RE: RPG vs. Java vs. C++ -- RPG400-L

Hi All,

I would like to thank everyone who offered a comment on my question
posed to the group on language comparisons.  I now have a lot of
comments and suggestions I can bring back to senior management.

Maybe we'll even get a new iSeries (i5!) out of it too! :)

Thanks again!

Brian.

-----Original Message-----
From: Reeve [mailto:rfritchman@xxxxxxxxx] 
Sent: Friday, March 25, 2005 10:09 PM
To: RPG programming on the AS400 / iSeries
Subject: Re: RPG vs. Java vs. C++

t always helps to give a simple and straightforward answer to the
Suits' questions.  This is a business question, not a technical
question; give them an honest answer in language they'll understand.

The answer might go something like this:
"Programs written in C++ might go faster because they might execute
fewer computer instructions; it depends upon the programmer.  But C++
is manily an "operating system" programming language, not a "business"
programming.  It's not generally used for business programming, it's
harder to master than RPG, and every RPG program will be to be
re-written.  Because of the certain cost of rewriting many RPG
programs and the uncertain performance benefit, this is not likely to
be a prudent or cost-effective decision.  But if we can identify one
specific program using an inordinate amount of CPU power, we should
review that program and determine the cost of rewriting it in RPG or
C++ is less expensive that other options.

"Java is almost certainly not the right approach.  Java is an
"interpreted" language, not a "compiled" language.  "Compiled"
languages like RPG "touch" the computer hardware directly;
"interpreted" languages have to work through another program (the
"Java Virtual Machine") to touch the hardware.  Therefore, the number
of instructions executed will be much larger for a Java program than
for either an RPG or C++ program and this means a Java program will
run slower.  Java's benefit is that it runs on a wide variety of
hardware platforms but it takes considerably more system resources to
support this capability.

"I recommend bringing in a consultant for two days to review system
configuration and performance.    A qualified performance expert will
tell us how to get more performance out of the system, if it's
possible, and may be able to identify the program(s) causing the
performance bottleneck.  This is the least expensive option and will
dictate if other options (rewriting one or two programs or upgrading
the hardware) are appropriate and cost-effective.

-reeve




On Thu, 24 Mar 2005 15:56:11 -0500, Brian Piotrowski
<bpiotrowski@xxxxxxxxxxxxxxx> wrote:
> Hi All,
> 
> I know this is off-topic, but I'd like to get everyone's thoughts on
> this subject.
> 
> If this has been discussed ad-nauseum, I apologize in advance.
> 
> Management has asked if there would be any value to having additional
> applications on our iSeries that were not designed in RPG.  Rather,
they
> asked the impact that using Java or C++ based applications would have
on
> the server.
> 
> Does anyone have any data or performance metrics (or better yet,
links!)
> they could share to give me an idea on how a Java app would perform on
> an AS/400 vs. a C++ app. Vs. an RPG app?
> 
> The reason management has been asking is due to the legacy programs
that
> run on our machine.  We are currently running a 720 series w/2GB main
> storage and 175GB raid 5 array with 90% of the programs written
in-house
> (and before my time).  At any given time, when I look at the
performance
> of our AS/400 (through system status), and it always seems to be above
> 65% (or it's often at ++++ when I look at it).
> 
> Management wonders if these programs were rewritten in C++ or Java if
it
> would have a positive effect on the server?
> 
> Any comments are welcomed and appreciated.
> 
> Thanks,
> 
> Brian.
> 
> -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> 
> Brian Piotrowski
> 
> ISD Specialist
> 
> Simcoe Parts Service, Inc.
> 
> 6795 Industrial Parkway
> 
> Alliston, ON, L9R1W1
> 
> bpiotrowski@xxxxxxxxxxxxxxx
> 
> ph: 705-435-7814 x343
> 
> fx: 705-435-6746
> 
> -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> 
> --
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