Ogsa service taxonomy
- 1. Prof. Neeraj Bhargava Pooja Dixit Department of Computer Science School of Engineering & System Science MDS, University Ajmer, Rajasthan, India 1
- 2. the purpose of OGSA is to define standard approaches to, and mechanisms for, basic problems that are common to a wide variety of grid systems, such as communicating with other services, establishing identity, negotiating authorization, service discovery, error notification, and managing service collections. in Figure, the three principal elements of OGSA are the (i) Open Grid Services Infrastructure, (ii) OGSA services, and (iii) OGSA models: Figure OGSA components (shaded) and related profiles (dashed lines). 2
- 3. Building on both grid and Web services technologies, the OGSI defines mechanisms for creating, managing, and exchanging information among entities called grid services. A grid service is a Web service that conforms to a set of conventions (interfaces and behaviors) that define how a client interacts with a grid service. These conventions, and other OGSI mechanisms associated with grid service creation and discovery, provide for the controlled, fault-resilient, and secure management of the distributed and often long-lived state that is commonly required in distributed applications. OGSA services build on OGSI mechanisms to define interfaces and associated behaviors for various functions not supported directly within OGSI, such as service discovery, data access, data integration, messaging, and monitoring. OGSA models support these interface specifications by defining models for common resource and service types. 3
- 4. The GGF anticipates that these OGSA components will be supplemented by a set of environment-specific profiles addressing issues such as the following. ◦ Protocol bindings. Environment profiles enable interoperability among different grid services by defining common mechanisms for transport and authentication. These issues are not addressed by OGSI, but rather defined as binding properties, meaning that different service implementations may implement them in different ways. For example, “SOAP over HTTP” is a useful grid service transport profile. Another example of such a profile is the proposed GSSAPI profile for security context establishment and message protection using WS- SecureConversation and WS-Trust . ◦ Hosting environment bindings. Environment profiles of this sort enable portability of grid service implementations. For example, an “OGSA J2EE Profile” might define standardized Java APIs that allow for portability of grid services among OGSI-enabled J2EE systems. An “OGSA Desktop Grid Profile” could allow for interoperability among systems that allow untrusted (and untrusting) desktop computers to participate in distributed computations. An “OGSA Scientific Linux Profile” could define standard execution environments for computers that run scientific applications, specifying conventions for the locations of key executables and libraries, and for the names of certain environment variables. ◦ Sets of domain-specific services. Profiles of this sort define interfaces and models in addition to those defined within OGSA to address the needs of specific application domains. For example, an “OGSA Database Profile” might define a set of interfaces and models for distributed database management; an “OGSA eCommerce Profile” might define interfaces and models for e-commerce applications. 4