Re: Notify When Streaming Replication Failover Occurred (slave promoted to master).

On 2021-06-14 08:10:58 -0400, Dave Cramer wrote:
> On Sun, 13 Jun 2021 at 19:32, Avi Weinberg <AviW(at)gilat(dot)com> wrote:
>
>
> I need to take actions when Postgres streaming replication failover
> occurred.  Is there a way to be notified when Postgres slave becomes
> master?
>
> On the surface this seems like a great idea, however contemplating this a bit
> more; where would the signal come from ? Currently the only option I can think
> of is to send a NOTIFY. 
> It seems to me that the Patroni code is a better place to do this from.

I agree. That is something Patroni should do, not the database. Maybe
Patroni could be extended to invoke a script after taking some action.

I know of one program (vip_manager) which monitors patroni state and
takes action (enable/disable virtual ip addresses) - that one checks the
distributed database (etcd or whatever) periodically, AFAIK.

hp

--
_ | Peter J. Holzer | Story must make more sense than reality.
|_|_) | |
| | | hjp(at)hjp(dot)at | -- Charles Stross, "Creative writing
__/ | http://www.hjp.at/ | challenge!"