Single Object Invocation

When objects stored in the ScaleOut distributed data grid are large and complex, a conventional CRUD (Create/Read/Update/Delete) access model can be inefficient when only a small portion of an object’s state needs to be accessed. Invoking a method directly on the ScaleOut hosts where the object resides is often faster than pulling the entire object to a client to access its members.

The ScaleOut service provides the cache.singleInvoke operation, allowing a method to be invoked directly on the server where an object resides. This server-side method can receive an abitrary argument object from the caller and return an arbitrary payload (a “result object”) back to the caller.

Conceptually, a Single Object Invocation operation is similar to a post event operation, with two important differences:

• cache.postEvent operations are handled sequentially for a given key, whereas cache.singleInvoke operations may execute different handlers on the same key in parallel to handle simultaneous requests.

• cache.postEvent is intended for streaming event scenarios, and the caller will not receive a result value back from the handler. cache.singleInvoke operations can return values back to the caller.

• Invoking Server-side Methods on a Single Object
  • Example SMI
  • Using singleInvoke
  • Unhandled Exceptions
• Handling Server-side Methods on a Single Object
  • Hosting Server-Side Code
  • Registering an Invocation Handler