International audienceCloud computing is nowadays one of the most promising IT technologies, since it provides seemingly unlimited resources on demand at low costs. Hence, different types of applications have been migrated to IaaS environments, e.g. multi-tier (distributed) applications. However, in order to benefit from such characteristics, cloud configurations (i.e. virtual resource configurations) should be designed accordingly to the necessities of the applications. Furthermore, such configurations have to provide the required resources not only at the application deployment-time, but also during the whole application execution time. Hence, adaptive paradigms are required when designing solutions to cloud applications with dynamic reso...