Re: tell master to tell it's the master - ?

Hi,

I know you don’t want to query,  but you could create your own pseudo configuration file with a query and a psql \if statement in a psql script like this:

select NOT pg_is_in_recovery() AS is_primary \gset

\if :is_primary
    \! touch /tmp/primary_at_’date +%Y%m%d%H%M%S’
\endif
\q

Run the above on each database in your cluster with a cron job/database scheduler job at the appropriate interval for your needs. This would provide a file in / tmp that identifies the primary database with a timestamp.

Hope this helps.

Regards,

Craig Jackson
On Aug 18, 2023 at 7:07 AM -0400, lejeczek <peljasz(at)yahoo(dot)co(dot)uk>, wrote:
>
>
> On 18/08/2023 11:34, Emile Amewoto wrote:
> > Hi Lejeczek,
> > What are you using to control your cluster?
> > If you are using patroni, you can use regex to grep the Leader or if you are not using any cluster manager you can do:
> >
> > SELECT Count(pid))
> >           FROM pg_stat_activity WHERE wait_event IS NOT NULL AND backend_type = ‘walsender'
> > The master will always have walsender process and the standby walreiver
> >
> > Regards,
> > Emile
> >
> > > On 18 Aug 2023, at 11:07, lejeczek <peljasz(at)yahoo(dot)co(dot)uk> wrote:
> > >
> > > Hi guys.
> > >
> > > Is it possible to configure pgSQL to announce it's being a master and not querying it?
> > > I was hoping for a file whose existence or content would confirm that and would be generated/created by pqSQL itself - am I too naive?
> > >
> > > many thanks, L.
> >
> Hi, thanks for the tip.
> I'm looking at what I wrote - perhaps I was bit vague - ... it's being a master by not querying it & via means of config/uration instead - is what wanted to ask.