The Comet Middleware Project
Quick links :
- Overview
- Savannah Summary
- Documentation
- Download
- Links
Overview
The Comet middleware project is a Java-based environment that supports the
implementation and execution of distributed applications based on:
- Components : implementing the application logic
- Events : structured data that are exchanged by components
If compared to Object-oriented middleware approaches such as RMI, Comet
is quite different.
First, it implements asynchronous, multicast communication (in an efficient way, above the socket layer)
, synchronization being done through asynchronous hand-shakes. This offers
increased efficiency and expressivity for modern distributed systems such as
Peer-to-peer or publish/subscribe systems. The extensions for client/server hides
most of these underlying features.
Second, components do not make explicit reference to external references so that
the architecture of the application may be composed and changed at runtime.
Components are externally related by establishing dynamically typed connexions
(in fact, multicast in a consequence of this).
Third, component internals may also be changed at runtime, through a
"protocol & role" feature.
Finally, objective mobility (i.e. mobility of components that do not know
they are moving) is supported both with shallow and strong migration
(strong migration is more transparent but is costly, especially in Java)
The middleware is composed of two layers:
- The Scope Language, used to describe components
(plain Java is possible but more verbose)
- The Comet Kernel, which is a distributed infrastructure to run components
(without any centralized part)
The Comet Middleware is a Research Project developped jointly at The University of Tokyo - Japan
and Laboratoire d'Informatique de Paris 6 - France
Documentation
Under construction ...
Download
Links
Under construction ...