Web services QoS: external SLAs and internal policies or: how do we deliver what we promise?

With Web services starting to be deployed within organizations and being offered as paid services across organizational boundaries, quality of service (QoS) has become one of the key issues to be addressed by providers and clients. While methods to describe and advertise QoS properties have been developed, the main outstanding issue remains how to implement a service that lives up to promised QoS properties. This keynote speech revisits the current state of the art of QoS management applied today to Web services and raises a set of research issues that originate in the virtualization aspect of services and are specific to QoS management in a services environment – beyond what is addressed so far by work in the areas of distributed systems and performance management.