This page explains the interest of a solution such as Petals ESB and in which situations its brings an additional value.
To ease the comprehension, it also introduces some scenarios involving Petals ESB within Information Systems.

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{note}NDLaurent : Première version de la page What is. La première partie sera à terme déplacée dans une page dédiée, visible depuis l'accueil du wiki. De même, la description actuelle déborde un peu sur la présentation générale de la plateforme Petals (à créer). {note}
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h1. What is an Enterprise Service Bus?

h2. From EAI to ESB

The notion of enterprise service bus was born several years ago, as a renewal of Entreprise Applications Integration solutions.
The Enterprise Applications Integration encompasses all middleware products, aiming for a better communication between one's applications, thus sparing costly point-to-point dedicated interfaces, and/or allowing better adequation of one's IS to enterprise organisation.
Traditionally, such solutions were proprietary ones. In the recent years, several factors revealed the need for a new integration model: great increase in entreprise use of business softwares, boom of internet exchanges with clients/partners/administration, lack of interoperability between concurrent EAI solutions...
Due to all of this, a new wave of products emerged: the Enterprise Services Bus.

h2. ESB Technology Overview

An Enterprise Service Bus keeps the same core concept as traditional solutions, but brings major assets:
- standard integration interface: using a standard pivot format, such as XML;
- standard communication protocols;
- message routing;
- data transformation;
- services exposure for external exchanges.

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An enterprise service bus (ESB) consists of a software architecture construct which provides fundamental services for complex architectures via an event-driven and standards-based messaging-engine (the bus).
Source: [Wikipedia|http://en.wikipedia.org/wiki/Enterprise_Service_Bus]
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The general idea of an Enteprise Service Bus is to provide a full-featured platform answering integration, routing, transformation and exchanges in a flexible, interoperable and resilient way.
ESB are also a solution of choice for adoption of modern infrastructure, based on a Service Oriented Architecture (SOA).
[Read more about ESBs on Wikipedia|http://wikipedia.org/wiki/Enterprise_Service_Bus]

Choosing a middleware clusters reduce this risk but adds great complexity to the infrastructure.
Petals ESB chose the third way, using a P2P-like approach: the container can be installed on several machines, each one hosting its set of services, router and shared registry of services.
- high availability, thus SLA respect, thanks to replication of services on several nodes and intelligent routing;

h2 Monitoring and Orchestration capabilities
By combining Petals BPEL/SCA service engines and our dedicated IDE, Petals Studio, you can easily assemble individual services to form business processes, with GUI and code validation.

- médiation
- peut-être mise en page pour chaque cas :

* schéma expliquant le concept, à sa droite Objectif > Produits utilisés
* paragraphe explicitant le concept
* lien vers fiche produit présentant exemple concret.
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