2011-01-16 11:29:37 from Nicolas Barbier <nicolas(dot)barbier(at)gmail(dot)com>
2011-01-16 16:34:31 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2011-01-16 18:47:11 from Simone Aiken <saiken(at)ulfheim(dot)net>
2011-01-18 06:47:50 from Simone Aiken <saiken(at)ulfheim(dot)net>
2011-01-18 13:35:58 from Alvaro Herrera <alvherre(at)commandprompt(dot)com>
2011-01-18 15:46:18 from Simone Aiken <saiken(at)ulfheim(dot)net>
2011-01-18 16:44:26 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-18 17:16:05 from "Simone Aiken" <saiken(at)ulfheim(dot)net>
2011-01-18 21:52:43 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-18 23:49:29 from "Simone Aiken" <saiken(at)quietlyCompetent(dot)com>
2011-01-19 18:25:00 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-19 19:25:59 from Alvaro Herrera <alvherre(at)commandprompt(dot)com>
2011-01-19 19:26:02 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2011-01-19 19:39:29 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-19 20:10:39 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2011-01-19 20:19:24 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-19 22:43:56 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2011-01-20 21:40:09 from "Simone Aiken" <saiken(at)quietlyCompetent(dot)com>
2011-01-21 02:16:43 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-21 15:00:14 from Bruce Momjian <bruce(at)momjian(dot)us>
2011-01-19 21:27:16 from "Simone Aiken" <saiken(at)ulfheim(dot)net>
2011-01-20 14:27:38 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-18 21:36:25 from Bruce Momjian <bruce(at)momjian(dot)us>
2011-01-19 16:19:47 from "Simone Aiken" <saiken(at)quietlyCompetent(dot)com>
2011-01-18 13:39:05 from Alvaro Herrera <alvherre(at)commandprompt(dot)com>
2011-01-18 11:19:15 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-01-15 13:55:21 from Simon Riggs <simon(at)2ndQuadrant(dot)com>
2011-01-15 14:15:49 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-15 20:53:18 from Simon Riggs <simon(at)2ndQuadrant(dot)com>
2011-01-17 23:07:38 from Jim Nasby <jim(at)nasby(dot)net>
2011-01-18 00:27:34 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-18 00:33:07 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-02-03 22:55:10 from Michael Banck <mbanck(at)debian(dot)org>
2011-02-04 18:43:23 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-01-17 00:32:55 from Jeff Janes <jeff(dot)janes(at)gmail(dot)com>
2011-01-17 01:42:13 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-17 03:13:59 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-01-17 03:37:33 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-17 16:40:31 from Jeff Janes <jeff(dot)janes(at)gmail(dot)com>
2011-01-17 18:48:54 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-01-18 19:12:53 from Josh Berkus <josh(at)agliodbs(dot)com>
2011-01-27 17:18:37 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-01-27 17:27:44 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-27 19:33:21 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-01-28 05:53:24 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-01-29 13:13:04 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-31 04:41:36 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-31 08:04:22 from Itagaki Takahiro <itagaki(dot)takahiro(at)gmail(dot)com>
2011-01-31 14:44:58 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-31 14:52:27 from Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
2011-01-31 16:29:56 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2011-01-31 16:43:01 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-31 16:51:13 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2011-01-31 16:55:38 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-31 17:11:24 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2011-01-31 18:44:38 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-31 20:27:25 from Bruce Momjian <bruce(at)momjian(dot)us>
2011-01-31 21:28:01 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2011-02-01 17:44:05 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-02-01 17:58:52 from "Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov>
2011-02-01 18:32:22 from Bruce Momjian <bruce(at)momjian(dot)us>
2011-02-01 18:32:28 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-02-01 18:30:12 from Bruce Momjian <bruce(at)momjian(dot)us>
2011-02-01 18:35:13 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2011-02-01 18:48:42 from Bruce Momjian <bruce(at)momjian(dot)us>
2011-01-31 21:04:13 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-01-31 17:01:48 from Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
2011-01-31 17:04:00 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-01-31 21:33:18 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-02-01 15:49:03 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-02-01 18:30:53 from Bruce Momjian <bruce(at)momjian(dot)us>
2011-02-04 19:08:07 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-02-04 19:39:06 from Robert Haas <robertmhaas(at)gmail(dot)com>
2011-02-07 07:07:41 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-02-07 15:22:15 from Cédric Villemain <cedric(dot)villemain(dot)debian(at)gmail(dot)com>
2011-02-07 15:44:05 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-02-07 18:38:34 from "Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov>
2011-02-07 22:06:46 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-02-11 03:30:44 from Greg Smith <greg(at)2ndquadrant(dot)com>
2011-02-11 04:01:33 from Robert Haas <robertmhaas(at)gmail(dot)com>
2010-11-21 21:54:00 from Greg Smith <greg(at)2ndquadrant(dot)com>
2010-11-21 22:19:30 from Martijn van Oosterhout <kleptog(at)svana(dot)org>
2010-11-21 22:45:50 from Andres Freund <andres(at)anarazel(dot)de>
2010-11-24 02:23:49 from Cédric Villemain <cedric(dot)villemain(dot)debian(at)gmail(dot)com>
2010-11-22 00:05:06 from Robert Haas <robertmhaas(at)gmail(dot)com>
2010-11-30 22:56:46 from Jeff Janes <jeff(dot)janes(at)gmail(dot)com>
2010-12-01 04:25:47 from Greg Smith <greg(at)2ndquadrant(dot)com>
2010-12-01 08:50:14 from Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
2010-12-01 21:30:07 from Greg Smith <greg(at)2ndquadrant(dot)com>
2010-12-02 06:11:21 from Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
2010-12-05 21:53:41 from Greg Smith <greg(at)2ndquadrant(dot)com>
2010-12-05 22:32:28 from Rob Wultsch <wultsch(at)gmail(dot)com>
2010-12-05 23:02:48 from Greg Smith <greg(at)2ndquadrant(dot)com>
2010-12-07 02:26:28 from Alvaro Herrera <alvherre(at)commandprompt(dot)com>
2010-12-07 15:27:28 from Greg Smith <greg(at)2ndquadrant(dot)com>
2010-12-08 15:22:59 from Simon Riggs <simon(at)2ndQuadrant(dot)com>
2010-12-02 19:24:13 from Greg Stark <gsstark(at)mit(dot)edu>
2010-12-02 19:48:54 from Josh Berkus <josh(at)agliodbs(dot)com>
2010-12-03 00:12:16 from Robert Haas <robertmhaas(at)gmail(dot)com>
2010-12-05 05:56:51 from Greg Smith <greg(at)2ndquadrant(dot)com>
Lists:
pgsql-hackers
Kevin Grittner wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>
> > I also think Bruce's idea of calling fsync() on each relation just
> > *before* we start writing the pages from that relation might have
> > some merit.
>
> What bothers me about that is that you may have a lot of the same
> dirty pages in the OS cache as the PostgreSQL cache, and you've just
> ensured that the OS will write those *twice*. I'm pretty sure that
> the reason the aggressive background writer settings we use have not
> caused any noticeable increase in OS disk writes is that many
> PostgreSQL writes of the same buffer keep an OS buffer page from
> becoming stale enough to get flushed until PostgreSQL writes to it
> taper off. Calling fsync() right before doing "one last push" of
> the data could be really pessimal for some workloads.
OK, maybe my idea needs to be adjusted and we should trigger an early
fsync if non-fsync writes are coming in for blocks _other_ than the ones
we already wrote for that checkpoint.
--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ It's impossible for everything to be true. +
In response to
pgsql-hackers by date
Next :From: Robert HaasDate: 2011-02-01 18:32:28Subject : Re: Spread checkpoint syncPrevious :From : Bruce MomjianDate : 2011-02-01 18:30:53Subject : Re: Spread checkpoint sync
