Обсуждение: BUG #18942 and BUG #18938 solution available in Pg16 latest release 16.10

 

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On Thu, 23 Oct 2025 at 10:14, Ishan Arunkumar Joshi
<ishan.joshi@netcracker.com> wrote:
> we were facing issue while performing logical replication error as follows which are similar to BUG 18942 and 18938
inPG v16.9. We gone through the Release note for PG v16.10 but not able to find the solution for above mentioned bug
releasedor not. 
>
> can you please help to understand if the solution is available for BUG 18942 and 18938  in latest PG16 release 16.10.

Yes. Mentioned in: https://www.postgresql.org/docs/16/release-16-10.html

"Avoid infinite wait in logical decoding when reading a
partially-written WAL record (Vignesh C) §

If the server crashes after writing the first part of a WAL record
that would span multiple pages, subsequent logical decoding of the WAL
stream would wait for data to arrive on the next WAL page. That might
never happen if the server is now idle."

David

On Wed, Oct 22, 2025, at 6:36 PM, David Rowley wrote:
> On Thu, 23 Oct 2025 at 10:14, Ishan Arunkumar Joshi
> <ishan.joshi@netcracker.com> wrote:
>> we were facing issue while performing logical replication error as follows which are similar to BUG 18942 and 18938
inPG v16.9. We gone through the Release note for PG v16.10 but not able to find the solution for above mentioned bug
releasedor not. 
>>
>> can you please help to understand if the solution is available for BUG 18942 and 18938  in latest PG16 release
16.10.
>
> Yes. Mentioned in: https://www.postgresql.org/docs/16/release-16-10.html
>
> "Avoid infinite wait in logical decoding when reading a
> partially-written WAL record (Vignesh C) §
>

This is not the current fix. The one for the referred bugs is:

Avoid re-distributing cache invalidation messages from other transactions
during logical replication (vignesh C)

Our previous round of minor releases included a bug fix to ensure that
replication receiver processes would respond to cross-process cache
invalidation messages, preventing them from using stale catalog data while
performing replication updates. However, the fix unintentionally made them also
redistribute those messages again, leading to an exponential increase in the
number of invalidation messages, which would often end in a memory allocation
failure. Fix by not redistributing received messages.

The commit for v16 is b2ae077205e.


--
Euler Taveira
EDB   https://www.enterprisedb.com/

Hello David,

Thanks for your reply but I think that is separate issue that is mentioned in the release note. As the bug are related
tomemory allocation while logical replication slots is been configured ("invalid memory alloc request size 1803546384")
where the release note is related to partialy written WAL which is not the use case.
 

Thanks & Regards,
-------------------------
Ishan Joshi

-----Original Message-----
From: David Rowley <dgrowleyml@gmail.com>
Sent: Thursday, October 23, 2025 3:07 AM
To: Ishan Arunkumar Joshi <ishan.joshi@netcracker.com>
Cc: pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #18942 and BUG #18938 solution available in Pg16 latest release 16.10

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On Thu, 23 Oct 2025 at 10:14, Ishan Arunkumar Joshi <ishan.joshi@netcracker.com> wrote:
> we were facing issue while performing logical replication error as follows which are similar to BUG 18942 and 18938
inPG v16.9. We gone through the Release note for PG v16.10 but not able to find the solution for above mentioned bug
releasedor not.
 
>
> can you please help to understand if the solution is available for BUG 18942 and 18938  in latest PG16 release
16.10.

Yes. Mentioned in: https://www.postgresql.org/docs/16/release-16-10.html

"Avoid infinite wait in logical decoding when reading a partially-written WAL record (Vignesh C) §

If the server crashes after writing the first part of a WAL record that would span multiple pages, subsequent logical
decodingof the WAL stream would wait for data to arrive on the next WAL page. That might never happen if the server is
nowidle."
 

David


________________________________
The information transmitted herein is intended only for the person or entity to which it is addressed and may contain
confidential,proprietary and/or privileged material. Any review, retransmission, dissemination or other use of, or
takingof any action in reliance upon, this information by persons or entities other than the intended recipient is
prohibited.If you received this in error, please contact the sender and delete the material from any computer.