Horton

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

Kyotaro Horiguchi <horikyota.ntt@gmail.com>

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From: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
To: michael@paquier.xyz
Cc: pgsql-hackers@lists.postgresql.org
Date: 2023-09-28T03:58:51Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Delay recovery mode LOG after reading backup_label and/or checkpoint record

  2. Mention standby.signal in FATALs for checkpoint record missing at recovery

  3. XLOG file archiving and point-in-time recovery. There are still some

Attachments

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