The basic problem Manage, transfer and access distributed data services and resources Some use-cases Replicating data for performance and reliability using high-performance data transfer Federating distributed data via a common access interface Managing file-based data and corresponding relational metadata Issues to address Many different data “types” and protocols Multiple possible use-cases, from high-energy physics to business How can we describe the data? How can we find the data? Where is the data needed ?
04/06/11 Gargi shankar verma The Open Grid Services Architecture
Open Grid System Architecture By Gargishankar Verma Reader – RCET Bhilai Dept- Information Technology 04/06/11 Gargi shankar verma
The `Open Grid Services Architecture` (`OGSA`) describes an architecture for a service-oriented grid computing environment for business and scientific use, developed within the Global Grid Forum (GGF).
OGSA is based on several other Web service technologies, notably WSDL and SOAP.
OGSA is a distributed interaction and computing architecture based around services, assuring interoperability on heterogeneous systems so that different types of resources can communicate and share information.
OGSA has been described as a refinement of the emerging Web Services architecture, specifically designed to support Grid requirements.
OGSA has been adopted as a grid architecture by a number of grid projects including the Globus Alliance .
SOA & Web Services: Key Benefits Gargi shankar verma 04/06/11
Locate services on any server
Relocate as necessary
Prospective clients find services using registries
Add & remove services as demand varies
Update implementations without disruption to users
On failure, clients query registry for alternate services
Growing number of industry standards
Strong industry support
Harness robust development tools for Web services
Decrease learning & implementation time
Embrace and extend
Leverage effort in developing and driving consensus on standards
Focus limited resources on augmenting & adding standards as needed
Virtualizing Resources Gargi shankar verma 04/06/11 Access Storage Sensors Applications Information Computers Resource-specific Interfaces Common Interfaces Type-specific interfaces Resources Web services
A Service-Oriented Grid Gargi shankar verma 04/06/11 Brokering Service Registry Service Data Service CPU Resource Printer Service Job-Submit Service Compute Service Notify Advertise Application Service Virtualized resources Grid middleware services
04/06/11 Gargi shankar verma A Closer Look at OGSA
Manage, transfer and access distributed data services and resources
Issues Find Describe Access Data Data Formats Protocols Use cases Data Data Data Data Move/Copy/Replicate Metadata Data Manage Common access Derived data Catalog Sensor Data stream Text file Relational database
Basic Data Services Gargi shankar verma 04/06/11 Data Resources Transfer Protocols Storage Management Data Management Other Data Services Transfer Registries Non-OGSA client APIs & other services Managed Storage Data Resources Service interface Resource interface
Composite Data Services Gargi shankar verma 04/06/11 Data Service n Data Service 1 Data Service 2 Data Services Replication Cache Federation
Basic Data Interfaces Gargi shankar verma 04/06/11
Information Services Gargi shankar verma 04/06/11 Consumers Information Services
Provide management and access facilities for information about applications and resources in the grid environment Producers Asynchronous notification Retrieval Registry Logger Execution management Resource reservation Problem determination Accounting Application monitoring Load balancing Service discovery
In the simplest model, service providers constantly publish their data to the registry, and service consumers query the registry to find out what is available.
Various enhancements to this model are possible, such as organizing registries into a hierarchical directory, push information flow (subscription), or differentiate confidentiality levels in the published information.
Apart from a service discovery, the information system would also be used by the real-time monitoring services, as well as the optimizing frameworks that constantly collect and store the information on the state of services for later off-line analysis.
We have already described the security requirements in the Grid environment.
In an OGSA context, part of this functionality may be implemented as services.
Actions such as trust establishment, authentication, or authorization can each be performed by a specialized service.
Isolating responsible functions such as authentication in a service can simplify the overall system design and maintenance, as, for example, when security patches need to be applied.
Another example of a security service is a bridging service, which may be necessary in secure communication between administrative domains, to translate between the security credentials belonging to various domains using incompatible security technology.