Re: Improve handling of parameter differences in physical replication

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

From: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
To: Masahiko Sawada <masahiko.sawada@2ndquadrant.com>, Alvaro Herrera <alvherre@2ndquadrant.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2020-03-09T09:45:54Z
Lists: pgsql-hackers
On 2020-03-09 09:11, Masahiko Sawada wrote:
> I think after recovery is paused users will be better to restart the
> server rather than resume the recovery. I agree with this idea but I'm
> slightly concerned that users might not realize that recovery is
> paused until they look at that line in server log or at
> pg_stat_replication because the standby server is still functional. So
> I think we can periodically send WARNING to inform user that we're
> still waiting for parameter change and restart.

I think that would be annoying, unless you create a system for 
configuring those periodic warnings.

I imagine in a case like having set max_prepared_transactions but never 
actually using prepared transactions, people will just ignore the 
warning until they have their next restart, so it could be months of 
periodic warnings.

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



Commits

  1. Pause recovery for insufficient parameter settings

  2. Replace a macro by a function

  3. Improve handling of parameter differences in physical replication

  4. Prefer standby promotion over recovery pause.