Re: semaphore usage "port based"? - Mailing list pgsql-hackers

'k, an excerpt from a thread on the freebsd lists ... I'm not sure how to 
answer:

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On Sun, Apr 02, 2006 at 05:24:10PM -0300, Marc G. Fournier wrote:
> On Sun, 2 Apr 2006, Kris Kennaway wrote:
>
> >>Right, but why are they doing it *consistently* in FreeBSD 6.x, when 
they
> >>never did it in FreeBSD 4.x?  I have postmaster processes running on 
the
> >>FreeBSD box as far back as November 27th, 2005 ... and have *never*
> >>experienced this problem ... so it isn't PostgreSQL that has changed,
> >>something in FreeBSD has changed :(
> >
> >You'll need to do some debugging to find out which of the two causes
> >of EINVAL are true here (or some undocumented cause).
>
> 'k, right now, the checks in PostgreSQL are just seeing if the result of
> semctl < 0 ... i see from the man page what 'two values' of EINVAL you 
are
> referring to ... but, if they both return the same ERRNO, how do I
> determine which of the two is the cause of the problem? :(

Evaluate context: what other semaphore operations have been performed
previously?

Kris
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is there any easy way to answer this?  I'm getting the Invalid Argument 
error for SETVAL and IPC_RMID ...

On Sun, 2 Apr 2006, Marc G. Fournier wrote:

>
> I've got an odd issue that I'm not sure how to fix ... or, if fixing is even 
> possible ...
>
> I just put into place a FreeBSD 6.x server ... it has 2 jails running on it, 
> and inside of each, I'm trying to run a PostgreSQL 7.4.12 server (OpenACS 
> requirement, no choice there) ...
>
> Now, on my older FreeBSD 4.x servers, I have about 17 PostgreSQL servers 
> (some 7.2, some 7.4, some 8.x) ... and they all run fine, and they all run on 
> port 5432 ...
>
> Now, something in FreeBSD has changed since 4.x that, if you start up a 
> second PostgreSQL server on port 5432, the first one starts to generate 
> "semctl: Invalid argument" errors ...
>
> If I move one to port 5433, both run great ...
>
> Now, since this *did* work fine with 4.x, the FreeBSD developers have 
> obviously changed something that is causing it not to work ... but, since 
> 'changing port' appears to fix it, I'm wondering if there is something in our 
> Semaphore creation code that can be tweaked so that the semaphore side of 
> things *thinks* its running on a different port, but it still responses to 
> port 5432?
>
> Or, more simply, I think ... is there somewhere in the Semaphore code that is 
> using the port # as a 'seed'?
>
> I'm trying to attack things from the FreeBSD side too, to find out what has 
> changed, and how to fix it, but figured I might be able to come up with a 
> quicker fix from this group ...
>
> Thx ...
>
>
> ----
> Marc G. Fournier           Hub.Org Networking Services (http://www.hub.org)
> Email: scrappy@hub.org           Yahoo!: yscrappy              ICQ: 7615664
>
> ---------------------------(end of broadcast)---------------------------
> TIP 2: Don't 'kill -9' the postmaster
>

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Marc G. Fournier           Hub.Org Networking Services (http://www.hub.org)
Email: scrappy@hub.org           Yahoo!: yscrappy              ICQ: 7615664