Al-1/d: a distributed programming system with multi-model reflection framework

We have proposed the Multi-Model Re ection Framework [3] where an object is described by multiple models each of which abstracts the object behavior in the di erent level, i.e., from the operating system level to a high-level programming language level. In one model, some objects called meta-level objects are constituted to describe the behavior of an object called a base-level object. An object is causally connected with its multiple meta-level objects, so that the object may have the ability to modify its behavior by the modi cation of those meta-level objects. In this paper, the application of Multi-Model Re ection Framework to a distributed system is reported. In a traditional distributed system, the operating system (or the runtime library) supports for the network transparency. By the network transparency, we mean that the user do not need to take the nature of the distributed environment into account. In the distributed system, the system needs to automatically change the con guration to balance the CPU's and communication load and make the system reliable. If the functionality of the dynamic con guration is effectively operated, users are satis ed with the system. However, most cases fail because it is di cult for the operating system to recognize the application's behavior without any hints. Rather, some users know the application's behavior. They are willing to change the con guration of the distributed environment in order to run their applications e ciently. The requirement of the network trans-