Horton

Re: BUG #16643: PG13 - Logical replication - initial startup never finishes and gets stuck in startup loop

Peter Eisentraut <peter.eisentraut@2ndquadrant.com>

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From: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
To: Tom Lane <tgl@sss.pgh.pa.us>, Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: Henry Hinze <henry.hinze@gmail.com>, pgsql-bugs@lists.postgresql.org
Date: 2020-10-01T17:24:17Z
Lists: pgsql-bugs 
On 2020-09-30 23:52, Tom Lane wrote:
> One thing I noticed while trying to trace this down is that while the
> initial table sync is happening, we have *both* a regular
> walsender/walreceiver pair and a "sync" pair, eg
> 
> postgres  905650  0.0  0.0 186052 11888 ?        Ss   17:12   0:00 postgres: logical replication worker for subscription 16398
> postgres  905651 50.1  0.0 173704 13496 ?        Ss   17:12   0:09 postgres: walsender postgres [local] idle
> postgres  905652  104  0.4 186832 148608 ?       Rs   17:12   0:19 postgres: logical replication worker for subscription 16398 sync 16393
> postgres  905653 12.2  0.0 174380 15524 ?        Ss   17:12   0:02 postgres: walsender postgres [local] COPY

That's normal.  You could also have even more if tables are syncing in 
parallel.

-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Commits

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

  2. Review logical replication tablesync code

  3. Restore replication protocol's duplicate command tags