Re: warning message in standby

Simon Riggs <simon@2ndquadrant.com>

From: Simon Riggs <simon@2ndQuadrant.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Robert Haas <robertmhaas@gmail.com>, Bruce Momjian <bruce@momjian.us>, Magnus Hagander <magnus@hagander.net>, Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>, Fujii Masao <masao.fujii@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2010-06-14T17:38:40Z
Lists: pgsql-hackers
On Mon, 2010-06-14 at 11:09 -0400, Tom Lane wrote:
> Simon Riggs <simon@2ndQuadrant.com> writes:
> > Should I be downgrading Hot Standby breakages to LOG? That will
> > certainly help high availability as well.
> 
> If a message is being issued in a non-user-connected session, there
> is basically not a lot of point in WARNING or below.  It should either
> be LOG, or ERROR/FATAL/PANIC (which are probably all about the same
> thing in the startup process...)

This looks like a significant issue to me. 

Code has been written for 9.0 that assumes WARNING > LOG. I've pointed
out two places in SR code, I'm pretty sure there are others.

There is also lots of pre-existing code where we run the same code in a
backend and in a server process, for example autovacuum. In those cases,
all the WARNINGs issued in vacuum.c, for example, will all be filtered
by the current log-level scheme.

LOG is already over-used and so anything said at that level is drowned.
In many areas of code we cannot use a higher level without trauma. That
is a problem since we have no way to separate the truly important from
the barely interesting.

-- 
 Simon Riggs           www.2ndQuadrant.com