A Framework Enabling the Cross-Platform Development of Service-based Cloud Applications

Among all the different kinds of service offering available in the cloud, ranging from compute, storage and networking infrastructure to integrated platforms and software services, one of the more interesting is the cloud application platform, a kind of platform as a service (PaaS) which integrates cloud applications with a collection of platform basic services. This kind of platform is neither so open that it requires every application to be developed from scratch, nor so closed that it only offers services from a pre-designed toolbox. Instead, it supports the creation of novel service-based applications, consisting of micro-services supplied by multiple third-party providers. Software service development at this granularity has the greatest prospect for bringing about the future software service ecosystem envisaged for the cloud. Cloud application developers face several challenges when seeking to integrate the different micro-service offerings from third-party providers. There are many alternative offerings for each kind of service, such as mail, payment or image processing services, and each assumes a slightly different business model. We characterise these differences in terms of (i) workflow, (ii) exposed APIs and (iii) configuration settings. Furthermore, developers need to access the platform basic services in a consistent way. To address this, we present a novel design methodology for creating service-based applications. The methodology is exemplified in a Java framework, which (i) integrates platform basic services in a seamless way and (ii) alleviates the heterogeneity of third-party services. The benefit is that designers of complete service-based applications are no longer locked into the vendor-specific vagaries of third-party micro-services and may design applications in a vendor-agnostic way, leaving open the possibility of future micro-service substitution. The framework architecture is presented in three phases. The first describes the abstraction of platform basic services and third-party micro-service workflows,. The second describes the method for extending the framework for each alternative micro-service implementation, with examples. The third describes how the framework executes each workflow and generates suitable client adaptors for the web APIs of each micro-service

On the Role of Ontologies in the Design of Service Based Cloud Applications

The wide exploitation of cloud resources has been hindered by the diversity on the provision of these resources and thus resulting in heterogeneity between them. Research efforts on the design of cloud applications, leveraging resources form heterogeneous cloud environments, have been concentrated on traditional cloud platform resources such as deployment capabilities and data stores. However, the emergence of the cloud application platforms has made available a wide range of platform basic services (e.g. e-mail, message queue and authentication service) that can drastically decrease the application development time. Our work focuses on eliminating the heterogeneity among the providers offering those services. To this end we propose an ontology-driven framework, which facilitates the seamless and transparent use of platform basic services provisioned by multiple clouds environments. Ontologies are leveraged to enable the homogeneous description of the functionality of the service providers