I have an application that currently uses OSiV - and works brilliantly. I now am going to "upgrade" this application from 5 users to potentially 1000+ users.

2 questions:

1) At what point do you say I need to go n-tier and forget the OSiV pattern?

2) Currently my app has one MS server machine running Tomcat & MS Sql Server. If I seperate these into seperate machines, this won't hender OSiV will it? If not, why is OSiV so "unscalable"?

My "expert" who is going to code the upgrade insists I do away with OSiV, but I know this conversion will take a painful amount of recoding.

Any suggestions or experience in the matter?

Many thanks!