Re: Requiring recovery.signal or standby.signal when recovering with a backup_label

At Fri, 10 Mar 2023 15:59:04 +0900, Michael Paquier <michael@paquier.xyz> wrote in 
> My apologies for the long message, but this deserves some attention,
> IMHO.
> 
> So, any thoughts?

Sorry for being late. However, I agree with David's concern regarding
the unnecessary inconvenience it introduces.  I'd like to maintain the
functionality.

While I agree that InArchiveRecovery should be activated only if
ArchiveReArchiveRecoveryRequested is true, I oppose to the notion that
the mere presence of backup_label should be interpreted as a request
for archive recovery (even if it is implied in a comment in
InitWalRecovery()). Instead, I propose that we separate backup_label
and archive recovery, in other words, we should not turn on
InArchiveRecovery if !ArchiveRecoveryRequested, regardless of the
presence of backup_label. We can know the minimum required recovery
LSN by the XLOG_BACKUP_END record.

The attached is a quick mock-up, but providing an approximation of my
thoughts. (For example, end_of_backup_reached could potentially be
extended to the ArchiveRecoveryRequested case and we could simplify
the condition..)

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center