On 5 Dec 2001, at 19:55, guido.klapperich@... wrote:

> I'm thinking about a licence-mechanism for my app. I want to licence
> the number of simultaneous connections, for example you have a
> 5-User-Licence, then 5 users can work simultaneous on the db. The
> problem is, when the pc of a user crashes, then he is marked in the db
> as logged in, but he isn't. Therefore the client tells every 10
> minutes the server I'm alive and when the client crashes, the server
> recognizes after 10 minutes, the client is dead and marks the user as
> logged out. But therefore I need a task, that checks all 10 minutes,
> if the user is alive. How can I realize this with IB ?
>

Here is a way,
When the application runs, it does a count on a heart-beat table,
if the count is less then the licence count, then it adds a record,
giving a userid or machineid for the key, every 5 minutes each
machine updates it's heart-beat, a trigger at that point does two
things, it updates a Timestamp field to show the current Date/Time,
then deletes any record more then 10 minutes old.

When the program is ended properly, it deletes it's heart-beat
record.

Paul
Paul Schmidt
Tricat Technologies
paul@...
www.tricattechnologies.com