You don't need to have a central dedicated server with my method but you
could have as many servers as you like.
You also don't need Midas. Checkout Midware (www.thensle.de (?)). It's
free, open and it works. It will do all the TCP/IP sockets stuff invisibly
and it has a TDataset descendant. The backend db can be anything.
You also don't need MS/IBM MQ, I was just mentioning this as the only 100%
(?) gaurenteed delivery mechanism.
Having done some OB work in my youth I can understand your space constraints
and the need for robustness. However, there is no quick solution to your
problem and if you need something that is both quick and reliable then it's
going to take a bit of work.
I agree with Nic that it would be best to have something that doesn't
crash... but, given your environment it's probably more likely that it will
crash more often than most systems. So I thinks it's better to go for some
redundancy and a system that will recover fast. For specific tools I would
use:
1: Delphi 4/5 thin clients.
2: Midware (free) or Midas (expensive) middleware.
3: Interbase 5.6 or 6 (maybe MySQL or BDE) on multiple 'servers'.
Given the limitations of the Local IB license you would need to purchase
real IB for at least 2 'servers' with licenses for all users X 2. If you
went with MySQL or BDE then it's free but not as robust or quick to recover.
Midware lets you create threaded server objects very easily, provided you
keep the BDE away from it (use IBObjects or FreeIB or IBExpress). So it
will hide the socket and threading stuff for you and make the job a lot
easier.
That's enough free advice! Want to hire me yet?
>Hmmmm...... Yes some good thoughts in there. But..... There always is......
>
>- I agree that a broadcast socket type solution is just "too hard".....
>
>I kind of like your idea of central server and messages however.....
>
>- My environment does not allow me to put down "servers" to do just DB
>work.
>We have limited space (Our stuff typically lives in a TV truck. To
>understand the space constraint. Put 5 towers on your desk together with
>mice, KB's, monitors etc. and then sit 5 people in front of it. That should
>give you some idea.... *grin*) and as such each machine performs a
>function
>and where necessary doubles as a "server". Because each machine has real
>time functions to perform, server processes must not be too possessive in
>terms of resources. Also the boxes are NT WKS and I am not sure that MSMQ
>will run on that.
>
>- Also when sending a "GET" message, I would still like that to be a SQL
>request so that I can get data into say a TQuery so that I can still use
>the
>functionality of DB Aware controls and the BDE/ADO/IBX etc. Not sure how I
>would handle. Workstation1: "I need some data server1" Server1: "Wait. Let
>me check that I have the latest data" Server1 "Hey Workstation 1 you can
>get
>your data" Workstation1 executes SQL or whatever......
>
> > Using this mechanism you can have as many servers as you like.
>
>Sounds a bit like MIDAS, nTier to me..... Trying to stay away from that if
>I
>can.....
>
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