Job processing and data transfer are the main computing activities on the WLCG infrastructure. Reliable monitoring of the job processing on the WLCG scope is a complicated task due to the complexity of the infrastructure itself and the diversity of the currently used job submission methods. The paper will describe current status and the new strategy for the job monitoring on the WLCG scope, covering primary information sources, job status changes publishing, transport mechanism and visualization.

The world's largest scientific machine - the large hadron collider (LHC), situated outside Geneva, Switzerland - will generate some 15PB of data at rates up to 1.5 GB/s (in the case of the heavy-ion experiment, ALICE) to tape per year of operation. The processing of this data will be performed using a world-wide grid, the (worldwide) LHC computing grid built on top of the enabled grid for e-science and open science grid infrastructures. The LHC computing grid, which has offered a service for over two years now, is based upon a tier model comprising some 150 sites in tens of countries. In this paper, we describe the data management middleware stack - one of the key services provided by data grids. We give an overview of the different services implemented, a disk-based storage system which can support encryption, tools to manage the storage system and access files, the LCG file catalogue, and the file transfer service. We also review the relationship between these services.

The Large Hadron Collider (LHC) at CERN, the European Organisation for Nuclear Research, will produce unprecedented volumes of data when it starts operation in 2007. To provide for its computational needs, the LHC Computing Grid (LCG) is being deployed as a worldwide computational grid service, providing the middleware upon which the physics analysis for the LHC will be carried out. Data management middleware will be a key component of the LCG, enabling users to analyse their data without reference to the complex details of the computing environment. In this paper we review the performance tests of the LCG File Catalog (LFC) and make comparisons with other data management catalogs. We also survey the deployment status of the LFC within the LCG.

Within the European DataGrid project, Work Package 2 has designed and implemented a set of integrated replica management services for use by data intensive scientific applications. These services, based on the web services model, enable movement and replication of data at high speed from one geographical site to another, management of distributed replicated data, optimization of access to data, and the provision of a metadata management tool. In this paper we describe the architecture and implementation of these services and evaluate their performance under demanding Grid conditions.

Within the European DataGrid project, Work Package 2 has designed and implemented a set of integrated replica management services for use by data intensive scientific applications. These services, based on the web services model, enable movement and replication of data at high speed from one geographical site to another, management of distributed replicated data, optimization of access to data, and the provision of a metadata management tool. In this paper we describe the architecture and implementation of these services and evaluate their performance under demanding Grid conditions.

We describe the architecture and initial implementation of the next-generation of Grid Data Management Middleware in the EU DataGrid (EDG) project. The new architecture stems out of our experience and the users requirements gathered during the two years of running our initial set of Grid Data Management Services. All of our new services are based on the Web Service technology paradigm, very much in line with the emerging Open Grid Services Architecture (OGSA). We have modularized our components and invested a great amount of effort towards a secure, extensible and robust service, starting from the design but also using a streamlined build and testing framework. Our service components are: Replica Location Service, Replica Metadata Service, Replica Optimization Service, Replica Subscription and high-level replica management. The service security infrastructure is fully GSI-enabled, hence compatible with the existing Globus Toolkit 2-based services; moreover, it allows for fine-grained authorization mechanisms that can be adjusted depending on the service semantics.

The current architecture stems from our experience together with the user requirements gathered during the two years of running our initial set of Grid Data Management Services. All of our new services are based on the Web Service technology paradigm, very much in line with the emerging Open Grid Services Architecture (OGSA). We have modularized our components and invested a great amount of effort in developing secure, extensible and robust services, starting from the design but also using a streamlined build and testing framework.