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REST data services overview
The WebSphere eXtreme Scale REST data service is a Java™ HTTP service that is compatible with Microsoft WCF Data Services (formally ADO.NET Data Services) and implements the Open Data Protocol (OData). Microsoft WCF Data Services is compatible with this specification when using Visual Studio 2008 SP1 and the .NET Framework 3.5 SP1.
The REST data service allows any HTTP client to access a data grid. The REST data service is compatible with the WCF Data Services support supplied with the Microsoft .NET Framework 3.5 SP1. RESTful applications can be developed with the rich tooling provided by Microsoft Visual Studio 2008 SP1. The figure provides an overview of how WCF Data Services interacts with clients and databases.
Figure 1. Microsoft WCF Data Services
WebSphere eXtreme Scale includes a function-rich API set for Java clients. As shown in the following figure, the REST data service is a gateway between HTTP clients and the WebSphere eXtreme Scale data grid, communicating with the grid through an WebSphere eXtreme Scale client. The REST data service is a Java servlet, which allows flexible deployments for common Java Platform, Enterprise Edition (JEE) platforms, such as WAS. The REST data service communicates with the WebSphere eXtreme Scale data grid using the WebSphere eXtreme Scale Java APIs. It allows WCF Data Services clients or any other client that can communicate with HTTP and XML.
Figure 2. WebSphere eXtreme Scale REST data service
Refer to the REST data services sample and tutorial, or use the following links to learn more about WCF Data Services.
- Microsoft WCF Data Services Developer Center
- ADO.NET Data Services overview on MSDN
- Whitepaper: Using ADO.NET Data Services
- Atom Publish Protocol: Data Services URI and Payload Extensions
- Conceptual Schema Definition File Format
- Entity Data Model for Data Services Packaging Format
- Open Data Protocol
- Open Data Protocol FAQ
This version of the eXtreme Scale REST data service supports the following features:
- Automatic modeling of eXtreme Scale EntityManager API entities as WCF Data Services entities, which includes the following support:
- Java data type to Entity Data Model type conversion
- Entity association support
- Schema root and key association support, which is required for partitioned data grids
See Entity model for more information.
- Create, Read, Update and Delete (CRUD) operations using the respective HTTP request methods: POST, GET, PUT and DELETE. In addition, the Microsoft extension: MERGE is supported.
- Simple queries, using filters
- Batch retrieval and change set requests
- Partitioned data grid support for high availability
- Interoperability with eXtreme Scale EntityManager API clients
- Support for standard JEE Web servers
- Optimistic concurrency
- User authorization and authentication between the REST data service and the eXtreme Scale data grid
Known problems and limitations
- Tunneled requests are not supported.
WebSphere eXtreme Scale overview
Cache integration overview
Transaction processing overview
Tutorials, examples, and samples
Program to access the REST data service
Configure the REST data service
REST data services sample and tutorial