A basic premise of OGSA is that everything is(71)by a service: a network enabled entity th

Question

A basic premise of OGSA is that everything is(71)by a service: a network enabled entity that(72)some capability through the exchange of messages. Computational resources, storage resources, networks, programs, databases, and so forth are all(73). This adoption of a uniform. service-oriented model means that all components of the environment are virtual. More specifically, OGSA represents everything as a Grid service: a Web service that conforms(74)a set of conventions and supports standard interfaces for such purposes as lifetime management. This core set of consistent interfaces, from which all Grid services are implemented,(75)the construction of hierarchical, higher-order services that can be treated in a uniform. way across layers of abstraction.

A．defined

B．represented

C．used

D．passed

Answer 1

正确答案：B
解析：OGSA的一个基本前提是任何事务都表示成一个服务：一个网络可达的、通过消息交换提供某些能力的实体。计算资源、存储资源、网络、程序、数据库等都是服务。采用一个统一的面向服务的模型意味着环境中的所有组件都是虚拟的。更明确地说，OGSA将所有事务都表示成一个Grid服务：遵循一套规范并支持为了实现生命周期管理等类似目的而制定的标准接口的Web服务。这些一致接口的核心集，是所有的Grid服务实现的基础，便于高级服务的构造，而高级服务能够跨多个抽象层以一种统一的方式进行处理。