Estimando o valor de uma grade P2P usando provedores de infraestrutura como serviço como parâmetro de comparação.

Abstract

Desktop grids have been used as a low cost solution to run Bag-of-Tasks (BoT) e-science applications for at least the last fifteen years. Despite their best-effort characteristic, the appealing low cost of deploying and operating desktop grids make them a good fit for the execution of such embarrassingly parallel applications. Recently, the cloud computing paradigm, by means of Infrastructure as a Service (IaaS), has emerged as an alternative to run these kinds of applications, offering more control on the quality of service delivered, without requiring too large expenditures. Until now, it was not easy to assess the value that a desktop grid can bring to users of BoT applications using business-oriented metrics. Here, we try to shed some light on this issue by using a cloud computing platform as a cost reference. In this work, we compare the performance yielded by both types of infrastructure for the execution of typical e-science BoT applications. Afterward, we analyse the trade-off performance/cost resulting from the executions on the different options in the cloud in order to identify the representative options. Then their execution costs are used to estimate the value that a desktop grid can bring to its users of BoT applications. We also consider the extra costs incurred by the peers in donating its idle resources to the grid aiming to verify its effectiveness as a low cost solution even before the omnipresent cloud computing paradigm. Our simulation results corroborate the effectiveness of the grid as a low cost solution. Due to scalability limitations from the current IaaS providers, considering the cost-benefit relation, desktop grids manage to achieve a competitive valuation even before the best option currently offered by the cloud. To users whose the main concern is the cost, even in scenarios with just a few peers, the grid outperforms the cloud. On the other hand, to small grids and users whose main concern is the performance, the grid isn’t a so effective solution and the cloud stands out as the best option.