Catálogo de publicaciones - libros

Grids today still need investigation in several areas to provide models and tools for developing high-level scalable applications. Grid middleware is an active research area that is bringing several results to Grid developers and users. The goal of this workshop is to provide a bridge between the application community and the developers of middleware services, especially in terms of parallel and distributed computing, with the following major issues: To gather current state of the art and new approaches in the areas of knowledge and data management, resource management and information systems To include work-in-progress contributions To provide a forum for exchanging the ideas between the users’ community and grid middleware developers To disseminate existing results and provide input to the CoreGRID Network of Excellence The CoreGRID Workshop on Grid Middleware was held in conjunction with Euro-Par 2006 in Dresden, August 28-29, 2006 and was organized by the three CoreGRID Institutes: the Institute on Knowledge and Data Management, the Institute on Grid Information, Resource and Workflow Monitoring Services and the Institute on Resource Management and Scheduling.

A Network Monitoring system is a vital component of a Grid; however, its scalability is a challenge. We propose a network monitoring approach that combines passive monitoring, a domain oriented overlay network, and an attitude for demand driven monitoring sessions. In order to keep into account the demand for extreme scalability, we introduce a solution for two problems that are inherent to the proposed approach: security and group membership maintenance.

Distributed storage systems are expected to serve a broad spectrum of applications, satisfying various requirements with respect to capacity, speed, reliability, security at low cost. Virtualization techniques allow flexible configuration of storage systems in order to meet resource constraints and application requirements. Violin provides block level virtualization that enables the extension of storage with new mechanisms and combining them to create modular hierarchies. Creating and maintaining such virtualization hierarchies however, is a complex task where a human system administrator is the most expensive and less efficient element. We introduced Conductor, an automated support system that tries to grasp human expertise with declarative rules that are applied to storage management. So far the initial, static configuration capabilities of Conductor have been elaborated. Static features however, are not sufficient for practical purposes as the storage system evolves, i.e. requirements, workloads, access patterns may change in time. This paper presents work in progress that is aimed at extending Conductor with supporting dynamic features. We introduce the concepts of global and directed reconfigurations and discuss their potential strengths and weaknesses.

OGSA-DQP is a Distributed Query Processing system for the Grid. It uses the OGSA-DAI framework for querying individual databases and adds on top of it an infrastructure to perform distributed querying on these databases. OGSA-DQP also enables the invocation of analysis services, such as Blast , within the query itself, thereby creating a form of declarative workflow system. DynaSOAr is an infrastructure for dynamically deploying web services over a Grid or a set of networked resources. The DynaSOAr view of grid computing revolves around the concept of services, rather than jobs where services are deployed on demand to meet the changing performance requirements. This paper describes the merging of these two frameworks to enable a certain amount of dynamic deployment to take place within distributed query processing.

In this paper, we explore the technologies behind the security models applied to distributed data access in a Grid environment. Our goal is to study a security model allowing data integrity, confidentiality, authentication and authorization for VO users. We split the process for data access in three levels: Grid authentication, Grid authorization, local enforcement. For each level, we introduce at least one possible technological solution. Finally, we show our vision of a SOA oriented security framework. This work is developed as part of the CoreGRID Network of Excellence, for the Institute on Knowledge and Data Management.

This paper presents an analysis of security requirements of large-scale distributed file systems. Our objective is to identify their generic as well as specific security requirements and to propose potential solutions that can be employed to address these requirements. FileStamp – a multi-writer distributed file system developed at CETIC is considered as a case study for this analysis. This analysis yields that the existing range of security solutions can be employed to secure large-scale distributed file systems. However, they should be holistically employed to triumph over the security chinks in the FileStamp ’s armor.

We propose coupling based on contracts as a mechanism to address the problem of exchanging information between parties that require information to work together. Specifically, we show how our approach can be used to couple the deployment of an application with a Grid infrastructure deployment descriptor using ProActive[11,2]. To achieve this, we identify the properties related with information exchange between parties, and we group the properties of interest into typed clauses. We then propose that interfaces can be built using shared typed clauses. If the interfaces between parties are compatible, the coupling of the interfaces can yield a coupling contract. The clauses belonging to the contract represent what information can be shared between the parties, and the type of the clause specifies how this information will be shared. Finally, we show how the deployment of applications on the Grid can benefit from the proposed approach. Unfamiliar applications can couple with deployment descriptors to deploy on alien Grids, without modifying or inspecting neither of them.

The use of grid computing to easily and efficiently execute data and compute-intensive applications strongly depends on new software development approaches able to separate application-domain aspects from non-functional ones, such as task mapping and deployment. In this paper, we present an object-oriented framework that is able to transparently transform non-distributed programs into hierarchical master-slave ones, and to map and schedule them onto a grid computing system. Moreover, the framework is able to leverage services delivered by the underlying middleware platform, such as resource management and communication, to satisfy user requirements. The paper presents the framework architecture, a reflection-based implementation and its evaluation atop of a hierarchical grid middleware.

This paper presents the integration of a multi-level scheduler in the YML architecture. It demonstrates the advantages of this architecture based on a component model and why it is well suited to develop parallel applications for Grids. Then, the multi-level scheduler under development for this framework is presented.

To assure secure access to any computer resources one must provide an adequate level of authentication, authorization job isolation and possibility of auditing user actions. In the grid environment that comprises a large number of users and resources in different administrative domains, these features are challenging. Grid economy and accounting related to it are becoming more and more important in an emerging aspect of grid commercialization. Also, the requirements of the users and administrators are becoming more and more sophisticated: checkpointing and migration of jobs, detailed software requirements, quality of service, collaborative work, and load balancing, to name a few. Virtualization techniques, nowadays more and more matured and advanced, seem to help solve the above-mentioned problems. In the present paper we discuss some of these techniques as well as existing solutions and then propose a framework for Virtual Environments. The framework focuses on resource access control, but the benefits of virtualization are wider.