Re: warning message in standby
Robert Haas <robertmhaas@gmail.com>
From: Robert Haas <robertmhaas@gmail.com>
To: Kevin Grittner <Kevin.Grittner@wicourts.gov>
Cc: Simon Riggs <simon@2ndquadrant.com>, Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>, Fujii Masao <masao.fujii@gmail.com>, Magnus Hagander <magnus@hagander.net>, Bruce Momjian <bruce@momjian.us>, PostgreSQL-development <pgsql-hackers@postgresql.org>, Tom Lane <tgl@sss.pgh.pa.us>
Date: 2010-07-02T21:47:20Z
Lists: pgsql-hackers
On Tue, Jun 29, 2010 at 10:58 AM, Kevin Grittner <Kevin.Grittner@wicourts.gov> wrote: > Robert Haas <robertmhaas@gmail.com> wrote: > >>> If someone is sloppy about how they copy the WAL files around, >>> they could temporarily have a truncated file. >> >> Can you explain the scenario you're concerned about in more >> detail? > > If someone uses cp or scp to copy a WAL file from the pg_xlog > directory to an archive directory, there will be a window of time > where the file exists and is not complete. If you wait "a while" > (that being a duration which could be highly variable, depending on > the specifics of the environment and copy techniques used), the > missing part of the file will materialize. Drat. It looks like we even recommend that configuration in the docs. Well, I don't know what to do about this, then, but I predict somebody's going to get bitten by it... hard. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise Postgres Company