Distribution and object granularities

Objects are widely used to build distributed applications, since they provide a clean interface which may be used in handling remote communications between a client and a server. However there is still an open issue whether large objects and small objects should be handled in the same way from both the language and system points of view. The most widely supported view is the client/server model in which large objects (usually the remote server objects) are distinguished from small local objects used inside a server object. In this approach distribution is associated only to server objects bet not to local objects We believe that there actually exist at least two granularities of objects, but they should not be differentiated by the distribution property. Programming in the small and programming in the large are well known in centralized programming models, and define fine-grained passive entities to build and structure coarse-grained active applications. Distribution is an orthogonal property which may be applied to both types of objects. This results in defining fine-grained passive objects, which may be distributed as in the blackboard approach, used to build coarse-grained active objects or servers, which in turn may communicate using the client/server model