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To: "Marc G. Fournier" <scrappy@hub.org>
cc: pgsql-hackers@postgreSQL.org
Subject: Re: [ADMIN] postgresql in FreeBSD jails: proposal 
In-reply-to: <fmmqfh$buq$3@news.hub.org> 
References: <1200501702.478e33c61b74e@webmail.telus.net>
	<fmmqfh$buq$3@news.hub.org>
Comments: In-reply-to "Marc G. Fournier" <scrappy@hub.org>
	message dated "Thu, 17 Jan 2008 05:52:50 +0000"
Date: Thu, 17 Jan 2008 01:12:54 -0500
Message-ID: <4089.1200550374@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
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"Marc G. Fournier" <scrappy@hub.org> writes:
> mischa_sandberg@telus.net (Mischa Sandberg) writes:
>> Unfortunately, with multiple jails running PG servers and (due to app
>> limitations) all servers having same PGPORT, you get the situation that
>> when jail#2 (,jail#3,...) server comes up, it:
>> - detects that there is a shm seg with ipc key 5432001
>> - checks whether the associated postmaster process exists (with kill -0)
>> - overwrites the segment created and being used by jail #1

> Easiest fix: change the UID of the user running the postmaster (ie. pgsql) so
> that each runs as a distinct UID (instead of distinct PGPORT) ... been doing 
> this since moving to FreeBSD 6.x ... no patches required ...

Sure, but in the spirit of "belt and suspenders too", I'd think that
doing that *and* something like Mischa's proposal wouldn't be bad.

(BTW, as far as I saw the original post only went to -hackers
... there's something messed up about your reply.)

			regards, tom lane