Horton

Re: odd buildfarm failure - "pg_ctl: control file appears to be corrupt"

Michael Paquier <michael@paquier.xyz>

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From: Michael Paquier <michael@paquier.xyz>
To: David Steele <david@pgmasters.net>
Cc: Thomas Munro <thomas.munro@gmail.com>, Stephen Frost <sfrost@snowman.net>, Daniel Gustafsson <daniel@yesql.se>, "Anton A. Melnikov" <aamelnikov@inbox.ru>, Tom Lane <tgl@sss.pgh.pa.us>, Andres Freund <andres@anarazel.de>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2023-10-12T23:15:56Z
Lists: pgsql-hackers 
On Thu, Oct 12, 2023 at 10:41:39AM -0400, David Steele wrote:
> After some more thought, I think we could massage the "pg_control in
> backup_label" method into something that could be back patched, with more
> advanced features (e.g. error on backup_label and pg_control both present on
> initial cluster start) saved for HEAD.

I doubt that anything changed in this area would be in the
backpatchable zone, particularly as it would involve protocol changes
within the replication commands, so I'd recommend to focus on HEAD.
Backward-compatibility is not much of a conern as long as the backend
is involved.  The real problem here would be on the frontend side and
how much effort we should try to put in maintaining the code of
pg_basebackup compatible with older backends.
--
Michael

Commits

  1. Try to handle torn reads of pg_control in frontend.

  2. Acquire ControlFileLock in relevant SQL functions.