Programmable Overlay Network : PON

Introduction

Service-Oriented Computing (SOC) is becoming an increasingly popular paradigm for modelling and building distributed systems in heterogeneous, decentralised, and open environments. However, proposed Service-Oriented Architectures (SOA) are usually based on centralised components, such as service registries or service brokers, that introduce reliability, management, and performance issues. We propose, through the PON implementation, a fully decentralised Service-Oriented Architecture (see SmartTools) built on top of a self-organising peer-to-peer (P2P) infrastructure.

The main advantages and characteristics of PON are:

• Loose coupling components :

  The components have no dependencies to other components via interfaces. The resolution of the services required and provided, is made at the connection of the components.

• Self & dynamic description of components (Declarative Interface)
• Dynamic component connectivity
• Composite components
• Asynchronous communication model
• Automatic & Lazy remote connections
• Efficient messages transmission based on NIO Java API and concepts of Virtual Pipes
• Open to any other communication protocols
• Decentralized remote organisation based on peer-to-peer infrastructure
• Based on OSGi frame-work

Applications

Here is a sample application built with PON (see the version, transport1.3.zip)

This example shows an application of publication and discory of georeferenced services with peer-to-peer infrastructure. This example uses the GWT Google API and Google Map API. There are three types of agent (particular html page).

• On the left: the agent (manager) to create and publish a service to a geographic area.
• On the middle: the agent (provider) to list all the services and add meta-information.
• On the right: the agent (client) to select a position on the map and find all the services.

A Programmable Overlay Network (PON) is the association of the concept of Service-oriented architecture, Overlay Network and a Peer-to-Peer communication protocols.

Layers

There are three layers to realize PON:

• Service Oriented Architecture of SmartTools
• Peer-to-Peer Overlay Network : DHT (Chord)
• Peer-to-Peer communication protocols : Virtual Pipes (as like JXTA)

Architecture

An Example of Functional Schema

Links

• SmartTools Software
• SmartTools Home Page