Question

I am planning to develop open source java application to work on google app engine as well as normal rdbms system, so please help me in choosing

MVC Framework –
Struts / Spring MVC ?

ORM –
JDO / JPA ?

I am considering performance as a key factor.

Answer 1

For app engine you will want a lightweight framework, both for persistance and application stuff. Google is changing their pricing model so you might want to consider how this will impact your plans as well. There is an interesting discussion on the app engine group about this: https://groups.google.com/forum/#!topic/google-appengine/ob-kMuDAAqc/discussion

Aside from that I can only comment on the choice of persistance framework:

JDO on app engine is a pain. The version they (Google) support in app engine is 1.x, which is ancient, I believe. I have had more trouble with getting things to work than I care to remember. If you have previous experience with JDO this still might be a good choice. If I were to start over again I would choose a persistence framework that was specifically written for app engine, like objectify or twig. They require less overhead and are easier to use (from my point of view). One giant plus of objectify: gives you memcache support out of the box with no extra work. How great is that?

However, you also want to support an RDBMS. If you have the time, you could roll your own abstraction layer on top of objectify and the RDBMS persistance layer of your choice. That would give you the edge in performance that you are looking for. 😉

If that is not an option I would suggest JPA (not because I have used it myself, but because I had so much trouble with JDO).

Hope this helps!