Re: max_standby_delay considered harmful

Bruce Momjian <bruce@momjian.us>

From: Bruce Momjian <bruce@momjian.us>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>, Tom Lane <tgl@sss.pgh.pa.us>, Simon Riggs <simon@2ndquadrant.com>, pgsql-hackers@postgresql.org
Date: 2010-05-06T00:29:52Z
Lists: pgsql-hackers
Robert Haas wrote:
> >> If you have the monitoring in place to sensibly monitor the delay
> >> between primary and standby, and you want a limit on that, you can put
> >> together a script to flip the switch in postgresql.conf if the standby
> >> falls too much behind.
> >>
> >> It would be nice to make that settable per-session, BTW. Though as soon
> >> as you have one session using -1, the standby could fall behind. Still,
> >> it might be useful if you run both kinds of queries on the same standby.
> >
> > +1 for a boolean
> >
> > We are not supposed to be designing the behavior during beta, which is
> > exactly what we are doing, and I don't think we even know what behavior
> > we want, let alone have we implemented it. ?I think a boolean is very
> > clear and it gives you the chance to optimize _one_ case, which is
> > enough for 9.0. ?Let's revisit this for 9.1 when we will know a lot more
> > than we do now.
> 
> The existing behavior is probably not optimal, but I'm not seeing what
> benefit we get out of neutering it.

We get to design it right, or maybe not need it at all in 9.1.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com