On Fri, Feb 7, 2014 at 1:57 PM, James Sewell <james.sew...@lisasoft.com>wrote:
> I've just noticed that on PostgreSQL 9.3 I can do the following with a > master node A and a slave node B (as long as I have set > recovery_target_timeline = 'latest'): > > 1. Stop Node A > 2. Promote Node B > 3. Attach Node A as slave > > This is sufficient for my needs (I know it doesn't cover a crash), can > anyone see any potential problems with this approach? > Yes, node A could get ahead of the point where WAL forked when promoting B. In this case you cannot reconnect A to B, and need to actually recreate a node from a fresh base backup, or rewind it. pg_rewind targets the latter, postgres core is able to to the former, and depending on things like your environment and/or the size of your server, you might prefer one or the other. Regards, -- Michael
