Performance Annotations for Cloud Computing.

Web services and applications are complex systems. Layers of abstraction and virtualization allow flexible and scalable deployment. But they also introduce complications if one wants predictable performance and easy trouble-shooting. We propose to support the designers, testers, and maintainers of such systems by annotating system components with performance models. Our goal is to formulate annotations that can be used as oracles in performance testing, that can provide valuable guidance for debugging, and that can also inform designers by predicting the performance profile of an assembly of annotated components. We present an initial formulation of such annotations together with their concrete derivation from the execution of a complex web service.