Re: Use pg_rewind when target timeline was switched

Seems, patch is ready to commit. But it needs some documentation.

Alexander Korotkov wrote:
> On Wed, Sep 30, 2015 at 9:46 AM, Michael Paquier <michael(dot)paquier(at)gmail(dot)com
> <mailto:michael(dot)paquier(at)gmail(dot)com>> wrote:
>
> On Sat, Sep 19, 2015 at 8:27 AM, Michael Paquier wrote:
> > On Fri, Sep 18, 2015 at 6:25 PM, Michael Paquier wrote:
> >> The refactoring of getTimelineHistory as you propose looks like a good
> >> idea to me, I tried to remove by myself the difference between source
> >> and target in copy_fetch.c and friends but this gets uglier,
> >> particularly because of datadir_source in copy_file_range. Not worth
> >> it.
> >
> > Forgot that:
> > if (ControlFile_target.state != DB_SHUTDOWNED)
> > pg_fatal("target server must be shut down cleanly\n");
> > We may want to allow a target node shutdowned in recovery as well here.
>
> So, attached is a more polished version of this patch, cleaned up of
> its typos with as well other things. I have noticed for example that
> it would be more useful to add the debug information of a timeline
> file fetched from the source or a target server directly in
> getTimelineHistory. I have as well updated a couple of comments in the
> code regarding the fact that we do not necessarily use a master as a
> target node, and mentioned in findCommonAncestorTimeline that we check
> as well the start position of a timeline to cover the case where both
> target and source node forked at the same timeline number but with a
> different WAL fork position.
> I am marking this patch as ready for committer. It would be cool in
> the future to use the recovery test suite to have more advanced
> scenarios tested, but it seems a shame to block this patch because of
> that.
>
>
> Thanks a lot. Now patch looks much better.
> I found that it doesn't applies cleanly on the current master. Rebased version
> is attached.
>
> ------
> Alexander Korotkov
> Postgres Professional: http://www.postgrespro.com <http://www.postgrespro.com/>
> The Russian Postgres Company
>
>
>

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