Re: [COMMITTERS] pgsql: Allow a streaming replication standby to follow a timeline switc

On Mon, Dec 17, 2012 at 02:01:20PM +0200, Heikki Linnakangas wrote:
> Hmm, is it possible that some WAL was generated in the old master,
> and streamed to the standby, after the new master was already
> promoted? It's important to kill the old master before promoting the
> new master. Otherwise the timelines diverge, so that you have some
> WAL on the old timeline that's not present in the new master, and
> some WAL in the new master's timeline that's not present in the old
> master. In that situation, if the standby has already replicated the
> WAL from the old master, it can no longer start to follow the new
> master. I think that would match the symptoms you're seeing.
>
> I wouldn't rule out a bug in the patch either, though. Amit found a
> worrying number of bugs in his testing, and although we stamped out
> all the known bugs, it wouldn't surprise me if there's more :-(..

Will verify and reach back to you.
In my test I was doing first promote slave, and later (like 2 seconds
later, and there was no traffic, but still - later) kill master.

Best regards,

depesz

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