[Bucardo-general] Two-Phase Commit

[David E. Wheeler]

On Oct 31, 2012, at 12:51 PM, Greg Sabino Mullane <greg at endpoint.com> wrote:

>> At a quick glance, I see no support for two-phase commit 
>> in the 5.0 code base.
> 
> Correct. Big gotcha is 2PC does not work with LISTEN/NOTIFY.

The docs appear to say that the issue is LISTEN/UNLISTEN, but not NOTIFY.

  http://www.postgresql.org/docs/current/static/sql-prepare-transaction.html

Do the connections doing the copying do LISTEN or NOTIFY? I know the triggers in the underlying tables send NOTIFYs, but those are separate connections, no? And besides, the triggers are disconnected during a sync, right?

> The track will not be updated, so the next time Bucardo runs it will 
> get all databases in sync again. It's debatable if we really want the 
> behavior that one down db blocks all the rest, given our highly 
> async nature.

Would be a useful feature, I think, for those who want things to be a bit more synchronous.

Best,

David