Consider the implementation of Java RMI as a composite binding in Fractal. Discuss the extent to which such a binding can be both configurable and reconfigurable.

Question

What will be an ideal response?

Answer 1

Composite binding are like any other configuration in Fractal and can themselves be configured and reconfigured. That is, a composite binding has an associated software architecture in terms of components and bindings. It is therefore possible to provide a component-based implementation of Java RMI which teases apart the different aspects of the implementation, for example components responsible for providing proxies, naming, communication, location, and so on. The granularity of the composition can also be varied, for example, the communication module could further be broken down into different aspects such as the underlying transport protocol and the module implementing the required invocation semantics. This approach clearly lends itself to a more configurable approach. For example, rather than offering a range of semantics in an implementation (at-least-once, at-most-once and exactly-once) a given deployment could be configured to offer one, as required by that context. Similarly, the transport protocol could be configured to TCP or to an alternative transport mechanism, for example optimized for an ad hoc networking environment. Similarly, the approach lends itself to reconfiguration, for example changing the invocation semantics or transport protocol at runtime.