Horton

Re: Skipping logical replication transactions on subscriber side

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: Masahiko Sawada <sawada.mshk@gmail.com>
Cc: "tanghy.fnst@fujitsu.com" <tanghy.fnst@fujitsu.com>, vignesh C <vignesh21@gmail.com>, Greg Nancarrow <gregn4422@gmail.com>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>, "houzj.fnst@fujitsu.com" <houzj.fnst@fujitsu.com>, "osumi.takamichi@fujitsu.com" <osumi.takamichi@fujitsu.com>, Alexey Lesovsky <lesovsky@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2022-01-21T12:13:12Z
Lists: pgsql-hackers 
On Fri, Jan 21, 2022 at 5:25 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> On Fri, Jan 21, 2022 at 10:10 AM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
> >
>
> Few things that I think we can improve in 028_skip_xact.pl are as follows:
>
> After CREATE SUBSCRIPTION, wait for initial sync to be over and
> two_phase state to be enabled. Please see 021_twophase. For the
> streaming case, we might be able to ensure streaming even with lesser
> data. Can you please try that?
>

I noticed that the newly added test by this patch takes time is on the
upper side. See comparison with the subscription test that takes max
time:
[17:38:49] t/028_skip_xact.pl ................. ok     9298 ms
[17:38:59] t/100_bugs.pl ...................... ok    11349 ms

I think we can reduce time by removing some stream tests without much
impacting on coverage, possibly related to 2PC and streaming together,
and if you do that we probably don't need a subscription with both 2PC
and streaming enabled.

-- 
With Regards,
Amit Kapila.

Commits

  1. Test ALIGNOF_DOUBLE==4 compatibility under ALIGNOF_DOUBLE==8.

  2. Reorder subskiplsn in pg_subscription to avoid alignment issues.

  3. Add ALTER SUBSCRIPTION ... SKIP.

  4. Optionally disable subscriptions on error.

  5. Update docs of logical replication for commit 8d74fc96db.

  6. Respect permissions within logical replication.

  7. Fix regression test failure caused by commit 8d74fc96db.

  8. Add a view to show the stats of subscription workers.

  9. Add logical change details to logical replication worker errcontext.

  10. Rename LOGICAL_REP_MSG_STREAM_END to LOGICAL_REP_MSG_STREAM_STOP.

  11. Fix typo in protocol.sgml.

  12. Remove unused argument in apply_handle_commit_internal().

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

  14. Reorder pg_sequence columns to avoid alignment issue