Re: Failover, Wal Logging, and Multiple Spares

On Tue, Aug 18, 2009 at 1:25 AM, Yaroslav Tykhiy<yar@barnet.com.au> wrote:
> Encouraged by Bruce Momjian, I tried and had some success in this area.  It
> was a controlled failover but it worked like a charm.  An obvious condition
> was that the warm standbys be in perfect sync; you can't do the trick if
> some of them received the last WAL segment while the others didn't.

It seems like it should be possible to weaken this constraint. As long
as you're careful to fail over to the slave which is the furthest
ahead in replaying WAL. All the other slaves must switch to replaying
logs from the new master before the point where it took over.

This does seem like a very useful area to explore.


--
greg
http://mit.edu/~gsstark/resume.pdf