ITR/SY Collaborative Research: A Unified Relational Approach to Grid Information Services

在分布式计算环境(如计算网格)中运行的应用程序必须适应可用的硬件和软件资源。这需要有关网格资源属性的信息，如主机、网络交换机、链接和路径、软件库和系统、用户和组织权限、软件服务、事件频道和词典等。应用程序运行所需的信息、信息的值(信息更改的速度)和信息的新鲜度(更新必须以多快的速度推送到应用程序)可能会有很大的差异。这些特性对资源信息服务提出了很大的需求，这些需求也是随着目录服务的一般领域的日益普遍而产生的。网格论坛是一个全球网格计算的国际标准机构，它正在制定表示和查询这些信息的标准。这些不断发展的标准有很多优点，但在这些系统中执行许多形式的高度可取的查询将是困难或昂贵的。特别是，动态信息将需要非常高的更新率，这是基于LDAP的实现所不支持的。该项目将通过提出的(暂定名称)网格资源信息服务(GRIS)来解决这些问题，GRIS是网格信息服务的统一关系方法。研究将从关系数据库系统的完整ACID(原子性/一致性/隔离性/持久性)功能开始，并“构建”到一个实用的资源信息系统，它仍然提供RDBMS的大部分好处。这样的系统将为所有类型的网格资源信息提供单一的高度灵活的查询模型和语言，无论其如何动态。这项研究将最终实现一种基于商用数据库系统和SQL语言的可扩展实现，包括为非SQL用户提供的“罐头查询”。该项目将使用从现有网格信息服务记录的更新和查询来评估新系统和技术，并将结果与Globus MDS2等分层系统进行比较。为了便于比较，该项目将通过与用户、工具开发人员和网格论坛成员的讨论生成一组基准查询，并将量化这些查询的限制。

An application running in a distributed computing environment such as the Computational Grid must adapt to the available hardware and software resources. This requires information about the properties of Grid resources such as hosts, network switches, links and paths, software libraries and systems, user and organization rights, software services, event channels and dictionaries, and more. The information needed for an application to run, the values of the information (how fast the information changes) and the freshness of the information (how fast updates must be pushed to the application) can vary dramatically. These attributes place significant demands on the resource information service, demands that are arising with increasing prevalence in the general area of directory services as well. The Grid Forum, an international standards body for world-wide Grid computing, is developing standards for representing and querying this information. There is much that is excellent about these evolving standards, but there are many forms of highly desirable queries that will be difficult or expensive to perform in these systems. In particular, dynamic information will require very high update rates not supported by LDAP-based implementations.This project will address these concerns through a proposed (and tentatively named) Grid Resource Information Service (GRIS), a unified relational approach to grid information services. The research will start with the full ACID (Atomicity/Consistency/Isolation/Durability) functionality of a relational database system and "build down" to a practical resource information system that still provides most of the benefits of the RDBMS. Such a system will provide a single highly flexible query model and language for all types of Grid resource information, no matter how dynamic. The research will culminate in an extensible implementation based on commodity database systems and the SQL language, including "canned queries" for non-SQL users. The project will evaluate the new system and techniques using logged updates and queries from an existing Grid information service, and comparing results with a hierarchical system such as Globus MDS2. To facilitate comparisons, the project will produce a set of benchmark queries from discussions with users, tool developers, and Grid Forum members, and will quantify the limits of these queries.