Edmundo Roberto Mauro Madeira

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Workflows have been used to represent a variety of applications involving high processing and storage demands. As a solution to supply this necessity, the cloud computing paradigm has emerged as an on-demand resources provider. While public clouds charge users in a per-use basis, private clouds are owned by users and can be utilized with no charge. When a(More)
Among the numerous DAG scheduling heuristics suitable for heterogeneous systems, the Heterogeneous Earliest Finish Time (HEFT) heuristic is known to give good results in short time. In this paper, we propose an improvement of HEFT, where the locally optimal decisions made by the heuristic do not rely on estimates of a single task only, but also look ahead(More)
Cloud computing is being used to avoid maintenance costs and upfront investment, while providing elasticity to the available computational power in a pay-per-use basis. Customers can make use of the cloud as a software (SaaS), platform (PaaS), or infrastructure (IaaS) provider. When one customer utilizes an environment provided by a SaaS cloud, she is(More)
This paper presents a virtual machine scheduling algorithm for Cloud Computing based on Green Computing concepts. The goal of this algorithm is the minimization of energy consumption in task executions in a cloud computing environment. This algorithm uses some features like shutdown of underutilized hosts, migration of loads of hosts that are operating(More)
Schedulers for cloud computing determine on which processing resource jobs of a workflow should be allocated. In hybrid clouds, jobs can be allocated either on a private cloud or on a public cloud on a pay per use basis. The capacity of the communication channels connecting these two types of resources impact the makespan and the cost of workflows(More)
The workflow paradigm has become the standard to represent processes and their execution flows. With the evolution of e-Science, workflows are becoming larger and more computational demanding. Such e-Science necessities match with what computational Grids have to offer. Grids are shared distributed platforms which will eventually receive multiple(More)
The Internet has become the universal support for computer applications. This increases the need for solutions that provide dependability and QoS for web applications. The replication of web servers on geographically distributed data centers allows the service provider to tolerate disastrous failures and to improve the response times perceived by clients. A(More)
Cloud computing systems provide on demand access to computational resources for dedicated use. Grid computing allows users to share heterogeneous resources from multiple administrative domains applied to common tasks. In this paper we discuss the characteristics and requirements of a hybrid system composed of both grid and cloud technologies. We propose an(More)