Re: Re: [COMMITTERS] pgsql: Make standby server continuously retry restoring the next WAL

Hamlin, Garick L <ghamlin@isc.upenn.edu>

From: Garick Hamlin <ghamlin@isc.upenn.edu>

To: Kevin Grittner <Kevin.Grittner@wicourts.gov>

Cc: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>, Aidan Van Dyk <aidan@highrise.ca>, Simon Riggs <simon@2ndQuadrant.com>, Fujii Masao <masao.fujii@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>

Date: 2010-02-11T19:45:13Z

Lists: pgsql-hackers

On Thu, Feb 11, 2010 at 01:22:44PM -0500, Kevin Grittner wrote:
> Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> wrote:
>  
> > I think 'rsync' has the same problem.
>  
> There is a switch you can use to create the problem under rsync, but
> by default rsync copies to a temporary file name and moves the
> completed file to the target name.
>  
> -Kevin

I don't use PITR, So I don't know any of the well understood facts about 
PITR with postgres, but my understanding with rsync is ...

It doesn't fsync data before rename, its something like: open / write / 
close / rename, which could lead to zero length files on some filesystems.  
(are there other anomalies to worry about here?)

Would that be a concern?  

Garick

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