Re: max_standby_delay considered harmful

Simon Riggs <simon@2ndquadrant.com>

From: Simon Riggs <simon@2ndQuadrant.com>

To: Robert Haas <robertmhaas@gmail.com>

Cc: Fujii Masao <masao.fujii@gmail.com>, Andres Freund <andres@anarazel.de>, Florian Pflug <fgp@phlo.org>, Dimitri Fontaine <dfontaine@hi-media.com>, Tom Lane <tgl@sss.pgh.pa.us>, pgsql-hackers@postgresql.org, Bruce Momjian <bruce@momjian.us>, Greg Smith <greg@2ndquadrant.com>, Josh Berkus <josh@agliodbs.com>

Date: 2010-05-12T13:15:11Z

Lists: pgsql-hackers

On Wed, 2010-05-12 at 08:52 -0400, Robert Haas wrote:
> On Wed, May 12, 2010 at 7:26 AM, Simon Riggs <simon@2ndquadrant.com> wrote:
> > On Wed, 2010-05-12 at 07:10 -0400, Robert Haas wrote:
> >
> >> I'm not sure what to make of this.  Sometimes not shutting down
> >> doesn't sound like a feature to me.
> >
> > It acts exactly the same in recovery as in normal running. It is not a
> > special feature of recovery at all, bug or otherwise.
> 
> Simon, that doesn't make any sense.  We are talking about a backend
> getting stuck forever on an exclusive lock that is held by the startup
> process and which will never be released (for example, because the
> master has shut down and no more WAL can be obtained for replay).  The
> startup process does not hold locks in normal operation.

When I test it, startup process holding a lock does not prevent shutdown
of a standby. 

I'd be happy to see your test case showing a bug exists and that the
behaviour differs from normal running.

-- 
 Simon Riggs           www.2ndQuadrant.com