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.paquier@gmail.com
> <mailto:michael.paquier@gmail.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
>
>
>

-- 
Teodor Sigaev                                   E-mail: teodor@sigaev.ru
  WWW: http://www.sigaev.ru/