public inbox for [email protected]  

help / color / mirror / Atom feed

From: Maksim.Melnikov <[email protected]>
To: Alexander Korotkov <[email protected]>
Cc: [email protected]
Subject: Re: Incorrect checksum in control file with pg_rewind test
Date: Tue, 12 May 2026 11:30:55 +0300
Message-ID: <[email protected]> (raw)
In-Reply-To: <CAPpHfdsXkEWUeLUG4zh9q=hjpsOCMgsbN_XZh-6JL0z1NaNMqQ@mail.gmail.com>
References: <[email protected]>
	<[email protected]>
	<CAPpHfdsXkEWUeLUG4zh9q=hjpsOCMgsbN_XZh-6JL0z1NaNMqQ@mail.gmail.com>


On 4/21/26 15:12, Alexander Korotkov wrote:
> Thank you for spotting this issue and proposing a patch.  The fork
> builds don't have this problem, because fork replicated contents of
> LocalControlFile to the new process.  And the postmaster has
> consistent snapshot of control file as there is no concurrent process
> which could write it and that moment.  But EXEC_BACKEND, even with
> your patch, may end up different processes with different contents of
> LocalControlFile.  I don't see it could cause a material bug right
> now, but I see this as undesirable divergence between fork and
> EXEC_BACKEND behaviors.  I propose an alternative approach copy the
> contents of control file to the new process via BackendParameters.
> This approach solves two problems at once: no torn reads, and no
> divergence between fork and EXEC_BACKEND.

Hi, Alexander!

Thanks for response! Your patch LGTM.

Best regards,
Maksim Melnikov

view thread (6+ messages)

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: [email protected]
  Cc: [email protected], [email protected], [email protected]
  Subject: Re: Incorrect checksum in control file with pg_rewind test
  In-Reply-To: <[email protected]>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox