You are correct - freebsd have indeed a global shm space which I don't think
is fixed in 5.x yet. We have run up to 4 postgresql in jails for our testing
and it just-works(tm) if we choose a different port for each database
instance.
It might still be a good idea for postgresql to be able to detect this
collision without crashing each others backend or doing other weird stuff.
Maybe a dedicated bit in the shm space could be flipped by the new
postmaster so it could see if it was flipped back again - this would allow
it to abort gracefully with a "Other postmaster active in my shared memory"
error.
Any other ideas ? It should be trivally to implement something to handle it
better.
Nicolai Petri
----- Original Message -----
From: "Achilleus Mantzios" <achill@matrix.gatewaynet.com>
To: "Alexander Rusinov" <boot@eurocom.od.ua>
Cc: <pgsql-bugs@postgresql.org>
Sent: Wednesday, April 27, 2005 3:53 PM
Subject: Re: [BUGS] BUG #1632: Several jailed PostgreSQL instances.
>O Alexander Rusinov Ýãñáøå óôéò Apr 27, 2005 :
>
>>
>> The following bug has been logged online:
>>
>> Bug reference: 1632
>> Logged by: Alexander Rusinov
>> Email address: boot@eurocom.od.ua
>> PostgreSQL version: 7.4.7
>> Operating system: FreeBSD 5.4-PRERELEASE i386
>> Description: Several jailed PostgreSQL instances.
>> Details:
>
> Excuse me if i missed some episodes, but to the best of my knowledge,
> FreeBSD IPC is not jailified.
> There have been talks and talks on the matter on both lists,
> and it seems
> the only way to go is to start the jailed postgresql instances
> to listen to different ports.
>
> Tom and others, please correct me if situation now with FreeBSD 5.3+ has
> changed.
>