Re: Scalability Vs Performance in J2EE implementation

I am investigating the scalability of our product that deals to
retrieve 45000 rows for each client. Max number of client is 5.

I decided to migrate the Java code to J2EE code so that we can achieve
much scalability for the above mentioned scenario.

My superiors concern was scalability can be achieved but at the same
time, performance will be major hit as there will be lot of lookups
will happen between the client code to server, ejb to db and so on for
other j2ee components. And also, J2EE is used to ease the work of the
developers to develop the large scale applications.

My Question is How can i calculate the performance of the mentioned
scenario..is there any kind of formula or design pattern rules are
there to estimate the performance so that i propose the performance
report before i start implementation of the actual application

Thanks in advance for your valuable suggestions