From: Peter Dow (ML)
I've been reading this thread and I'd be interested in hearing where
*you* think CC should be used. You say you've used it, but all of your
posts are explaining why other peoples' scenarios are not justified in
using CC. Please tell us why you used it and what your justification
was (inquiring minds want to know :-) ).
First, I hope you're not somehow offended by the fact that I presented my
opinion (people do hate it when I question the common beliefs). I have a
real problem with over-engineered software. A perfect example is EJBs, a
solution without a problem which is only just now being slimmed down to
where it's usable. And if you re-read the thread, you'll see that I was
okay with using commitment control in the banking application.
As to where I've used commitment control, my primary experience has been in
two places. My first was in a client site where we attempted to CC all of
BPCS back in the early 90s. This is where I learned that if you don't
design the application for CC up front, engineering it in after the fact is
almost impossible. Just trying to identify the transaction boundaries was
nearly impossible.
The other application was for a client/server order entry system. The PC
would collect orders based on a local copy of the database while
disconnected, then attempt to upload the orders on connect. Commitment
control provided an easy way to avoid database corruption if the line failed
(or any of the other myriad problems that occur in distributed processing).
We could have done it without CC, but we would essentially have had to write
our own. We did find that there were lock conflicts with slow communication
lines - if two people try to upload orders that happen to contain the same
item and the transaction locks the item master, then you have a problem,
especially if the upload process is on an extremely slow connection.
I have no problem using technology correctly, I just have a problem when
people say that some favorite technique is always "better". Just like
deciding to use object oriented design or extreme programming - it's always,
always a business decision.
Joe
midrange.com
