Re: pg_upgrade improvements

On Wed, Apr 04, 2012 at 07:26:58PM -0700, Harold Giménez wrote:
> There could be incoming connections for a number of
> reasons: either the user or the user's applications are reestablishing
> connections, or something like collectd on the localhost attempts to
> connect during that small window.

Well, we did address this in PG 9.2 by having pg_upgrade use a
non-default port number when starting servers, 50432.  You can do that
too in PG 9.1 by just specifying non-default port numbers when you run
pg_upgrade.  We do start the server with a special --binary-upgrade
mode, and we could do all sorts of connection limits in that mode, but
having the port number be different seemed the clearest solution.