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Q: How to run multiple instances of an application? On a Server? ( No Answer,   6 Comments )
Subject: How to run multiple instances of an application? On a Server?
Category: Computers > Hardware
Asked by: jjpaul-ga
List Price: $10.00
Posted: 10 Apr 2004 23:06 PDT
Expires: 10 May 2004 23:06 PDT
Question ID: 328352
For a multimedia installation I need to run more instances of the same
application (each session of the program has specific parameters and
patches and files associated). Considering that I need multiple video
outputs, each connected to a different session, how  can I achieve
Multiple workstations won't work (money and space limitations), so
would a server be a better idea?

Request for Question Clarification by mathtalk-ga on 11 Apr 2004 16:56 PDT
Hi, jjpaul-ga:

I'm not sure there's enough information yet to say whether a "server"
class PC versus a "workstation" would address the concern you have.

You've referred to the multiple instances of the same application as
"sessions", which is often the word used to associate a Windows
application with an interactive "desktop" environment.  Depending on
how much user interaction may be required, the difference between a
"server" and a "workstation" may not be material.

A multimedia application like Powerpoint is written in such a way that
it relies upon user interaction to resolve unexpected conflicts.  A
fair amount of "automated" behavior can be programmed (e.g. using MS
Office Automation, Windows Host scripting, etc.), but to try and keep
multiple instances going at the same time would quickly turn into a
stupendous juggling feat.

Depending on your hardware requirements (how many video outputs?) and
operating system restrictions (umm, Windows?), you may be looking at a
"server" in the sense of multi-user/multiprocessor boxes like the
Citrix MetaFrame application:

I look forward to hearing more specifics about your project.

regards, mathtalk-ga

Clarification of Question by jjpaul-ga on 12 Apr 2004 02:19 PDT
Hiya. I knew that my wording would have caused confusion, so I'll add more details.

Installation involves the *simultaneous* projection of stuff done with
a program that generates automatic images (Mac OS 9.2), on the lateral
walls of a cube. The projection is done from the inside, where both
the server, as well as the projectors are to be installed. This
particular installation will call for 4 video outputs, each of which
will carry the signal from one *different* instance of this program.
Hope this clarifies somewhat my question.

Thank you!


Request for Question Clarification by mathtalk-ga on 12 Apr 2004 17:32 PDT
Hi, "JJ":

Given that your application (does it have a name?) runs under Mac OS
9.2, we clearly will want to choose a Macintosh computer.  But I'm
wondering what is meant by a "server"?

There are a variety of Macintosh computers and multimonitor support
has been in Apple operating systems for some time.  Mac OS 9.2 in
particular should be fine, provided the video adapters you choose have
compatible drivers.  Some of the newest cards will only target Mac OS

You describe the installation as projecting images onto four walls of
a cube, so I guess it's a given you'll need at least four video
projectors of some type, external to the computer itself.  Perhaps you
should define the graphic resolutions of these four displays, and also
provide some additional information about the application that will
(in four separate instances) feed images to them.  A higher resolution
and more rapidly changing image would suggest the need for a
high-capability video card.

The Macintosh marketplace is smaller than for Windows, but there are a
number of options available:  the type of adapter (PCI or PCMCIA), the
type of signal (VGA, DVI, SVideo), and number of displays per adapter
(single vs. dual-head).

If you are looking to create the installation on a budget, perhaps a
good starting point is what equipment you may already have to work
with.  Most Mac's come with a fairly limited amount of video memory,
but fortunately some of the newer adapters will provide 32MB or more
of their own video memory.

Another reason to decide on the computer model is to begin planning
for heat dissipation.  Video cards tend to run fairly hot, esp. the
high performance ones.

regards, mathtalk-ga
There is no answer at this time.

Subject: Re: How to run multiple instances of an application? On a Server?
From: topbanana-ga on 12 Apr 2004 11:39 PDT
I'm pretty sure this isn't possible in 9.2, since OS X is based on
unix it should be possible within that. Perhaps you should upgrade?
Subject: Re: How to run multiple instances of an application? On a Server?
From: topbanana-ga on 12 Apr 2004 11:43 PDT
Come to think of it, it's been a while since I used 9.2 and I guess
it's down to the application, but have you tried duplicating the
entire application folder and then running a copy of each app by
starting one from each folder?
Subject: Re: How to run multiple instances of an application? On a Server?
From: jjpaul-ga on 13 Apr 2004 02:04 PDT
Hi there... the program in question is part of UI Software's family of
graphic apps and they do run *only* in 9.2, as they haven't been
ported to OSX yet.

a) the memory requirements each instance of the program asks for
b) that I need 4 separate physical outputs, each accessing one
instance of the running app, and most machines only have 2 outputs
(which output the same signal BTW)

it is therefore almost mandatory that I manage to find another 4-in-1
solution, so to speak. Maybe it's impossible, I understand, but I
ain't giving up without a fight ;)

As far as available equipm't that is available at the moment, it is
really limited. An old & trusty G3 400 w/ 512 Mb memory (quite
sufficient to run *one* instance of the program without glitches), and
a newer G4 DP 1.25, but it is only bootable in OSX (9.2 emulation).
Still on the hunt for projectors but won't commit yet, given the other
problms I need to solve.

Thank you again,

"JJ" Paul
Subject: Re: How to run multiple instances of an application? On a Server?
From: mathtalk-ga on 13 Apr 2004 09:01 PDT
Hi, jjpaul-ga:

The basic approach to adding extra video outputs to a Macintosh is by
putting video adapter cards into the PCI slots (on a PowerMac) or the
PC (PCMCIA) slots (on a PowerBook).  As I tried to sketch out, there
are several options.  An iMac has no extension slots, so as a "closed
box" we can rule it out.

Your remarks suggest the 4 projectors will need to fit inside the
cube, though perhaps cables might allow the Mac itself to remain
outside, and you note that money and space are both limiting factors.

Some video cards are available with two independent outputs; these are
referred to as "dualhead" video adapters.  The PCI adapters tend to be
less expensive than the PC/PCMCIA counterparts, so if there were
physical room for the desktop system, it might make more room in your

I'm not sure how much research you require for the list price offered,
but at least you've been able to refine your Question considerably
from its original statement.  The short answer is that with extra
video adapters installed and a suitable configuration of the attached
projectors as monitors in Control Panel, the applications should be
able run in parallel.

Of course you should be able to test this on a single monitor, running
as windowed applications.  There may be something in the application
code that prevents more than one instance; the software vendor would
be the expert on that, if the test fails for some reason.

Then I'd move to getting one extra video adapter and one projector and
testing them.  Note that the projector by default reverses left/right
orientation with respect to screen display, so that it "reads"
correctly on the wall.  In your case, however, this reversal is
unwanted because the display will be projected outward from the cube's
interior.  Your graphic application may be able to compensate for
this, or the projector model may have an option to override this

regards, mathtalk-ga
Subject: Re: How to run multiple instances of an application? On a Server?
From: jjpaul-ga on 14 Apr 2004 00:52 PDT
Ok the gist of your last answer, and I will start to
see if I can run 4 instances of the same program with my G3...
Since my real skills are in the audio field, one last clarification
needs to be will the apps know which card/output they need
to access?
Obviously these kind of apps are produced under the "one app, one
computer, one screen/output" assumption.
Even if I would install the add'l PCMCIA cards I would still need to
find a way to rout the signal to the appropriate buss (to paraphrase
what happens in the audio environment).
Or am I missing something here?
Subject: Re: How to run multiple instances of an application? On a Server?
From: mathtalk-ga on 14 Apr 2004 05:42 PDT
There is such a thing as a standard Mac user interface, and it
involves running things in "windows".  It is possible that someone
would write an application that does not conform to this standard, as
in fact Apple itself is occasionally guilty of.  But I'm unable to tie
out your description of the "UI Software" graphic applications.  I
don't know who this company might be or which program in particular
you are using.  But if there program doesn't run in a "window" (which
allows you to move it about), then I'd contact them for options to run
it when more than one display device is available.  For a bit of
insight into how the configuration might work, take a look at the
Control Panel applet for displays.  One option is to allow all the
displays to be coordinated as a "common" desktop, and for many users
this makes sense, as program windows can be "dragged" by the mouse
from one display to another (or even left overlapping more than one
display).  It's probably worth buying an extra $100 adapter just to
get a feel for this.  You might wind up using 1) the built-in display,
2) a single head video adapter, and 3) a dual-head video adapter to
reach the four required for your installation.

regards, mathtalk-ga

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