Introduction on gLite

For any Grid computing effort, middleware is a crucial component. For EGEE, it was decided that a two-phase approach would be the best way forward. Originally, EGEE used middleware based on work from its predecessor, the European DataGrid (EDG) project, later developed into the LCG middleware stack, which was used on the EGEE infrastructure early in the project. In parallel, EGEE has developed and re-engineered most of this middleware stack into a new middleware solution, gLite, now being deployed on the pre-production service. The gLite stack combines low level core middleware with a range of higher level services. Distributed under a business friendly open source license, gLite integrates components from the best of current middleware projects, such as Condor and the Globus Toolkit, as well as components developed for the LCG project. The product is a best-of-breed, low level middleware solution, compatible with schedulers such as PBS, Condor and LSF, built with interoperability in mind and providing foundation services that facilitate the building of Grid applications from all fields.

Several academic and industrial research centres are collaborating in the development of the software, organised in a number of different activities: Data Management, Workload Management, Information and Monitoring, Accounting, Computing Element, Logging and Bookkeeping, Security and Network Monitoring and Provisioning. Development and deployment are also supported by EGEE’s extensive t-infrastructure (training infrastructure) programme. This provides support ranging from online documentation to live seminars and webcast tutorials. Training is also available on the dedicated GILDA dissemination testbed, featuring its own Certification Authority (CA), and allowing users and system administrators to test all aspects of deployment and use of gLite.

The gLite Grid services follow a Service Oriented Architecture, meaning that it will be easy to connect the software to other Grid services, and also that it will facilitate compliance with upcoming Grid standards, for instance the Web Service Resource Framework (WSRF) from OASIS and the Open Grid Service Architecture (OGSA) from the Global Grid Forum. The gLite stack is envisaged as a modular system, allowing users to deploy different services according to their needs, rather than being forced to use the whole system. This is intended to allow each user to tailor the system to their individual situation. Building on experience from EDG and LCG middleware development, gLite adds new features in all areas of the software stack. In particular it features better security, better interfaces for data management and job submission, a re-factored information system, and many other improvements that make gLite easy to use as well as effective. Already deployed on the various testing and pre-production Grids of the project, the rollout of gLite over the pre-production service is in progress.

Anyone interested in gLite is encouraged to try it out using GILDA, EGEE’s dedicated dissemination testbed. This can be easily accessed through the “Try the Grid” walkthrough (follow this link). Here you can join our test Virtual Organisation, submit jobs and get a feeling for the system. To get hold of the full version of gLite for deployment on your system, the gLite website (see link below) holds the software repository as well as all the necessary documentation, both online and for download.

Launched in 2004 by the EGEE partner INFN, GILDA (the Grid INFN virtual Laboratory for Dissemination Activities) is a fully working Grid testbed devoted to dissemination activities, and allows both users and system administrators access to first hand experience with Grid systems. In the context of EGEE, GILDA acts as a crucial component of the project’s t-Infrastructure (training infrastructure) programme, helping to pass on knowledge and experience, as well as computing resources, to the scientific community and Industry.

The GILDA testbed consists of 20 sites on three continents, using heterogeneous hardware to act as a ‘real world’ grid environment. It is made up of all the components of a larger Grid project, including testing and monitoring systems. To allow use of the testbed by any interested party, it also features a Virtual Organisation and a real Certification Authority (CA) that grants two-week certificates for the test use of the GILDA infrastructure. To tailor GILDA to the t-Infrastructure needs of EGEE, it features a number of different portals for different uses, including basic portals for first time users and full featured ones for more in depth tutorials and demonstrations.

GILDA fits seamlessly into the EGEE training and dissemination activities on a number of levels. It acts as a first point of contact for new users, allowing them quick and easy access to a working Grid and experience with the system of Virtual Organisations and CA used in Grids across the world. Later, it also acts as a resource for EGEE training activities such as demonstrations, tutorials and hands-on sessions. So far it has been used for more than 12p induction courses and demonstrations, with its website generating in excess of 1,500,000 hits. Finally, GILDA acts as a miniproduction environment, allowing users to test applications ported to the EGEE infrastructure.