Reliable consumption of web services in a mobile-cloud ecosystem using REST

The evolution of the mobile landscape coupled with the ubiquitous nature of the Internet and the cloud is facilitating the deployment of enterprise and personalized mobile applications. In this research, we proposed a proxyenabled unification framework that integrates heterogeneous devices with multiple SaaS and IaaS cloud layers in order to support personalized and group file sharing. However, our proposed mobile-cloud ecosystem calls for open research questions which must be answered such as i) how do we synchronize the data across the consumer devices and the multi-IaaS backend?, ii) how do we authenticate the system users?, and iii) how do we push updates in a low-latency fashion? This paper addresses the three questions by proposing the adoption of the REST Web Service as an efficient way to consume the data on the mobile devices. However, we have to deal with the "CAP Theorem" which states that we can only achieve at most two properties at a time out of the following three: data consistency, system/data availability, and partition tolerance. Since partition tolerance is a given in a distributed system, we opt for the availability option by allowing file storage on the consumer devices in both online and offline modes. Further, we propose data consistency within a session that enforces update propagation in a soft-real time. The architecture is evaluated based on latency and scalability using multi consumer devices and employed Dropbox and Amazon S3 as the IaaS cloud providers.