Semaphores In SCO UNIX (Progress 4GL related)

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Oct 4, 2002, 5:06:00 AM10/4/02
Hi all,

Firstly, I apologize for the cross-posting, but I really am in desperate
need of a solution to my problem.

I am trying to increase the amount of memory available to Progress 4GL,
using the buffers command (-B). So far I have increased the size from 50kb,
to 20,000kb, which is noticably better, but my aim is to at least double
this figure again.

However, if I increase my buffers value anymore, I have 'semaphore' errors.
Either the database won't run, with the following error:

SERVER Semaphore limit exceeded

Or only a few users will be able to log on before remaining users are
blocked with a similar error.

The SCO OpenServer Handbook seems less than helpful in explaining if and how
I can increase the amount of semaphores on my system to accomodate the
buffers increase. I'm sure you must be able to accomplish this as I've heard
of people using buffers of 170,000kb plus.

I'm relatively inexperienced with Unix, growing up in a Microsoft world (!),
so would be very appreciative of newbie explanations for what exactly is
happening here.

Thank you very much.



Oct 4, 2002, 5:13:22 AM10/4/02
"Elliot" <> wrote in message

I am using SCO OpenServer Enterprise v5.0.4 with Progress v8.2C


Oct 4, 2002, 7:28:31 AM10/4/02
"Elliot" <> wrote in message

Currently, I'm under the impression I need to alter the semaphore values


Then use idbuild to rebuild the kernel.

This sounds quite drastic. How long does it take to rebuild? Are their
potentially many problems which could completely kill the server? Do I just
simply reboot after a rebuild?

Thanks all.

Steve Gardiner

Oct 4, 2002, 12:09:34 PM10/4/02
This is correct. We ran Progress on OpenServer for years until upgrading to
UnixWare. Just adjust the Semaphore parmaeters, relink and reboot. Relinking
should only take a couple minutes at most if you have a speedy machine. There
are several articles in the Progress knowledge base about unix tuning, look at for more info.

It's possible you'll need to adjust some of the parameters larger than the max
allowed. This is not really a big deal, you just have to edit the max value
larger in /etc/conf/cf.d/mtune. We had to do this with 2-3 of the semaphore

You may need or want to adjust other Unix related parameters to improve
performance too. Adjusting -B in progress helps, but if the OpenServer isn't
tuned well, you'll still have performance issues. Parms such as NBUF, NHBUF,

Good luck

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