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: Peter Smith <smithpb2250@gmail.com>
Cc: Amit Kapila <amit.kapila16@gmail.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2021-03-05T06:50:42Z
Lists: pgsql-hackers

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On Thu, Mar 4, 2021 at 9:53 PM Peter Smith <smithpb2250@gmail.com> wrote:

> [05a] Now syncing the psf file at prepare time

The patch v46-0008 does not handle spooling of streaming prepare if
the Subscription is configured for both two-phase and streaming.
I feel that it would be best if we don't support both two-phase and
streaming together in a subscription in this release.
Probably a future release could handle this. So, changing the patch to
not allow streaming and two-phase together.
This new patch v49 has the following changes.

* Don't support creating a subscription with both streaming and
two-phase enabled.
* Don't support altering a subscription enabling streaming if it was
created with two-phase enabled.
* Remove stream_prepare callback as a "required" callback, make it an
optional callback and remove all code related to stream_prepare in the
pgoutput plugin as well as in worker.c

Also fixed
* Don't support the alter of subscription setting two-phase. Toggling
of two-phase mode using the alter command on the subscription can
cause transactions to be missed and result in an inconsistent replica.

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