Learn More
The overall increase in traffic on the World Wide Web is augmenting user-perceived response times from popular Web sites, especially in conjunction with special events. System platforms that do not replicate information content cannot provide the needed scalability to handle large traffic volumes and to match rapid and dramatic changes in the number of(More)
In the service oriented paradigm applications are created as a composition of independently developed Web services. Since the same service may be offered by different providers with different non-functional Quality of Service (QoS) attributes, a selection process is needed to identify the constituent services for a given composite service that best meet the(More)
✦ Abstract—Architecting software systems according to the service-oriented paradigm, and designing runtime self-adaptable systems are two relevant research areas in today's software engineering. In this paper we address issues that lie at the intersection of these two important fields. First, we present a characterization of the problem space of(More)
Runtime adaptation is recognized as a viable way for a service-oriented system to meet QoS requirements in its volatile operating environment. In this paper we propose a methodology to drive the adaptation of such a system, that integrates within a unified framework different adaptation mechanisms, to achieve a greater flexibility in facing different(More)
Today Critical Systems are even more complex and interdependent. Example of Critical Systems are telecommu-nication, public transportation, industrial plant and process control, command and control, surveillance, air traffic control , avionics, e-government systems, emergency management systems. When the disruption of a critical system can seriously affect(More)
Grid computing is the future computing paradigm for enterprise applications. An enterprise application running on a grid is composed of a set of SLA-constrained sub-tasks demanding different types of services and resources such as processors, data storages, service providers, and network links. This paper formalizes the resource allocation problem for(More)
Grid computing promises to become the future computing paradigm for enterprise application after having shown to be a quite effective computing paradigm for resource-intensive scientific applications. Large scale grids are complex systems, composed of a large number of components belonging to disjoint domains. Planning the capacity to guarantee quality of(More)