Java components with constraints and preferences in automatic administration of execution and placement

The cost and the reactivity constraints in software development imposed the components technologies as an alternative strategy to traditional software conception. This concept is vital in today´s technologies such as Java, DCOM or CORBA 3. One of the interests of these technologies is the ability for applications to use a supporting environment intrinsically distributed and based on. the Internet. However there are still some problems in order to be able to administrate components during their executions. Moreover at the beginning of its development, a component does not know the future hardware and software environment on which it will be executed. Consequently, it is necessary to provide a system support which will offer an adapted execution environment to these components where they can express their own constraints and preferences. In this article, we present some of our specifications for these new services in order to automatically administrate and manage the execution of the application and finally some results of our implementation.