Re: BUG #15791: WalSndCtl->sync_standbys_defined modified too late

On Sun, May 05, 2019 at 10:16:39PM -0300, Euler Taveira wrote:
> This is not a bug. This question is suitable for -hackers.
>
> Short answer is: yes. When you modify synchronous_standby_names and
> reload postgresql.conf, checkpointer get SIGHUP and it calls
> UpdateSharedMemoryConfig() -- see CheckpointerMain() circa 'if
> (got_SIGHUP)'.

There could be always some delay between the moments SIGHUP gets
processed across the different processes as we are talking mainly
about running ProcessConfigFile(OGC_SIGHUP) which can happen for
normal backends once every query, but the change will be effective.
--
Michael