Re: [HACKERS] Infrastructure changes for recovery

On Mon, 2008-09-08 at 13:34 -0400, Tom Lane wrote:

> ISTM that it would probably be better if there were exactly one InRedo
> flag in shared memory, probably in xlog.c's shared state, with the
> postmaster not being responsible for setting or clearing it; rather
> the startup process should do those things.

Done

> > * bgwriter and stats process starts in consistent recovery mode.
> > bgwriter changes mode when startup process completes.
>
> I'm not sure about the interaction of this. In particular, what about
> recovery restart points before we have reached the safe stop point?
> I don't think we want to give up the capability of having those.
>
> Also, it seems pretty bogus to update the in-memory ControlFile
> checkpoint values before the restart point is actually done. It looks
> to me like what you have done is to try to use those fields as signaling
> for the restart request in addition to their existing purposes, which
> I think is confusing and probably dangerous. I'd rather there were a
> different signaling path and ControlFile maintains its currrent
> definition.

Done

Testing takes a while on this, I probably won't complete it until
Friday. So enclosed patch is for eyeballs only at this stage.

I added in the XLogCtl padding we've discussed before, while I'm there.

--
Simon Riggs www.2ndQuadrant.com
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