Abstract
One of the main advantages of the cloud computing paradigm is that it simplifies the time-consuming processes of hardware provisioning, hardware procurement and software deployment. Currently, we are witnessing a proliferation in the number of cloud-hosted applications. However, one of the important challenges of the cloud computing paradigm that may hurt the growth of this technology is the interoperability and portability between cloud platforms. The developers and cloud users may lock-in to the first cloud they choose, or face difficulties when they have to move their data or software from one cloud platform to another. In this paper, we focus on the challenge of data portability between different cloud-based data storage services. In particular, we propose a common data model and a standardized API for the new generation of cloud-based NoSQL databases. The initial implementation of our framework covers three of the most popular NoSQL systems, namely, Google Datastore, Amazon SimpleDB and MongoDB. However, our framework is designed in a flexible way that it can be easily extended to support other NoSQL systems. Furthermore, our framework is equipped with tools that support the conversion, transformation and exchange of the data which is stored on the supported NoSQL databases of the framework. Finally, we describe the design and the proof-of-concept implementation of our framework using a case study.