2005年的老博，转到这个空间来。
The Anatomy of the Grid
网格结构
Enabling Scalable Virtual Organizations *
启动可升级的虚拟组织
Ian Foster
Mathematics and Computer Science Division, Argonne National Laboratory, Argonne, IL 60439.
Carl Kesselman
Department of Computer Science, The University of Chicago, Chicago, IL 60657.
Steven Tuecke
Information Sciences Institute, The University of Southern California, Marina del Rey, CA 90292.
{foster, tuecke}@mcs.anl.gov, carl@isi.edu
Abstract
摘要
“Grid” computing has emerged as an important new field, distinguished from conventional
distributed
computing by its focus on large-scale resource sharing, innovative
applications, and, in some cases, high-performance orientation. In this
article, we define this new field. First, we review the “Grid problem,”
which we define as flexible, secure, coordinated resource sharing among
dynamic collections of individuals, institutions, and resources—what we
refer to as virtual organizations. In such settings, we encounter
unique authentication, authorization, resource access, resource
discovery, and other challenges. It is this class of problem that is
addressed by Grid technologies. Next, we present an extensible and open
Grid architecture, in which protocols, services, application
programming interfaces, and software development kits are categorized
according to their roles in enabling resource sharing. We describe
requirements that we believe any such mechanisms must satisfy and we
discuss the importance of defining a compact set of intergrid protocols
to enable interoperability among different Grid systems. Finally, we
discuss how Grid technologies relate to other contemporary
technologies, including enterprise integration, application service
provider, storage service provider, and peer-to-peer computing. We
maintain that Grid concepts and technologies complement and have much
to contribute to these other approaches.
“网格”计算创造了一个重要的新领域，而不像传统的分布式计算那样关注大范围资源共享，革新应用和某
些情形下的高性能定位。本文中我们定义了这个新领域。首先，我们考察“网格求解”，一个我们定义之为，存在于动态的用户、机构与资源群体――也就是我们谈
到的虚拟组织（virtual
organizations）之间的，灵活，安全，协调的资源共享。在这样的情况下，我们遇到了一些独特的挑战，诸如鉴别，权限，资源存取，资源发现等。
网格技术就是处理这类问题的。然后，我们展示一个可扩展的开放的网格体系结构，其中的协议，服务，应用程序接口和软件开发包被按照其在资源共享中的不同作
用分门别类。我们将描述那些，相信任何这样的机制都必须要满足的要求，并论述定义一个网格内协议（intergrid
protocols）紧凑集对于实现不同网格系统之间互操作性的重要意义。最后，我们将论述网格技术怎样和其他当前技术结合的，包括企业整合，应用服务提
供者，存储服务提供者和点对点计算。我们认为网格的概念和技术将补充那些相关领域并做出很大贡献。
1 Introduction
1 前言
The term “the Grid” was coined in the mid1990s to denote a proposed
distributed computing infrastructure for advanced science and
engineering [34]. Considerable progress has since been made on the
construction of such an infrastructure (e.g., [10, 16, 46, 59]), but
the term “Grid” has also been conflated, at least in popular
perception, to embrace everything from advanced networking to
artificial intelligence. One might wonder whether the term has any real
substance and meaning. Is there really a distinct “Grid problem” and
hence a need for new “Grid technologies”? If so, what is the nature of
these technologies, and what is their domain of applicability? While
numerous groups have interest in Grid concepts and share, to a
significant extent, a common vision of Grid architecture, we do not see
consensus on the answers to these questions.
“the
Grid”这个名词诞生于90年代中期，用来表示一个为高级科学与工程技术提出的分布式计算基础设施[34]。巨大的发展从这个基础设施的建设起步了，但
是“网格（Grid）”这个词也被混合进去了，至少在大众观念里，用来涵盖从高级网络到人工智能的每件事。人们也许想知道这个词是否有真实的实体意义。真
的存在一个明显的“网格求解(Grid
problem)”并因而有新“网格技术”的需求？若真这样，这些技术的本质是什么，它们应用的领域是什么？当许多人对网格的概念和参与感兴趣的时候，在
某种重要程度上，关于网格体系结构的普遍看法，我们却没有看到一个一致答案。
Our purpose in this article is to argue that the Grid concept is
indeed motivated by a real and specific problem and that there is an
emerging, well-defined Grid technology base that addresses significant
aspects of this problem. In the process, we develop a detailed
architecture and roadmap for current and future Grid technologies.
Furthermore, we assert that while Grid technologies are currently
distinct from other major technology trends, such as Internet,
enterprise, distributed, and peer-to-peer computing, these other trends
can benefit significantly from growing into the problem space addressed
by Grid technologies.
本文中的一个目的就是要说明，网格概念确确实
实产生于真实和特殊的问题，而且，存在新兴的、定义明确的网格技术基础去解决问题的重大方面。在此过程中，我们为当前与将来的网格技术展开了一幅具体的体
系结构和道路图。此外，我们肯定网格技术不同于当前许多其他技术方向，比如因特网、企业、分布式、点到点计算，但这些其他的方向能因成为网格计算的问题域
而获益匪浅。
The real and specific problem that underlies the Grid concept is
coordinated resource sharing and problem solving in dynamic,
multi-institutional virtual organizations. The sharing that we are
concerned with is not primarily file exchange but rather direct access
to computers, software, data, and other resources, as is required by a
range of collaborative problem-solving and resource-brokering
strategies emerging in industry, science, and engineering. This sharing
is, necessarily, highly controlled, with resource providers and
consumers defining clearly and carefully just what is shared, who is
allowed to share, and the conditions under which sharing occurs. A set
of individuals and/or institutions defined by such sharing rules form
what we call a virtual organization (VO).
那些网格概念下的真正的特定的问题，是如何协调地共享资源，以及如何在动态的、公共机构复合形成的虚
拟组织中求解问题。我们所说的共享并不主要靠文件交换，而是在工业、科学、工程领域产生有合作性求解的需求时，直接对计算机、软件、数据、以及其他资源进
行存取。这种共享必定是高度控制的，资源提供者与用户把共享什么、允许谁共享、共享时的状态定义得清清楚楚。虚拟组织（VO）中的共享规则就定义了这样的
一组个人和/或机构。
The following are examples of VOs: the application service
providers, storage service providers, cycle providers, and consultants
engaged by a car manufacturer to perform scenario evaluation during
planning for a new factory; members of an industrial consortium bidding
on a new aircraft; a crisis management team and the databases and
simulation systems that they use to plan a response to an emergency
situation; and members of a large, international, multiyear high energy
physics collaboration. Each of these examples represents an approach to
computing and problem solving based on collaboration in computation-
and data-rich environments.
下面是VO的例子：一个汽车制造商评估建造一个新工厂时的应用服务提供者、存储服务提供者、销售和顾
问，投标制造新飞机的工业联合会会员；规划应急反应时所涉及的危机处理小组，数据库和模拟系统；一个国际大型的、常年设立的高能物理研究组织。这些都是利
用大规模的计算资源和数据资源环境进行科学计算和问题求解的例子。
As these examples show, VOs vary tremendously in their purpose,
scope, size, duration, structure, community, and sociology.
Nevertheless, careful study of underlying technology requirements leads
us to identify a broad set of common concerns and requirements. In
particular, we see a need for highly flexible sharing relationships,
ranging from client-server to peer-to-peer; for sophisticated and
precise levels of control over how shared resources are used, including
fine-grained and multi-stakeholder access control, delegation, and
application of local and global policies; for sharing of varied
resources, ranging from programs, files, and data to computers,
sensors, and networks; and for diverse usage modes, ranging from single
user to multi-user and from performance sensitive to cost-sensitive and
hence embracing issues of quality of service, scheduling,
co-allocation, and accounting.
正如上面的例子说的一样，在目标、范围、大小、生存期、结构、团体、社会形态上，VO差别迥异。然
而，在对该问题的技术需求深入研究之后，能发现它们具有许多共同点。特别是，我们看到了高度可扩展的共享关系：从C/S到P2P，需要复杂而又精密地控制
如何使用共享资源，包括细粒度以及多处同时享有资源式的存取控制、代理、本地应用和全球策略；从程序、文件和数据到计算机、传感器和网络，需要共享不同的
资源；从单用户到多用户，从性能优先到注重优先，需要各种各样的使用模式。由此产生的问题包括服务、规划、分配原则、会计行为的质量问题。
Current distributed computing technologies do not address the
concerns and requirements just listed. For example, current Internet
technologies address communication and information exchange among
computers but do not provide integrated approaches to the coordinated
use of resources at multiple sites for computation.
Business-to-business exchanges [57] focus on information sharing (often
via centralized servers). So do virtual enterprise technologies,
although here sharing may eventually extend to applications and
physical devices (e.g., [8]). Enterprise distributed computing
technologies such as CORBA and Enterprise Java enable resource sharing
within a single organization. The Open Group’s Distributed Computing
Environment (DCE) supports secure resource sharing across sites, but
most VOs would find it too burdensome and inflexible. Storage service
providers (SSPs) and application service providers (ASPs) allow
organizations to outsource storage and computing requirements to other
parties, but only in constrained ways: for example, SSP resources are
typically linked to a customer via a virtual private network (VPN).
Emerging “Distributed computing” companies seek to harness idle
computers on an international scale [31] but, to date, support only
highly centralized access to those resources. In summary, current
technology either does not accommodate the range of resource types or
does not provide the flexibility and control on sharing relationships
needed to establish VOs.
而当前的分布式计算技术不以上述内容为研究重点。如Internet技术研究计算机间的通讯和信息交
换，但不提供在不同场合协调使用资源进行计算的集成方法。B2B
交换[57]重点解决信息共享（通过中心服务器）。尽管虚拟企业的共享已扩充到应用程序和物理设备的共享了[8]，但它也还是如此。企业的分布式计算如
CORBA和J2EE实现了单个企业内的资源共享。分布式计算环境开放研究小组（DCE）支持站点间的安全共享，但大多数VO觉得这样负担太重而且扩展性
不强。存储服务者（SSP）和应用服务提供者（ASP）允许企业从外面获得存储资源和计算资源，但必须以限定的方式实现：如SSP的典型用法是用虚拟专用
网（VPN）。连接客户。正在兴起的“分布式计算”公司试图在国际性规模上使用空闲的计算机资源[31]，但目前为止，仅达到集中式地操作这些资源。总
这，当前这些技术要么不适于这么多资源种类，要么没对VO提供必要的共享资源的控制和灵活性。
It is here that Grid technologies enter the picture. Over the past
five years, research and development efforts within the Grid community
have produced protocols, services, and tools that address precisely the
challenges that arise when we seek to build scalable VOs. These
technologies include security solutions that support management of
credentials and policies when computations span multiple institutions;
resource management protocols and services that support secure remote
access to computing and data resources and the co-allocation of
multiple resources; information query protocols and services that
provide configuration and status information about resources,
organizations, and services; and data management services that locate
and transport datasets between storage systems and applications.
现在的网格技术有些眉目了。在过去的五年里，网格研究团队已研究出一些适用的协议、服务和工具，并使
它们能够在我们建设可升级的VO时接受考验。这些技术包括支持跨组织的信用和策略管理的解决方案、那些支持远程地对计算和数据资源进行安全访问以及在多资
源状况下进行并发分配的资源管理协议、那些提供资源、团体和服务的配置状态信息的查询协议和服务，还有那些在存储系统和应用系统之间定位和传输数据集的数
据管理服务。
Because of their focus on dynamic, cross-organizational sharing,
Grid technologies complement rather than compete with existing
distributed computing technologies. For example, enterprise distributed
computing systems can use Grid technologies to achieve resource sharing
across institutional boundaries; in the ASP/SSP space, Grid
technologies can be used to establish dynamic markets for computing and
storage resources, hence overcoming the limitations of current static
configurations. We discuss the relationship between Grids and these
technologies in more detail below.
GRID技术重点解决动态、团体间共享，所以它与其它已存的分布计算技术是补充而不是竞争关系。如：
企业分布计算系统使用网格技术实现机构边界的资源共享，在ASP/SSP领域，用网格技术可以建立计算资源和存储资源的动态分配，从而克服现有静态配置的
局限。在以后的章节中，还会详细介绍网格和这些技术的关系。
In the rest of this article, we expand upon each of these points in
turn. Our objectives are to (1) clarify the nature of VOs and Grid
computing for those unfamiliar with the area; (2) contribute to the
emergence of Grid computing as a discipline by establishing a standard
vocabulary and defining an overall architectural framework; and (3)
define clearly how Grid technologies relate to other technologies,
explaining both why emerging technologies do not yet solve the Grid
computing problem and how these technologies can benefit from Grid
technologies.
下面各章节，将依次展开介绍以上各点。作者的目标有三个：一是给非该领域的人介绍VO和网格的概念，二是为发展中的网格技术引入标准的专用术语和体系结构，三是介绍网格和其它技术的关系，解释为何其现在还没有解决网格计算的问题介绍这些技术将如何从网格技术中受益。
It is our belief that VOs have the potential to change dramatically
the way we use computers to solve problems, much as the web has
changed how we exchange information. As the examples presented here
illustrate, the need to engage in collaborative processes is
fundamental to many diverse disciplines and activities: it is not
limited to science, engineering and business activities. It is because
of this broad applicability of VO concepts that Grid technology is
important.
作者坚信VO有潜力大大改变我们使用计算机解决问题的方式，如同WEB改变了我们传递信息的方式。文
中的例子展示了，合作进程的开展不仅仅局限在科学、工程和商业活动，而是进行各种各样的学科活动的基本需要。
这正是因为此有着广泛应用前景的VO理念——网格技术便是其中要点。