Evolution pattern for Service Evolution in Clouds

The proposed research will focus on developing a novel approach to solve Software Service Evolution problems in Computing Clouds. The approach will support dynamic evolution of the software service in clouds via a set of discovered evolution patterns. An initial survey informed us that such an approach does not exist yet and is in urgent need. Pattern will be categorised into five groups in order to solve different kinds of evolution problems, such as SaaS dependency dealing, SaaS structure transformation, SaaS evolvability enhancement, SaaS system dynamic enhancement and SaaS function enhancement. It contains dynamic process and static details. Evolution mechanism will be used for driven the evolution pattern into execution; both mechanism and pattern are corresponded with each other. After the pattern design is finished, the whole approach will have these contributions: 1) the synergistic pattern-driven framework for cloud service evolution; 2) a repository of evolution patters for cloud services (mainly for SaaS); 3) the formal specification of the evolution patterns; 4) the mechanism to apply the patterns to cloud service evolution at run time: driving the evolution, monitoring the process, and verifying the correctness; 5) the resultant prototype tool. Both dynamic and static description of the evolution pattern has been given in the paper.