Re: recovery_connections cannot start (was Re: master in standby mode croaks)

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>, Simon Riggs <simon@2ndquadrant.com>, Kevin Grittner <Kevin.Grittner@wicourts.gov>, Fujii Masao <masao.fujii@gmail.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2010-04-24T00:00:03Z
Lists: pgsql-hackers
Robert Haas <robertmhaas@gmail.com> writes:
> On Fri, Apr 23, 2010 at 7:28 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> I would expect that they'll get an error message that makes it clear
>> enough what to do ;-). In any case, changing the name is hardly going
>> to fix things so that 8.4 settings will still work, so why are you
>> giving that case as an argument for it?

> Principle of obvious breakage.

And?  If we do it by adding the new variable while not renaming
archive_mode, then I'd expect an 8.4 configuration to yield an error
along the lines of

ERROR: invalid combination of configuration parameters
HINT: To turn on archive_mode, you must set wal_mode to "archive" or "hot_standby".

(precise wording open to debate, but clearly we can do at least this
well) whereas if we rename archive_mode, it's unlikely we can do better
than

ERROR: unrecognized parameter "archive_mode"

Do you really think the second one is going to make any user happier
than the first?

			regards, tom lane