From: Andres Freund <andres@anarazel.de>
To: pgsql-hackers@postgresql.org
Cc: Robert Haas <robertmhaas@gmail.com>
Cc: Alvaro Herrera <alvherre@commandprompt.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Greg Smith <greg@2ndquadrant.com>
Cc: Greg Stark <gsstark@mit.edu>
Cc: pgsql-performance@postgresql.org, Michael Clemmons <glassresistor@gmail.com>
Cc: Hannu Krosing <hannu@2ndquadrant.com>
Cc: Scott Marlowe <scott.marlowe@gmail.com>
Subject: Re: [HACKERS] Re: Faster CREATE DATABASE by delaying fsync (was 8.4.1 ubuntu karmic slow createdb)
Date: Thu, 11 Feb 2010 03:27:30 +0100
Message-ID: <201002110327.35810.andres@anarazel.de> (raw)
In-Reply-To: <603c8f071002072053w16897addtd52fcc4cf880df53@mail.gmail.com>
References: <4427a97a0912101235x3ade510blcc00d5ce9883c6b6@mail.gmail.com>
<20100208030901.GA7407@alvh.no-ip.org>
<603c8f071002072053w16897addtd52fcc4cf880df53@mail.gmail.com>
On Monday 08 February 2010 05:53:23 Robert Haas wrote:
> On Sun, Feb 7, 2010 at 10:09 PM, Alvaro Herrera
>
> <alvherre@commandprompt.com> wrote:
> > Andres Freund escribió:
> >> I personally think the fsync on the directory should be added to the
> >> stable branches - other opinions?
> >> If wanted I can prepare patches for that.
> >
> > Yeah, it seems there are two patches here -- one is the addition of
> > fsync_fname() and the other is the fsync_prepare stuff.
>
> Andres, you want to take a crack at splitting this up?
I hope I didnt duplicate Gregs work, but I didnt hear back from him, so...
Everything <8.1 is hopeless because cp is used there... I didnt see it worth
to replace that. The patch applies cleanly for 8.1 to 8.4 and survives the
regression tests
Given pg's heavy commit model I didnt see a point to split the patch for 9.0
as well...
Andres
Attachments:directory-fsync-8.1-to-8.4.patch (text/x-patch, 1.1K) downloaddiff --git a/src/port/copydir.c b/src/port/copydir.cindex 72fbf36..b057ffa 100644
*** a/src/port/copydir.c
--- b/src/port/copydir.c
*************** copydir(char *fromdir, char *todir, bool
*** 50,55 ****
--- 50,56 ----
{
DIR *xldir;
struct dirent *xlde;
+ int dirfd;
char fromfile[MAXPGPATH];
char tofile[MAXPGPATH];
*************** copydir(char *fromdir, char *todir, bool
*** 91,96 ****
--- 92,116 ----
}
FreeDir(xldir);
+ + /*+ * fsync the directory to make sure data has reached the+ * disk. While needed by most filesystems, the window got bigger+ * with newer ones like ext4.+ */+ dirfd = BasicOpenFile(todir,+ O_RDONLY | PG_BINARY,+ S_IRUSR | S_IWUSR);+ if(dirfd == -1)+ ereport(ERROR,+ (errcode_for_file_access(),+ errmsg("could not open directory for fsync \"%s\": %m", todir)));+ + if(pg_fsync(dirfd) == -1)+ ereport(ERROR,+ (errcode_for_file_access(),+ errmsg("could not fsync directory \"%s\": %m", todir)));+ close(dirfd);
}
/*
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To: pgsql-hackers@postgresql.org
Cc: andres@anarazel.de, robertmhaas@gmail.com, alvherre@commandprompt.com, tgl@sss.pgh.pa.us, greg@2ndquadrant.com, gsstark@mit.edu, glassresistor@gmail.com, hannu@2ndquadrant.com, scott.marlowe@gmail.com
Subject: Re: [HACKERS] Re: Faster CREATE DATABASE by delaying fsync (was 8.4.1 ubuntu karmic slow createdb)
In-Reply-To: <201002110327.35810.andres@anarazel.de>
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