RE: Java Apps on iSeries-Performance

["Joe Pluta" <joepluta@xxxxxxxxxxxxxxxxx>]

What CPW is your machine, John?  How much memory?  What version of OS/400?
What does your application do?

I have a tiny little model 270 (370CPW) and I run servlets with no problems
whatsoever.  My little model 520 does even better.  I get subsecond response
time, but that's because I have a very thin JSP front end to an RPG business
logic back end.

If, however, this is a 100% Pure Java application using JDBC for database
access, then you're probably going to need more horsepower.  JDBC is a Java
wrapper over ODBC and is simply horrible for OLTP applications.  This is
especially true if the application is written using EJBs.

If Java isn't written from the ground up for performance (for example, it
was designed originally to run on a dedicated Wintel box with a fast CPU and
lots of memory) then it will definitely suffer when you try to run it on a
mixed-load business server like the iSeries.

Joe

> From: John Walsh
> 
> Our application provider is developing an enhancement to the existing
> app and it is developed in java.  Apprarently, our model 800 will not be
> able to support this satisfactorily in terms of performance.
> 
> Can someone point me to some documentation that addresses needing a
> bigger, better, faster box to run java apps.  I need to write a report
> on this issue.  Thanks.