An Application-Level Service Control Mechanism for QoS-Based Grid Scheduling

In market-based service-oriented grids, scheduling service execution should account both for user- and provider-dependent Quality-of-Service (QoS) requirements. In this scenario we propose a mechanism to allow for flexible provision of grid services, i.e. to allow providers to dynamically adapt the execution of services according to both the changing conditions of the environment where they operate in, and the requirements of service users. The mechanism is based on handling program continuations for providing application-level primitives to control suspension and resuming of service execution at run-time. These primitives can also be accessed by consumer programs as web services. This approach makes the proposed control mechanism a basic programming layer to build a flexible and easily programmable middleware to experiment with different scheduling policies in service-oriented scenarios.