Re: BUG #4879: bgwriter fails to fsync the file in recovery mode

On Thu, 2009-06-25 at 11:31 -0400, Tom Lane wrote:
> Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> writes:
> > Heikki Linnakangas wrote:
> >> Hmm, what happens when the startup process performs a write, and
> >> bgwriter is not running? Do the fsync requests queue up in the shmem
> >> queue until the end of recovery when bgwriter is launched? I guess I'll
> >> have to try it out...
>
> > Oh dear, doesn't look good. The startup process has a pendingOpsTable of
> > its own. bgwriter won't fsync() files that the startup process has
> > written itself. That needs to be fixed, or you can lose data when an
> > archive recovery crashes after a restartpoint.
>
> Ouch.  I'm beginning to think that the best thing is to temporarily
> revert the change that made bgwriter active during recovery.

That seems the safest course, to avoid derailing the schedule.

Please define "temporarily". Will it be re-enabled in 8.4.1, assuming we
find an acceptable fix?

> It's
> obviously not been adequately thought through or tested.

Hmmm...

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 Simon Riggs           www.2ndQuadrant.com
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