The design and implementation of service process reconfiguration with end-to-end QoS constraints in SOA

Service processes in SOA are composed dynamically by services from different service providers. At run-time, some services may become faulty and cause a service process to violate its end-to-end quality of service (QoS) constraints. We propose an effective approach for replacing only faulty services and some of their neighboring services to maintain the original end-to-end QoS constraints. We use an iterative algorithm to search for a reconfiguration region that has replaceable services to meet the original QoS constraint for the region. Services in reconfiguration regions may be replaced using one-to-one, one-to-many, or many-to-one service mappings. By replacing only services in reconfiguration regions rather than the whole service process, reconfiguration overheads are lowered and service disruptions may be reduced. We have implemented the Adaptation Manager in the Llama ESB middleware. Performance study shows that our approach may efficiently repair service processes.