Fractal RMI Documentation

Fractal RMI is a set of Fractal components that provide a binding factory to create distributed bindings between Fractal components.

See:
Description

Packages

org.objectweb.fractal.api.control
org.objectweb.fractal.jonathan	Provides Fractal compliant sub classes of some Jonathan classes.
org.objectweb.fractal.rmi	Provides a protocol, an object adapter and a binder component.
org.objectweb.fractal.rmi.io	Provides a marshaller and unmarshaller factory component.
org.objectweb.fractal.rmi.registry	Provides a Fractal components registry component.
org.objectweb.fractal.rmi.stub	Provides a stub and skeleton factory component based on ASM.
org.objectweb.jonathan.apis.binding	Provides a set of classes and interfaces for application level identifiers, naming contexts and binders.
org.objectweb.jonathan.apis.kernel
org.objectweb.jonathan.apis.presentation	Provides a set of classes and interfaces for presentation protocols (marshallers and unmarshallers).
org.objectweb.jonathan.apis.protocols	Provides a set of classes and interfaces for communication protocols.
org.objectweb.jonathan.apis.protocols.ip	Provides a set of classes and interfaces refining the binding abstractions in the case of IP protocols, and introduces some connection management abstractions.
org.objectweb.jonathan.apis.resources	Provides a set of classes and interfaces dealing with resource management.
org.objectweb.jonathan.apis.stub_factories	Provides an interface for stub factories.
org.objectweb.jonathan.libs.helpers
org.objectweb.jonathan.libs.protocols.tcpip	Provides a set of classes giving access to the TCP/IP protocol stack.
org.objectweb.jonathan.libs.resources	Provides implementations for various resources and managers.
org.objectweb.jonathan.libs.resources.tcpip	Provides a default implementation for TCP/IP connection management.

Fractal RMI is a set of Fractal components that provide a binding factory to create distributed bindings between Fractal components. These components are based on the Jonathan framework. They can be used with any Fractal implementation.

In order to provide distributed bindings between Fractal components, Java RMI cannot be used, unless the Fractal Specification is changed to specify that each interface provided or required by a component must extend the java.rmi.Remote interface, and that all the methods of these interfaces must declare a java.rmi.RemoteException exception. For the same reason, the Jeremie personality of Jonathan cannot be used, since it is an RMI-like personality. The David personality of Jonathan could perhaps have been used for this purpose, but we found this solution too "heavy" (David requires many CORBA classes) and not very practical (in particular because of the IDL compiler). Note that these remarks apply to Jeremie too.

We therefore decided to implement our own "personality" on top of the Jonathan framework alone, without its personalities. This new "personality" is small and efficient. Moreover it does not need a static stub compiler, and does not impose constraints on remote interfaces, unlike Java RMI (the Interface interface plays the role of the Remote interface: the objects that implement this interface, namely the interfaces provided by Fractal components, are passed by reference, while all other objects are passed by value).

The set of Fractal components provided by Fractal RMI is depicted in red in the figure below (the black and gray components are provided by the core Jonathan framework). This figure also shows how these components can be bound to each other to get a functional Fractal RMI Binder component, which provides a NamingContext interface. Note that this "flat" architecture can be made more readable by using composite components and shared components.

Figure 1: "flat" architecture of the Fractal RMI binder.