Architecture

The architecture of a grid environment is described in the Open Grid Services Architecture (OGSA). With reference to the OGSA, grid services are seen as advancements of web services. They are geared to the principles of Service Oriented Architectures (SOA). SOA consider single computing components (servers, applications etc.) on the lowest level which will be combined as a kind of “orchestra” to logical services on higher levels. These services are accessible via standardized interfaces. Web services offer such standardized interfaces for client-server applications via internet-based protocols. Via web service description language (WSDL), all necessary information to access the offered service is described independently of platforms and machine-readable. Subsequently, client application and server service communicate via the SOAP network protocol to exchange data and start programs. The grid architecture adopts this principle and demands additional grid-specific infrastructural enhancements for the web services involved.  Grid services based on this pattern  make up the components which form the grid architecture:

  • Execution management components are responsible for the selection of an appropriate resource for a grid application as well as preparation, start and control of the application.
  • Data management components control access to data within a grid, transport of data in the grid, availability and security of the data, interconnection and transformation of the data as well as the providing of related meta-data.
  • Resource management components are responsible for the management of physical and logical resources, resource reservations, and the management of the grid infrastructure within the grid.
  • Security components control authorization and authentication between users and grid components and among grid components as well as the reliability and integrity of data exchange, allocation of responsibilities, recognition and defense of misuse.
  • Self-management components deal with automatic configuration, troubleshooting and optimization of grid components and applications.
  • Information services are responsible for publication and support of current information about the state and availability of grid applications and resources.

The OGSA was developed and is updated by the Open Grid Forum (OGF). OGF is a community of users, developers and companies striving towards a standardization of grid technologies. The current OGSA version 1.5 is described in: www.ogf.org/documents/GFD.80.pdf