计算网格应用可用性的度量模型

计算网格是很容易变化的不可靠的计算环境，因此如何保证应用的可用性成为构建网格系统的关键问题之一，而首先要解决的问题是如何对计算网格的可用性进行度量，分析了计算网格可用性的特征，提出从应用的角度度量计算网格可用性的方法，并设计了一种度量计算网格中应用可用性的模型，在这一模型中，应用的可用性用一个串行RBD来描述，每个网格结点上运行的应用的任务的可用性用概率模型描述，以此模型为基础，首先分析了在计算网格中影响应用可用性的关键因素，之后讨论了该度量模型在构建计算网格高可用服务体系结构中的应用。

A Measurement Model for the Availability of Applications in Computational Grid

Computational grid is a more variable and unreliable computing environment. It should provide appropriate availability assurance for the applications. How to measure the availability is the key issue for providing high availability service. In this paper, the characteristics of the availability of computational grid are analyzed and it is proposed that the availability of computational grid should be measured from the applications' point of view. Then a measurement model for the availability of applications in the computational grid is presented. In this model the overall availability of a grid application is measured by using a serial RBD, and the availability of application's tasks on a grid node is measured by using a probabilistic model. This measurement model abstracts the key factors which affect the availability of applications in the computational grid. Then the usage of this measurement model in the high availability service architecture of the computational grid is discussed.