New Tools: JGrid - A Jini-based Universal Service Grid

Zoltan Juhasz
University of Veszprem

Future grid systems will have to be secure, dynamic, fault-resilient, self-healing, and should operate with minimal administration. Resources should appear on the grid in the form of services. Users - clients or programs alike - should have simple, seamless access to these services.

The architecture, operation and features of Jini Technology developed by Sun Microsystems make it ideally suited for grid environments:

1. Jini's service discovery enables spontaneous networking and system configuration
2. In a Jini network, resources (be they hardware or software) are exported to the network as services. Jini services, in turn, are virtualized by Java interfaces
3. A built-in leasing model can be used for maintaining soft state and automatically removing failed components
4. Jini's distributed events and transactions support asynchronous notification and atomicity
5. The extensive Jini security mechanism provides for integrity and trust management
6. Finally, downloadable user interfaces facilitate the deployment of adaptive and accessible user interfaces.

In spite of its potentials, Jini has not been tried and tested for grid purposes. The goal of the JGrid project is to design and develop a proof-of-concept grid infrastructure that tests and demonstrates the feasibility of Jini for creating grids.

Key areas of investigation include a service-oriented architecture and programming model, wide-area service discovery, security, uniform service access from various devices, providing service abstractions for computational resources, integration with non-Java environments, and providing application development support for grid developers.

The current version of the system includes a Jini Service Browser supporting dynamic user interfaces as well as service view definitions; a Compute Service for executing Java tasks; a BatchExecutor Service to run parallel PVM jobs on Condor pools; and a Storage Service for remote file space manipulation and file transfer.

Figure 1: The JGrid services browser

A new release before the end of this year will include secure versions of all services, new services such as computational brokers, a real-time multimedia service and a generic batch executor; as well as router and grid access point services for wide-area service discovery. Further releases in 2004 will add message-passing support to Java grid programs and graphical application development support based on the P-Grade development environment.

Our experience with Jini Technology and JGrid are very positive. Jini, indeed, seems to be a natural match for building dynamic grid systems. The fact that the system relies on Java interfaces and, in general, on object-oriented techniques, lead to very effective and efficient systems. JGrid can be installed and configured in a matter of minutes without specialized knowledge. To the end user, it provides seamless access to services, effectively providing a true desktop experience. For instance, job submission has now become a simple point-and-click operation, and it is simple to provide even more intuitive user interfaces. In summary, the system is more efficient, easier to install, use and manage than systems relying on other Grid technologies.

Figure 2: Job submission in JGrid

The JGrid project is a joint effort of the University of Veszprem, MTA SZTAKI, Eotvos University of Sciences and Sun Microsystems Hungary. The project is funded by the Hungarian Ministry of Education under the Infocommunications Technologies and Applications Programme (IKTA). It is hoped that the fully operational version of JGrid will be deployed and used by the ClusterGrid system as well, a national grid infrastructure initiative aiming to connect 2,000 computers nationwide into a computational grid system for the academic community.

More details,
the current API, an early implementation of the core services, as well as demonstration programs can be found at http://www.irt.vein.hu/jgrid. Feedback and comments from the community are warmly welcome.

Resource:

The JGrid project

ClusterGrid project

P-Grade

The Jini Web site

The Jini FAQ

Jini downloadable user interfaces