Re: BUG #7549: max_connections check should query master when starting standby

On Tue, Sep 18, 2012 at 3:51 AM,  <petsku@petteriraty.eu> wrote:
> The following bug has been logged on the website:
>
> Bug reference:      7549
> Logged by:          Petteri R=E4ty
> Email address:      petsku@petteriraty.eu
> PostgreSQL version: 9.2.0
> Operating system:   Linux or OS X
> Description:
>
> On a streaming hot standby slave starting postgres:
>
>
> LOG:  database system was interrupted while in recovery at log time
> 2012-09-17 21:29:31 EEST
> HINT:  If this has occurred more than once some data might be corrupted a=
nd
> you might need to choose an earlier recovery target.
> LOG:  entering standby mode
> FATAL:  hot standby is not possible because max_connections =3D 20 is a l=
ower
> setting than on the master server (its value was 100)
> LOG:  startup process (PID 51494) exited with exit code 1
> LOG:  aborting startup due to startup process failure
>
> It was indeed the case that the limit was lower on the slave but to resol=
ve
> it I lowered the setting on the master:
>
> postgres=3D# SHOW max_connections;
>  max_connections
> -----------------
>  20
> (1 row)
>
> The slave should allow resolving the issue by not only changes on the sla=
ve
> side but by checking if the master has been updated as well.

If you change the max_connections on the master, you need to take a
fresh backup from the master and start the standby from it.

Regards,

--=20
Fujii Masao