Re: [HACKERS] [PATCH] Document the order of changing certainsettings when using hot-standby servers

Aleksander, Yorick,

* Aleksander Alekseev (a.alekseev@postgrespro.ru) wrote:
> > The attached patch updates the hot-standby documentation (in the high
> > availability section) so it explicitly mentions that certain settings
> > need to be applied to servers in a particular order. For example, it
> > states that if you increase a certain setting (e.g. max_connections)
> > you need to do so on a primary first, before applying it to any
> > secondaries.
>
> I'm sorry to inform you that your description of max_connection is,
> lets say, not quite accurate. I've just increased max_connections on a
> standby without doing anything on a master and nothing wrong happened.

Right, the logic there is reversed- reduction has to be done on the
primary first and then WAL replayed on the replica, while increasing has
to be done on the secondary first and then on the primary.

I do think that we should add the (correct!) information into the docs
explicitly, perhaps even as a 'Note', since it can be quite confusing
otherwise.

Thanks!

Stephen