Horton

Re: [HACKERS] logical decoding of two-phase transactions

Ajin Cherian <itsajin@gmail.com>

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From: Ajin Cherian <itsajin@gmail.com>
To: "tanghy.fnst@fujitsu.com" <tanghy.fnst@fujitsu.com>
Cc: Peter Smith <smithpb2250@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>, vignesh C <vignesh21@gmail.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2021-05-27T02:35:21Z
Lists: pgsql-hackers 
On Thu, May 27, 2021 at 11:20 AM tanghy.fnst@fujitsu.com
<tanghy.fnst@fujitsu.com> wrote:
>
> On Wed, May 26, 2021 10:13 PM Ajin Cherian <itsajin@gmail.com> wrote:
> >
> > I've attached a patch that fixes this issue. Do test and confirm.
> >
>
> Thanks for your patch.
> I have tested and confirmed that the issue I reported has been fixed.

Thanks for confirmation. The problem seemed to be as you reported a
table not closed when a transaction was committed.
This seems to be because the function UpdateTwoPhaseState was
committing a transaction inside the function when the caller of
UpdateTwoPhaseState had
a table open in CreateSubscription. This function was newly included
in the CreateSubscription code, to handle the new use case of
two_phase being enabled on
create subscription if "copy_data = false". I don't think
CreateSubscription required this to be inside a transaction and the
committing of transaction
was only meant for where this function was originally created to be
used in the apply worker code (ApplyWorkerMain()).
So, I removed the committing of the transaction from inside the
function UpdateTwoPhaseState() and instead started and committed the
transaction
 prior to and after this function is invoked in the apply worker code.

regards,
Ajin Cherian
Fujitsu Australia

Commits

  1. Add prepare API support for streaming transactions in logical replication.

  2. Doc: minor improvements for logical replication protocol documentation.

  3. Fix test failure in 021_twophase.pl.

  4. Refactor to make common functions in proto.c and worker.c.

  5. Unify PostgresNode's new() and get_new_node() methods

  6. Fix potential buffer overruns in proto.c.

  7. Add support for prepared transactions to built-in logical replication.

  8. Refactor function parse_subscription_options.

  9. Allow enabling two-phase option via replication protocol.

  10. Don't use Asserts to check for violations of replication protocol.

  11. Improve psql tab completion for options of subcriptions and publications

  12. Rearrange logrep worker's snapshot handling some more.

  13. doc: Update information of new messages for logical replication.

  14. ALTER SUBSCRIPTION ... ADD/DROP PUBLICATION

  15. Allow pgoutput to send logical decoding messages.

  16. Refactor function parse_output_parameters.

  17. Avoid repeated decoding of prepared transactions after a restart.

  18. Fix an oversight in ReorderBufferFinishPrepared.

  19. Allow multiple xacts during table sync in logical replication.

  20. Fix replication of in-progress transactions in tablesync worker.

  21. Fix 'skip-empty-xacts' option in test_decoding for streaming mode.

  22. Use Enum for top level logical replication message types.

  23. Add support for streaming to built-in logical replication.

  24. Fix the logical streaming test.

  25. Implement streaming mode in ReorderBuffer.

  26. Extend the logical decoding output plugin API with stream methods.

  27. Store 2PC GID in commit/abort WAL recs for logical decoding