High-performance execution in distributed computing environments often requires careful selection and configuration not only of computers, networks, and other resources but also of the protocols and algorithms used by applications. Selection and configuration in turn require access to accurate, up-to-date information on the structure and state of available resources. Unfortunately, no standard mechanism exists for organizing or accessing such information. Consequently, different tools and applications adopt ad hoc mechanisms, or they compromise their portability and performance by using default configurations. We propose a solution to this problem: a Metacomputing Directory Service that provides efficient and scalable access to diverse, dynamic, and distributed information about resource structure and state. We define an extensible data model to represent the information required for distributed computing, and we present a scalable, high-performance, distributed implementation. The dat...

After a short period of being not much more than a curiosity, the World-Wide Web quickly became an important medium for discussion, commerce, and business. Instead of holding just information that the entire world could see, web pages also became used to access email, financial records, and other personal or proprietary data that was meant to be viewed only by particular individuals or groups. This made it necessary to design mechanisms that would restrict access to web pages. Unfortunately, most current mechanisms are lacking in generality and flexibility---they interoperate poorly and can express only a limited number of security policies.

With the growth of the Internet as a whole, and the popularity of the World-Wide Web information system in particular, Uniform Resource Locators (URLs) have become the de facto standard for naming on-line resources. The usage of URLs on a large scale has highlighted their deficiences, and new technologies are being developed which attempt to address these - notably the Uniform Resource Name (URN) and Uniform Resource Characteristic (URC). This report outlines some of the problems with URLs, provides an introduction to URNs and URCs, and identifies areas where the approach adopted for the Simple Discovery Protocol may be a viable solution. 1 Preamble It is assumed that the reader is already familiar with the Internet, Uniform Resource Locators[1], and the World-Wide Web. There are now a large number of elementary texts which introduce these concepts, for example[2]. This report discusses problems arising from the current usage of URLs on the Internet, and introduces some possible so...

This document describes an overall strategy for deploying a Directory Service on the Internet, based on the OSI X.500 Directory Service. It then describes in more detail the initial steps which need to be taken in order to achieve these goals, and how work already undertaken by IETF WGs is working towards these goals. *****This is a second draft version of the document. Several ideas in the document are still open and remain to be filled. Steve Kent, a planned author, has not yet read the document. ***** The draft document will be submitted to the RFC editor as an informational document. Distribution of this memo is unlimited. Please send comments to the authors. INTERNET-DRAFT Internet Directory services June 1992 Contents 1 REQUIREMENTS 3 2 SUMMARY OF SOLUTION 3 3 INFORMATION FRAMEWORK 4 3.1 The technical model 4 3.2 Extending the technical model 4 3.3 The operational model 5 4 NAME ASSIGNMENT 5 5 DIRECTORY INFRASTRUCTURE 7 5.1 Short term requirements 7 5.2

Persistent, dynamic references (or links) to remote documents are an essential part of an online library. This thesis examines two distributed database systems, X.500 and the Domain Name System (DNS), upon which to build dynamic references. DNS was chosen and was used to design a model and build a sample dynamic reference system. This system seems to exhibit the scalability, robustness, usability, and efficiency necessary for building global distributed online libraries.

Persistent, dynamic references (or links) to remote documents are an essential part of an online library. This thesis examines two distributed database systems, X.500 and the Domain Name System (DNS), upon which to build dynamic references. DNS was chosen and was used to design a model and build a sample dynamic reference system. This system seems to exhibit the scalability, robustness, usability, and efficiency necessary for building global distributed online libraries.

This document aims at organisations who are using local and global electronic communication on a day to day basis and for whom using an electronic White Pages Service is therefore indispensable.

This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited

This memo provides information for the Internet community. This memo does not specify an Internet standard of any kind. Distribution of this memo is unlimited

Indexes[6] at NASA, Astrophysics work at FNAL[7], Princeton's[8] Sloane Digital Sky Survey, the STELAR project, Space Telescope Electronic Information System[9], the Southampton University Astronomy Group[10], the National Solar Observatory[11], Astrophysics work at the AHPCRC[12]. See also: space[13].