Horton

RE: Logical replication timeout problem

Wei Wang (Fujitsu) <wangw.fnst@fujitsu.com>

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From: "wangw.fnst@fujitsu.com" <wangw.fnst@fujitsu.com>
To: "kuroda.hayato@fujitsu.com" <kuroda.hayato@fujitsu.com>, Masahiko Sawada <sawada.mshk@gmail.com>
Cc: Amit Kapila <amit.kapila16@gmail.com>, Peter Smith <smithpb2250@gmail.com>, Fabrice Chapuis <fabrice636861@gmail.com>, Simon Riggs <simon.riggs@enterprisedb.com>, Petr Jelinek <petr.jelinek@enterprisedb.com>, "tanghy.fnst@fujitsu.com" <tanghy.fnst@fujitsu.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Ajin Cherian <itsajin@gmail.com>
Date: 2022-03-28T06:11:08Z
Lists: pgsql-hackers

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On Mon, Mar 28, 2022 at 9:56 AM Kuroda, Hayato/黒田 隼人 <kuroda.hayato@fujitsu.com> wrote:
> Dear Wang-san,
Thanks for your comments.

> Thank you for updating!
> ...but it also cannot be applied to current HEAD
> because of the commit 923def9a533.
> 
> Your patch seems to conflict the adding an argument of
> logicalrep_write_insert().
> It allows specifying columns to publish by skipping some columns in
> logicalrep_write_tuple()
> which is called from logicalrep_write_insert() and logicalrep_write_update().
Thank for your kindly reminder.
Rebase the patch.

> Do we have to consider something special case for that?
> I thought timeout may occur if users have huge table and publish few columns,
> but it is corner case.
I think maybe we do not need to deal with this use case.
The maximum number of table columns allowed by PG is 1600
(macro MaxHeapAttributeNumber), and after loop through all columns in the
function logicalrep_write_tuple, the function OutputPluginWrite will be invoked
immediately to actually send the data to the subscriber. This refreshes the
last time the subscriber received a message.
So I think this loop will not cause timeout issues.

Regards,
Wang wei

Commits

  1. Fix the logical replication timeout during large DDLs.

  2. Fix the logical replication timeout during large transactions.

  3. Rethink the delay-checkpoint-end mechanism in the back-branches.

  4. Revert "Logical decoding of sequences"

  5. Skip empty transactions for logical replication.

  6. Allow specifying column lists for logical replication

  7. Add decoding of sequences to built-in replication

  8. Fix ABI break introduced by commit 4daa140a2f.

  9. Lag tracking for logical replication