Low installation costs, scalability and code re-usability makes Clusters and Grids more and more popular computing environments. Due to this phenomenon, the Application Service Provider concept, in which costumers pay for the use of software resources, is increasingly used. The AROMA (scAlable ResOurces Manager and wAtcher) resource management system developed during this thesis studies the main problematic of service providers systems: load monitoring, high availability, hardware and software dynamicity and identity based level of service. AROMA originality both resides in its ability to deal with dynamic aspects of clusters in one hand, and in the accuracy of the state information collected on cluster nodes on the other hand. This accurac...