José Luis Vázquez-Poletti

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Simulation techniques have become a powerful tool for deciding the best starting conditions on pay-as-you-go scenarios. This is the case of public cloud infrastructures, where a given number and type of virtual machines (in short VMs) are instantiated during a specified time, being this reflected in the final budget. With this in mind, this paper introduces(More)
Since the late 1990s, we have witnessed an extraordinary development of Grid technologies. Nowadays, different Grid infrastructures are being deployed within the context of growing national and transnational research projects. However, the coexistence of those different infrastructures opens an interesting debate about the coordinated harnessing of their(More)
In order to achieve a reasonable degree of performance and reliability , Metascheduling has been revealed as a key functionality of the grid middleware. The aim of this paper is to provide a comparative analysis between two major grid scheduling philosophies: a semi-centralized approach , represented by the EGEE Workload Management System, and a fully(More)
Despite the importance of providing fluid responsiveness to user requests for interactive services, such request processing is very resource expensive when dealing with large-scale input data. These often exceed the application owners' budget when services are deployed on a cloud, in which resources are charged in monetary terms. Providing approximate(More)
—Cloud computing, with its support for elastic resources that are available on an on-demand, pay-as-you-go basis, is an attractive platform for hosting Web-based services that have variable demand, yet consistent performance requirements. Effective service management is mandatory in order for services running in the cloud, which we call elastic services, to(More)
—Modern latency-critical online services often rely on composing results from a large number of server components. Hence the tail latency (e.g. the 99th percentile of response time), rather than the average, of these components determines the overall service performance. When hosted on a cloud environment, the components of a service typically co-locate(More)
The promise of "infinite" resources given by the cloud computing paradigm has led to recent interest in exploiting clouds for large-scale data-intensive computing. In this paper, we present a model to estimate the resource costs for executing data-intensive workloads in a public cloud. The cost model quantifies the cost-effectiveness of a resource(More)