Directory Service

The software engineering discipline is experiencing a quick consolidation in the applica- tions development activities and the use of technologies and methodologies of web-based programming. In the web services arena some oriented and based practices for the con- struction of large scale software applications (i.e., distributed information systems) are beginning to appear. The software development practices based on web services

In distance learning applications, one of the advantages over traditional methods of education should be the opportunity for the selection of learning modules, and for students to acquire knowledge that is suited to their individual needs. Adaptations of existing educational services are proving inadequate for current needs and are giving way to requirements for an integrated and well-managed provision of on-demand education and training over networks. The work described in this paper presents a directory services ...

This paper concentrates on the issue of matchmaking in the context of web services. It provides a brief review of the difference between directory services and matchmaking facilities and explains why directories such as UDDI are important but insufficient for web services and need to be complemented with advanced matchmaking facilities. It discusses the requirements that web services place on matchmaking, namely symmetry of information exchange, the ability of each party to specify requirements of the other party, rich languages to describe services and their consumers as well as their demands, and the ability to dynamically update and configure what is being offered. These requirements are addressed by the Web Services Matchmaking Engine (WSME) – a powerful matchmaking engine capable of matching complex entities, and a Data Dictionary Tool for defining the language of the corresponding matchmaking process. The WSME matchmaking process and property and rules languages are described. An example of how a dynamic market for selling and buying Capacitors can be created with WSME is given. Finally, conclusions and possible future avenues of work are presented.

The CMS Integration Grid Testbed (IGT) comprises USCMS Tier-1 and Tier-2 hardware at the following sites: the California Institute of Technology, Fermi National Accelerator Laboratory, the University of California at San Diego, and the University of Florida at Gainesville. The IGT runs jobs using the Globus Toolkit with a DAGMan and Condor-G front end. The virtual organization (VO) is managed using VO management scripts from the European Data Grid (EDG). Gridwide monitoring is accomplished using local tools such as Ganglia interfaced into the Globus Metadata Directory Service (MDS) and the agent based Mona Lisa. Domain specific software is packaged and installed using the Distrib ution After Release (DAR) tool of CMS, while middleware under the auspices of the Virtual Data Toolkit (VDT) is distributed using Pacman. During a continuo us two month span in Fall of 2002, over 1 million official CMS GEANT based Monte Carlo events were generated and returned to CERN for analysis while being demonstrated at SC2002. In this paper, we describe the process that led to one of the world's first continuously available, functioning grids.

A major roadblock for fundamentally secure computing environments is the limited ability of indiviual users to specify personal data distribution. This is in part due to a lack of a consistent, complete and explicit way to define access rights on an appropriate level. A key property that is missing in current models are the dynamic aspects of evolving organizations. We

standard, provides a flexible and scalable service discoveryframework for IP networks. It can be deployed with or without a directory service. This paper presents mSLP, the Mesh-enhanced Service Location Protocol. mSLP enhances SLP with a fully-meshed peering Directory Agent (DA) architecture. Peer DAs exchange service registration information, and maintain the same consistent data for shared scopes. mSLP improves the reliability and consistency of SLP directory services. It also greatly simplifies Service Agent (SA) registrations in systems with multiple DAs. mSLP is backward compatible with SLPv2 and can be deployed incrementally. Keywords–Service discovery, Service Location Protocol, directory replication, fully-meshed peer relationship, reliability, consistency, scalability. 1

An IP mobility support protocol that enables personal and terminal mobility for IP-based applications is put forward. This protocol does not require new network entities or support from network service providers. It comprises an innovative IP-to-IP address mapping module at the network layer and an user agent to interact with a directory service server and correspondent nodes. It does not require a permanent IP address and a home server. It does not use tunnelling on mobile nodes nor alter route path of IP packets. In this paper, we describe our implementation and present our experimental results. Experiments show that this protocol works for UDP and TCP connections without affecting the throughput of the mobile node on a wireless LAN. Related works are also discussed and quantitatively compared. As an example, this protocol provides seamless execution for applications like VoIP and video conferencing on mobile nodes that roam across wireless networks.

The software engineering discipline is experiencing a quick consolidation in the applica- tions development activities and the use of technologies and methodologies of web-based programming. In the web services arena some oriented and based practices for the con- struction of large scale software applications (i.e., distributed information systems) are beginning to appear. The software development practices based on web services

Directory services (e.g., LDAP) are often used to keep sensitive information (e.g., data and user credentials) for critical systems such as domain control servers, DNS servers, access control services and public key infrastructure (PKI). In this paper, we present the first fault-and intrusion-tolerant directory service. Our system architecture leverages different techniques of distributed systems, dependability and security. We demonstrated the feasibility of the proposed architecture through a prototype implementation. The results show that our directory service performs good enough to sustain the requirements of IT infrastructures with more than 136K users. Resumo. Serviços de diretório (e.g., LDAP) são frequentemente utilizados para manter informações sensíveis (e.g., dados e credenciais de usuários) em sistemas críticos como serviços de controle de domínio, servidores DNS, mecanismos de controle de acesso e infra-estrutura de chaves públicas. Este artigo apresenta a primeira arquitetura e mecanismos para prover serviços de diretórios tolerante a falhas e intrusões. Para atingir este objetivo são empregadas diferentes técnicas de sistemas distribuídos, dependabilidade e segurança. A viabilidade da solução proposta é demonstrada através da implementação e avaliação de um protótipo que utiliza protocolos e técnicas avançadas de tolerância a falhas e intrusões. Os resultados demonstram que a solução proposta é boa o suficiente para suportar as demandas de infra-estruturas de TI com mais de 136K usuários.

Directory services are a genuine constituent of any distributed architecture which facilitate binding attributes to names and then querying this information, that is, announcing and discovering resources. In such contexts, especially in a business environment, Quality of Service (QoS) and non-functional properties are usually the most important criteria to decide whether a specific resource will be used. To address this problem, we present an approach to the semantic description and discovery of web services which specifically takes into ...

The NSF TeraGrid project has designed and constructed a federated integrated information service (IIS) to serve its capability publishing and discovery needs. This service has also proven helpful in automating TeraGrid's operational activities. We describe the requirements that motivated this work; IIS's system architecture, information architecture, and information content; processes that IIS currently supports; and how various layers of the system architecture are being used. We also review motivating use cases that have not yet ...