Authors: Alexander Lenk, Jens Nimis, Thomas Sandholm, Stefan Tai
Web-based service delivery and billing by consumption are two defining properties of Cloud Computing. They leverage novel business models and sales channels for yet to develop as well as pre-existing applications. Many pre-existing applications are already capable of running in distributed environments, but still do not meet the requirements to run as a Cloud offering. For example, applications built to run in cluster environments are designed for distribution and massive scalability and from an architectural point of view qualify to be suitable for Cloud environments as well. However, a limitation of cluster-based applications with respect to Cloud adoption is that many of them initially do not support necessary Cloud service features such as payment services or multi-tenancy. To close this gap, we propose an open framework that helps to adapt pre-existing applications into commercial Cloud offerings. The framework facilitates the process to extend pre-existing applications with the respective required web service interfaces, which ultimately allows them to be consumed as Cloud offerings in a pay-as-you-go manner. The framework approach is illustrated by the transformation of the two well-known cluster applications Hadoop MapReduce and MySQL into full-blown Cloud offerings.