With the increasing demand in application adaptability and the current availability of open libraries, delegating concerns in external frameworks becomes a more and more common software engineering practice. A consequence of this evolution is that the way frameworks are connected becomes an important issue for modularity, maintainability and extensibility.

We study in this paper the framework connections involved in a typical middleware application using our load balancing service called DLBS. Such application consists in three frameworks: the client application, the middleware and DLBS.

DLBS (Dynamic Load Balancing Service) brings new solutions regarding large scale load balancing for middleware based applications. DLBS offers a portable, multi-criteria and customizable load balancing service. It consists of a scalable monitoring infrastructure, a connection manager and customizable load balancing strategies. DLBS portability and integration across several middleware is made using aspect oriented techniques.