RE: EJB versus RPG/COBOL

["David Morris" <David.Morris@xxxxxxxxxxxxx>]

Joe,

These are transaction programs -- from my message "This load allows a
weeks worth of transactions to be put through in 30 minutes." About
15,000 loads containing about 100,000 individual products were processed
against 500 checks being process, matched, sent to A/R and G/L in this
test. On our old 730, the RPG version of these applications had that
server pegged at 90% plus utilization. Throughput was poor due to the
volume of transactions. On this 825, the RPG based code only hits about
30% CPU utilization. My testing shows that this Java workload will push
that up to about 35% CPU utilization -- more memory would increase this
number. Since this was a load test, I kept pushing up the user counts to
see where the ceiling was and it comes in at about 40-50 simultaneous
users continuously hitting the submit button.

David Morris


>>> joepluta@xxxxxxxxxxxxxxxxx 3/12/2004 9:16:00 AM >>>
> From: David Morris
> 
> I spent this week load testing performance of a large scale
java-based
> system running on the iSeries.

David, I'm not saying your application doesn't perform well.  However,
you're not really providing any equivalence figures.  How many green
screen users can you get going?  Do they see the same degradation when
you have 25 users? Or 50?  You need to compare apples to apples to get
meaningful numbers.

Also, there is a difference between inquiries and transaction
processing.  SQL-based inquiries, especially the larger they get, blur
the distinction between Java and RPG because both end up spending most
of their time in the SQL engine.  I've always said that for pure
inquiries (especially ad hoc), SQL performs quite impressively, and
that
savings is then passed on to whatever your application is.

But for real transactions, where processing is done on individual
records and rules are based on database flags, RPG outperforms Java by
the 10-100 times figure I specified.

Joe