[comp.sys.mac.programmer] Protecting apps on networks

francis@csli.Stanford.EDU (Dave Francis) (08/31/90)

Hello!

I need information about how to protect my application from being run
multiple times on a network. The behavior I'm looking for is seen
in 4th dimension where you can't run more than one application at
a time on the network unless you buy more than one. Do I need to know
a lot about AppleTalk to implement this??

Thanks for any help,
Dave Francis - Sapphire Design Systems

Jim.Matthews@dartmouth.edu (Jim Matthews) (08/31/90)

In article <15105@csli.Stanford.EDU>, francis@csli.Stanford.EDU (Dave Francis)
writes:
> I need information about how to protect my application from being run
> multiple times on a network. The behavior I'm looking for is seen
> in 4th dimension where you can't run more than one application at
> a time on the network unless you buy more than one.

The behavior exhibited by 4th Dimension isn't something that any network
administrator is looking for -- 4D floods every zone of an AppleTalk internet
with broadcast packets, which translates to bothering 6,000 computers on
a network like ours.  If you want to be sure that only one copy of a program 
is running on an internet you should think about having a central server 
that the application registers with.  In fact, such a system (called the
KeyServer) is available from Sassafras Software (603-643-3351, or 
denisd@dartmouth.edu for e-mail).  I believe that the University of Michigan 
has a similar system called LaunchBreak.

Jim Matthews
Dartmouth Software Development

Disclaimer: The developer of the KeyServer is a colleague of mine.
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