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WebSphere eXtreme Scale programming interfaces
WebSphere eXtreme Scale provides several features that are accessed programmatically using the Java™ programming language through application programming interfaces (APIs) and system programming interfaces.
WebSphere eXtreme Scale APIs
When you are using eXtreme Scale APIs, distinguish between transactional and non-transactional operations. A transactional operation is an operation that is performed within a transaction. ObjectMap, EntityManager, Query, and DataGrid API are transactional APIs that are contained inside the Session that is a transactional container. Non-transactional operations have nothing to do with a transaction, such as configuration operations.
The ObjectGrid, BackingMap, and plug-in APIs are non-transactional. The ObjectGrid, BackingMap, and other configuration APIs are categorized as ObjectGrid Core API. Plug-ins are for customizing the cache to achieve the functions that you want, and are categorized as the System Programming API. A plug-in in eXtreme Scale is a component that provides a certain type of function to the pluggable eXtreme Scale components that include ObjectGrid and BackingMap. A feature represents a specific function or characteristic of an eXtreme Scale component, including ObjectGrid, Session, BackingMap, ObjectMap, and so on. Typically, features are configurable with configuration APIs. Plug-ins can be built-in, but might require that you develop the own plug-ins in some situations.
You can normally configure the ObjectGrid and BackingMap to meet the application requirements. When the application has special requirements, consider using specialized plug-ins. WebSphere eXtreme Scale might have built-in plug-ins that meet the requirements. For example, if you need a peer-to-peer replication model between two local ObjectGrid instances or two distributed eXtreme Scale grids, the built-in JMSObjectGridEventListener is available. If none of the built-in plug-ins can solve the business problems, refer to the System Programming API to provide the own plug-ins.
ObjectMap is a simple map-based API. If the cached objects are simple and no relationship is involved, the ObjectMap API is ideal for the application. If object relationships are involved, use the EntityManager API, which supports graph-like relationships.
Query is a powerful mechanism for finding data in the ObjectGrid. Both Session and EntityManager provide the traditional query capability.
The DataGrid API is a powerful computing capability in a distributed eXtreme Scale environment that involves many machines, replicas, and partitions. Applications can run business logic in parallel in all of the nodes in the distributed eXtreme Scale environment. The application can obtain the DataGrid API through the ObjectMap API.
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). The REST data service allows any HTTP client to access an eXtreme Scale grid. It is compatible with the WCF Data Services support that is 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. For more details, refer to the eXtreme Scale REST data service user guide.
Parent topic:Plan to develop applications
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