Re: Timeline following for logical slots

On 04/03/16 17:08, Craig Ringer wrote:
> I'd really appreciate some review of the logic there by people who know
> timelines well and preferably know the xlogreader. It's really just one
> function and 2/3 comments; the code is simple but the reasoning leading
> to it is not.
>

I think this will have to be work for committer at this point. I can't 
find any flaws in the logic myself so I unless somebody protests I am 
going to mark this as ready for committer.

> I've also attached an updated version of the tests posted a few days
> ago.  The tests depend on the remaining patches from the TAP
> enhancements tree so it's easiest to just get the whole tree from
> https://github.com/2ndQuadrant/postgres/tree/dev/logical-decoding-timeline-following
> (subject to regular rebases and force pushes, do not use as a base).
>
> The tests now include a test module that exposes some slots guts to SQL
> to allow the client to sync slot state from master to replica(s) without
> needing failover slots and the use of extra WAL as transport. It's very
> much for-testing-only.
>
> The new test module is used by a second round of tests to demonstrate
> the practicality of failover of a logical replication client to a
> physical replica using a base backup taken by pg_basebackup and without
> the presence of failover slots. I won't pretend it's pretty.
>

Well for testing purposes it's quite fine I think. The TAP framework 
enhancements needed for this are now in and it works correctly against 
current master.

--   Petr Jelinek                  http://www.2ndQuadrant.com/  PostgreSQL Development, 24x7 Support, Training &
Services