Re: allow online change primary_conninfo

Hello

Thank you for review!

> ISTM that you need to update the above parts in postgresql.conf.sample.

Good catch, I forgot about conf sample.

> ISTM that you need to update the above comment in walreceiver.c.

Changed

> If primary_conninfo is set to an empty string, walreceiver just shuts down,
> not restarts. The above description in the doc is not always true.
> So I'm thinking something like the following description is better.
> Thought?
>
>     If primary_conninfo is changed while WAL receiver is running,
>     the WAL receiver shuts down and then restarts with new setting,
>     except when primary_conninfo is an empty string.

Ok, changed.
I leave primary_slot_name description as before.

> There is the case where walreceiver doesn't shut down immediately
> after the change of primary_conninfo. If the change happens while
> the startup process in paused state (e.g., by pg_wal_replay_pause(),
> recovery_min_apply_delay, recovery conflict, etc), the startup
> process tries to terminate walreceiver after it gets out of such state.
> Shouldn't this fact be documented as a note?

Hmm. Is somewhere documented that walreceiver will receive WAL while the startup process in paused state?
(didn't add such note in current version)

regards, Sergei