SpiderNet: A Quality-Aware Service Composition Middleware

Internet has evolved into an indispensable service delivery infrastructure. Various application services such as multimedia services and web services have been widely deployed and used. However, due to the problems pertaining to scalability, reliability, and manageability, traditional monolithic service provision approach has become inadequate. Thus, we propose a compositional approach for providing next-generation distributed application services. The compositional approach allows distributed application services to be automatically composed from atomic service components. Previous research work has addressed different problems in service composition, such as automatic function planning and load management. However, these existing solutions lack user desired scalability, flexibility and quality-of-service (QoS) support. Thus, the focus of this dissertation is to investigate a quality-aware service composition middleware framework, which can automatically compose services according to user's QoS requirements. The result of our research investigation is SpiderNet, a quality-aware service composition middleware framework. SpiderNet adopts a hybrid system architecture that consists of a core SpiderNet and multiple access SpiderNet subsystems. The core SpiderNet is deployed in wide-area networks, which is responsible for providing major service functions. The access SpiderNet is deployed at the network edge, which is responsible for ubiquitous service delivery. The major contributions of SpiderNet are as follows. First, we introduce a novel service overlay network model for constructing the core SpiderNet. Different from the conventional data overlay network, each node in the service overlay network provides not only application-level data routing but also various application services. The service overlay network connects previously dispersed service components via application-level connections to achieve high-quality and failure-resilient service composition. Second, we present two different designs for the core SpiderNet: utility SpiderNet and P2P SpiderNet, which are designed for managed enterprise systems and self-organized peer-to-peer systems, respectively. The utility SpiderNet employs global-state-based centralized approach for initial service composition and reactive failure recovery for maintaining the QoS of composed services during service runtime. In contrast, the P2P SpiderNet provides local-state-based fully distributed solution for initial service composition and proactive failure recovery for runtime service maintenance. Third, we present the access SpiderNet for ubiquitous service delivery. The access SpiderNet provides both service adaptation and service distribution to address the challenges of user mobility, device heterogeneity, and resource constraints in ubiquitous computing nvironments. We evaluate and validate the SpiderNet system both analytically and experimentally. We have conducted extensive experiments using both large-scale simulations and PlanetLab-based prototype implementation. We also implement a set of distributed multimedia services on top of SpiderNet as proof-of-concept application examples. Our experimental results demonstrate the implementation feasibility and performance efficiency of the SpiderNet system