Horton

Re: Skipping logical replication transactions on subscriber side

David G. Johnston <david.g.johnston@gmail.com>

View thread View on postgr.es
From: "David G. Johnston" <david.g.johnston@gmail.com>
To: Masahiko Sawada <sawada.mshk@gmail.com>
Cc: Peter Eisentraut <peter.eisentraut@enterprisedb.com>, Amit Kapila <amit.kapila16@gmail.com>, "tanghy.fnst@fujitsu.com" <tanghy.fnst@fujitsu.com>, vignesh C <vignesh21@gmail.com>, Greg Nancarrow <gregn4422@gmail.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: 2022-01-25T14:58:00Z
Lists: pgsql-hackers 
On Tue, Jan 25, 2022 at 7:47 AM Masahiko Sawada <sawada.mshk@gmail.com>
wrote:

> Yeah, I think it's a good idea to clear the subskipxid after the first
> transaction regardless of whether the worker skipped it.
>
>
So basically instead of stopping the worker with an error you suggest
having the worker continue applying changes (after resetting subskipxid,
and - arguably - the ?_error_* fields).  Log the transaction xid mis-match
as a warning in the log file as opposed to an error.

I was supposing to make it an error and have the worker stop again since in
a system where the xid is verified and the code is bug-free I would expect
the situation to be a "can't happen" one and I'd rather error in that
circumstance than warn.  The DBA will have to go and ALTER SUBSCRIPTION
SKIP (xid = NONE) to get the worker working again but I find that
acceptable in this case.

David J.

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