eQoSystem: supporting fluid distributed service-oriented workflows

Many distributed applications have emerged asWebmashups [1], as well as loosely-coupled decentralized services predominant in a business ecosystem [3]. Many of these applications are implemented as service-oriented workflows and operated over cloud infrastructures. As a result, these applications demand agile development processes and low-touch maintenance life-cycles. Furthermore, in the cloud environment, application developers must account for the complex multi-tiered ecosystem that includes the services and resources they depend on, but which none of the developers have much control over. Therefore, it is essential for application developers to have tools that proactively adapt the application to the changes of the underlying ecosystem. We meet this need through eQoSystem, a framework that provides distributed workflow processing, declarative modeling of service-level agreements (SLAs), event-driven resource selection, and mobility of distributed tasks. In this demonstration, we focus on dynamically redeploying distributed workflows such that a whole or a part of the workflow is allocated to different execution engines that are possibly geographically dispersed. The redeployment of the workflow is enabled by a federated content-based publish/subscribe overlay that also serves as the basis for driving the autonomous and event-driven execution of workflows.