Re: Is Recovery actually paused?

At Tue, 9 Feb 2021 12:27:21 +0530, Bharath Rupireddy <bharath(dot)rupireddyforpostgres(at)gmail(dot)com> wrote in
> What I meant was that if we were to add waiting logic inside
> pg_wal_replay_pause, we should also have a timeout with some default
> value, to avoid pg_wal_replay_pause waiting forever in the waiting
> loop. Within that timeout, if the recovery isn't paused,
> pg_wal_replay_pause will return probably a warning and a false(this
> requires us to change the return value of the existing
> pg_wal_replay_pause)?

I thought that rm_redo finishes shortly unless any trouble
happens. But on second thought, I found that I forgot a case of a
recovery-conflict. So as you pointed out, pg_wal_replay_pause() needs
a flag 'wait' to wait for a pause established. And the flag can be
turned into "timeout".

# And the prevous verision had another silly bug.

> To avoid changing the existing API and return type, a new function
> pg_get_wal_replay_pause_state is introduced.

I mentioned about IN parameters, not OUTs. IN parameters can be
optional to accept existing usage. pg_wal_replay_pause() is changed
that way in the attached.

If all of you still disagree with my proposal, I withdraw it.

regards.

--
Kyotaro Horiguchi
NTT Open Source Software Center