Contents | Previous | Next |
Evolution in open distributed systems must be managed carefully because correct operation depends on a great number of dependencies between packages. The impact of changes within a distributed system has a significant impact on users, support organizations, web administrators, and developers. Packages within a distributed system must operate correctly given only partial knowledge about the state of the whole system. The difficulty is increased because the packages of the system must be able to evolve at different rates. Evolution in such a system is made possible by explicitly managing the dependencies between the packages using techniques of object oriented design to govern how individual packages evolve. The Java language defines packages that are a natural for the consistent unit of update, they expose only public interfaces and consume only public interfaces of other classes.
Contents | Previous | Next |