MACIEL JÚNIOR, P. D.; http://lattes.cnpq.br/1101383196957378; MACIEL JÚNIOR, Paulo Ditarso.
Resumo:
With the emergence of the cloud computing paradigm and the continuous search to reduce
the cost of running Information Technology (IT) infrastructures, we are currently experiencing an importam change in the way these infrastructures are assembled, configured and managed. In this research we consider the problem of managing a hybrid high-performance computing infrastructure whose processing elements are comprised of in-house dedicated machines, virtual machines acquired from cloud computing providers, and remote virtual machines made available by a best-effort peer-to-peer (P2P) grid. The applications that run in this hybrid infrastructure are characterised by a utility function: the utility yielded by the completion of an application depends on the time taken to execute it. We take a business-driven approach to manage this infrastructure, aiming at maximising the total profit achieved. Applications are run using computing power from both in-house resources and the best-effort grid. whenever possible. Any extra capacity required to improve the profitability of the infrastructure is purchased from the cloud computing market. We also assume that this extra capacity is reserved for future use through either short or long term contracts, which are negotiated without human intervention. For short term contracts. the cost per unit of computing resource may vary significantly between contracts, with more urgent contracts normally being more expensive. Furthermore, due to the uncertainty inherent in the besteffort grid, it may not be possible to know in advance exactly how much computing resource will be needed from the cloud computing market. Overestimation of the amount of resources required leads to the reservation of more than is necessary; while underestimation leads to the necessity of negotiating additional contracts later on to acquire the remaining required capacity. In this context, we propose heuristics to be used by a contract planning agent in order to balance the cost of running the applications and the utility that is achieved with their execution. with the aim of producing a high overall profit. We demonstrate that the ability to estimate the grid behaviour is an important condition for making contracts that produce high efficiency in the use of the hybrid IT infrastructure.