RAC vs. J2EE

Background:
Our organization has a significant investment in application modules written in PL/SQL to support our e-commerce web site and catalog business. Such examples would be days to delivery on an order, P&H calculations, discounts/rewards for a customer order, SKU information, and line item tax calculations. Currently these applications are separately deployed in our e-commerce system and our internal phone order system. There is a desire to move some these type of programs toward a more service-oriented architecture under a single deployment. The issue that is trying to be addressed is whether these could be deployed only to a RAC cluster or should they be deployed on a J2EE middle tier running iAS backed by a RAC cluster. The applications running under the RAC-only option would be accessed either by remote procedure calls through database links or by a thin web services layer run out of the database.

The benefits and features of the J2EE architecture are known and well understood but would like some guidance as to if some of these features could/should be provided by deploying the applications on RAC instead.

The rationale is as follows:
**the primary objectives of this architecture are availability,
  manageability, and scalability.
**PL/SQL, not Java, is the core strength of our developers.
**The database tier, not the J2EE middleware tier, is the core
  strength of our DBAs.
**A large repository of PL/SQL code exists within our organization.
**The DBA group has 1 year of experience managing a RAC environment.
**Features offered by iAS in this deployment such as wireless, B2B,
  Oracle Portal, Web Cache, Sensors, BPEL, and etc are not   anticipated to be needed.

Questions:
1. Given the needs and objectives outlined, would running these applications only out of a RAC environment be a practical approach? If not, then why not?
2. In terms of AMS (availability, manageability, and scalability), performance, and costs, does a J2EE architecture have any significant advantages over a RAC architecture?
3. For future development efforts, are there recommendations as to when an application should be run in a J2EE middle tier vs. in the database (PL/SQL)? Received on Tue Feb 15 2005 - 09:46:56 CST