Decision Support System for Migrating Legacy Applications to the Cloud: Improving System Availability and Protecting Against Disasters

Using cloud computing helps enterprises to reduce their operational costs as well as to improve the scalability, availability, and reliability of their services. To improve system availability and protecting against disasters, enterprises have to decide how to migrate their on-premise applications to the cloud. Migrating of a legacy application to the cloud is a very complicated and time-consuming process, due to the complexity of applications, the dynamic environment of the enterprises and the variety of available cloud services. Despite many types of research in this context, a formal migration model based on known patterns has not been presented yet.  In this paper, the Finite State Process (FSP) algebra is applied as a formal basis by which a step by step migration support system can be built automatically from the known application and cloud profiles. The proposed step by step migration model is superior to the current optimization methods that search the optimal deployment of application components to cloud services due to the fact that a step by step approach is more appropriate for dynamic environments. In fact, the main advantage of this method over previous methods is that it supports the automation of the migration plan with the possibility of modifying the migration path based on changing objectives in dynamic enterprise environments.