Recent trends in Grid Computing indicate that the standardization of the Grid programming model and associated management services is still under progress. The Open Grid Services Architecture9 (OGSA) represents an evolution towards a Grid system architecture based on Web services. OGSA compliant, higher-level functions are beginning to be implemented. Therefore, GARUDA has adopted a pragmatic approach for using existing Grid infrastructure and Web Services technologies. The deployment of grid tools and services for GARUDA will be based on a judicious mix of in-house developed components, the Globus Toolkit (GT) and industry grade components. GT210 will be deployed on the GARUDA grid for operational requirements while researchers will experiment with GT411 at the Grid labs.
The resource management and scheduling in GARUDA is based on a deployment of industry grade schedulers in a hierarchical architecture. At the cluster level, scheduling is achieved through Load Leveler12 for AIX platforms and Torque13 for Solaris and Linux clusters. At the Grid level, the Moab14 scheduler from Cluster Resources15 interfaces with the various cluster level schedulers to transparently map user requests onto available resources in the Grid. Moab supports advanced features including intelligent data staging, co-allocation and multi-sourcing, service monitoring and management, sovereignty (local vs. central management policies), virtual private cluster and virtual private grid. Moab interfaces with Globus for data and user management, job staging and security.
To enable data oriented applications, GARUDA provides an integrated but distributed data storage architecture by deploying the Storage Resource Broker16 (SRB) from Nirvana.17 SRB creates and maintains a Global Namespace across multiple heterogeneous and distributed storage systems in the Grid. The Global Namespace is a hierarchical organization of all collections, sub-collections, and data objects in the SRB Federation, independent of their physical storage infrastructure. Access is virtualized through a single sign-on and interface through one common set of APIs. The SRB provides advanced services including transparent data load and retrieval, data replication, persistent migration, data backup and restore, and secure queries. Data security is ensured through the following mechanisms: authentication, authorization, tickets, encryption, access control lists, audit trails and role based classification of users. SRB achieves performance through parallel I/O, bulk operations, latency minimization, scalable implementation and a transaction based architecture. Data management is also automated through launch of daemons automatically on start-up.
Program Development Environment (PDE) enables users to carry out an entire program development life cycle for the Grid. During the program development cycle the user prototypes, implements, debugs and tunes his application. PDEs help users to express, manipulate and manage complex workflows, and also facilitate development using Grid specific programming languages such as scripting languages and workflow languages. They also help to reduce the complexities of understanding different environments as they act as a standard environment across all the resources of the Grid.
The GARUDA PDE includes basic program development tools such as editors and compilers; program analysis tools like debuggers and profilers; workflow environments and tools that help in porting, conversion and scalability. For a seamless interface to the user it would be ideal if all these components are made available through an Integrated Development Environment (Grid IDE). In the initial phase of the project the work will be focused towards delivering a debugger for the grid environment. This debugger will have features similar to DIViA,18 which is an integrated debugging environment available on the PARAM clusters.
The GARUDA portal, which provides the user interface to the Grid resources, hides the complexity of the Grid from the users. It allows submission of both sequential and parallel jobs and also provides job accounting facilities. Problem Solving Environments (PSE) in the domains of Bio-informatics, Cryptanalysis and Community Atmospheric Model support the entire cycle of problem solving for the specific domains by supporting problem formulation, algorithm selection, numerical simulation and solution visualization.
Access to the Grid resources can either be through the high-speed communication fabric or over the Internet. Access through satellite based communication channels is also being explored as part of a research initiative to integrate the GARUDA terrestrial grid with a satellite based grid. Research on Semantic Grids is underway in collaboration with MIT,19 Chennai. The initial focus will be on publishing and intelligent discovery of Grid services. These capabilities will be integrated with the GARUDA portal to make access to the Grid seamless to the users.
