The impact of IT on the global energy consumption has frighteningly increased over the last years. One of the reasons for this is the demand for infrastructure to support the increasing number of online (24x7) services and data, followed by the popularisation of practices like Cloud Computing. From the infrastructure point of view, hardware throttling and server consolidation are techniques used to deal with energy efficiency. However, details about the application behavior are not visible from the infrastructure layer, which prevents a more complete energy-efficient treatment. This paper presents an approach for self-optimisation of the energy consumption at the application layer. We rely on Service-Oriented Architectures, since they allow rapid and seamless service composition and eases the application adaptation. The energy efficiency properties of services are defined by means of Quality of Service criteria and a set of event-condition-actions is defined to enable the application to react to environmental changes and optimise its energy consumption. As a proof of concept, we present a prototype for energy-aware self-adaptation in SOA-based applications as well as an example scenario that shows the practical usage of our approach.

Web services are becoming de facto a standard for data exchanging, since they provide a clear way to express and access information throughout the Internet. Sometimes, one service alone is not able to perform a certain task, and it might be necessary to compose two or more services in order to accomplish that task. In this context, semantic web services play an essential role, since they provide a framework to formally describe services in a way that it is possible to machines to automatically discovery, compose, invoke, and monitor them. On the other hand, only functionality is not enough to fulfill users' satisfaction, in the sense that service providers should guarantee the quality delivered by their services. In this paper, we present a heuristicbased approach for automatic semantic web services composition. Besides considering the functional correctness, the proposed heuristics also takes into account the overall quality of the composite service during the composition process.

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Web services are becoming de facto a standard for data exchanging, since they provide a clear way to express and access information throughout the Internet. Sometimes, one service alone is not able to perform a certain task, and it might be necessary to compose two or more services in order to accomplish that task. In this context, semantic web services play an essential role, since they provide a framework to formally describe services in a way that it is possible to machines to automatically discover, compose, invoke, and monitor them. On the other hand, only functionality is not enough to fulfill users' satisfaction, in the sense that service providers should guarantee the quality delivered by their services. In this paper, we present an infrastructure for dynamic web service composition. The main element of the infrastructure is the composition mechanism which is based on quality of service. Experimental results indicates the proposal soundness.