From:
Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To:
Bruce Momjian <bruce(at)momjian(dot)us>
Cc:
Robert Haas <robertmhaas(at)gmail(dot)com>,
Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>,
Itagaki Takahiro <itagaki(dot)takahiro(at)gmail(dot)com>,
Greg Smith <greg(at)2ndquadrant(dot)com>,
Ron Mayer <rm_pg(at)cheapcomplexdevices(dot)com>,
Josh Berkus <josh(at)agliodbs(dot)com>, pgsql-hackers(at)postgresql(dot)org
Subject:
Re: Spread checkpoint sync
Date:
2011-02-01 18:35:13
Message-ID:
29880.1296585313@sss.pgh.pa.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
Bruce Momjian <bruce(at)momjian(dot)us> writes:
> My trivial idea was: let's assume we checkpoint every 10 minutes, and
> it takes 5 minutes for us to write the data to the kernel. If no one
> else is writing to those files, we can safely wait maybe 5 more minutes
> before issuing the fsync. If, however, hundreds of writes are coming in
> for the same files in those final 5 minutes, we should fsync right away.
Huh? I would surely hope we could assume that nobody but Postgres is
writing the database files? Or are you considering that the bgwriter
doesn't know exactly what the backends are doing? That's true, but
I still maintain that we should design the bgwriter's behavior on the
assumption that writes from backends are negligible. Certainly the
backends aren't issuing fsyncs.
regards, tom lane
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