Speeding up Adaptation of Web Service Compositions Using Expiration Times
John Harney (LSDIS Lab, University of Georgia)
Prashant Doshi (University of Georgia)
Web processes must often operate in volatile environments where the parameters of the participating service providers change during the life cycle of the process. Optimally adapting to these changes, therefore, becomes an important challenge. Adaptation requires the knowledge from each of the service providers as to how much each of their service parameters have changed and using this knowledge to determine whether the Web process should make a different, and subsequently, more optimal decision. Monitoring this information change requires additional computations and may become a time-consuming process. In this paper, we use service expiration times obtained from pre-defined service level agreements to reduce the computational overhead of adaptation. We use the intuition that services whose parameters have not expired need not be considered for querying for revised information. Using two realistic scenarios, we illustrate our approach and demonstrate the associated computational savings.