Exam Essentials

Know how to create .NET Remoting objects.  Create a host application that listens on a channel and registers the classes from the server DLL with the .NET Remoting infrastructure. Create a client application that instantiates remote objects and invokes their methods. Remember, .NET Remoting applications reference the System.Runtime.Remoting component.

Be familiar with the choices for channels and formatters.  The TCP channel uses the binary formatter by default. The HTTP channel uses the SOAP formatter by default. Know how to register a channel in both client and server code.

Understand the object serialization versus proxy objects.  Marshal-by-value objects are marked with a <Serializable> attribute or implement the ISerializable interface. When a remote call is made on a marshal-by-value object, the entire state of the object (and its data) is serialized and sent to the caller, where is it re-created in the caller's process. Method calls execute in the caller's process. marshal-by-reference objects inherit from MarshalByRefObject. When a remote call is made on a marshal-by-reference object, a proxy object is created on the caller. Method calls execute in the host process.

Understand the difference between client-activated and server-activated objects.  The client directly controls the lifetime of a client-activated object. When the client instantiates the client-activated object, it is created on the server. When a client instantiates a server-activated object, a proxy is created on the client. An object is not created on the server until the client calls a method.

A server-activated object can be SingleCall-a new instance of the object is created and destroyed with each method call for each client. A server-activated object can be a Singleton-a single instance of the object can exist for an extended period of time, and service multiple calls and multiple clients, and the Singleton exposes the same data to call clients.

Understand how lifetime leases affect an object's lifetime.  Certain properties of the object's lease can be set only at initialization time. The caller can extend the object's lifetime. When the object's lifetime lease expires, the object is marked as available for garbage collection.

Be familiar with the properties and methods of the ServiceController class. Know how to use the ServiceController to stop and start Windows services programmatically.

Understand how to use configuration files. Many properties can be set in XML configuration files. When using configuration files, you can instantiate an object simply by using the New keyword.

Understand how to use an asynchronous callback with remote method calls. Asynchronous calls keep your client's user interface responsive. Use the .NET Delegate object's BeginInvoke and EndInvoke methods to make asynchronous calls.