Horton

Re: Shutdown indefinitely stuck due to unflushed FPI_FOR_HINT record

Fujii Masao <masao.fujii@gmail.com>

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From: Fujii Masao <masao.fujii@gmail.com>
To: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>
Cc: Alexander Lakhin <exclusion@gmail.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2026-03-05T23:46:15Z
Lists: pgsql-hackers

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On Thu, Mar 5, 2026 at 5:40 PM Anthonin Bonnefoy
<anthonin.bonnefoy@datadoghq.com> wrote:
> So it was relying on GetInsertRecPtr() instead of
> GetXLogInsertRecPtr(). As mentioned in the thread, GetInsertRecPtr()
> only returns the position of the last full xlog page, meaning it
> doesn't fix the issue we have where the last partial page contains a
> continuation record.
>
> Testing the XLogFlush(GetInsertRecPtr()) patch with my script, I still
> get the shutdown stuck issue.
>
> Using GetXLogInsertRecPtr() is required to make sure the last partial
> page is correctly flushed.

Since GetXLogInsertRecPtr() returns a bogus LSN and XLogFlush() does
almost nothing during recovery, I added a !RecoveryInProgress() check
as follows. I've attached the latest version of the patch and updated
the commit message.

- if (got_STOPPING)
- XLogBackgroundFlush();
+ if (got_STOPPING && !RecoveryInProgress())
+ XLogFlush(GetXLogInsertRecPtr());

Regards,

-- 
Fujii Masao

Commits

  1. Fix WAL flush LSN used by logical walsender during shutdown

  2. Use GetXLogInsertEndRecPtr in gistGetFakeLSN

  3. Fix publisher shutdown hang caused by logical walsender busy loop.