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Chapter 1. Preface
1.1. Business Integration
In order to provide a dynamic and competitive business infrastructure, it is crucial to have a service-oriented architecture in place that enables your disparate applications and data sources to communicate with each other with minimum overhead.
The JBoss Enterprise SOA Platform is a framework capable of orchestrating business services without the need to constantly reprogram them to fit changes in business processes. By using its business rules and message transformation and routing capabilities, JBoss Enterprise SOA Platform enables you to manipulate business data from multiple sources.
1.2. What is a Service-Oriented Architecture?
A Service Oriented Architecture (SOA) is not a single program or technology. Think of it, rather, as a software design paradigm.
As you may already know, a hardware bus is a physical connector that ties together multiple systems and subsystems. If you use one, instead of having a large number of point-to-point connectors between pairs of systems, you can simply connect each system to the central bus. An enterprise service bus (ESB) does exactly the same thing in software.
The ESB sits in the architectural layer above a messaging system. This messaging system facilitates asynchronous communications between services through the ESB. In fact, when you are using an ESB, everything is, conceptually, either a service (which, in this context, is your application software) or a message being sent between services. The services are listed as connection addresses (known as end-points references.)
It is important to note that, in this context, a "service" is not necessarily always a web service. Other types of applications, using such transports as File Transfer Protocol and the Java Message Service, can also be "services."
At this point, you may be wondering if an enterprise service bus is the same thing as a service-oriented architecture. The answer is, "Not exactly." An ESB does not form a service-oriented architecture of itself. Rather, it provides many of the tools than can be used to build one. In particular, it facilitates the loose-coupling and asynchronous message passing needed by a SOA. Always think of a SOA as being more than just software: it is a series of principles, patterns and best practices.
1.3. Key Points of a Service-Oriented Architecture
These are the key components of a service-oriented architecture:
- the messages being exchanged
- the agents that act as service requesters and providers
- the shared transport mechanisms that allow the messages to flow back and forth.
1.4. What is the JBoss Enterprise SOA Platform?
The JBoss Enterprise SOA Platform is a framework for developing enterprise application integration (EAI) and service-oriented architecture (SOA) solutions. It is made up of an enterprise service bus (JBoss ESB) and some business process automation infrastructure. It allows you to build, deploy, integrate and orchestrate business services.
1.5. The Service-Oriented Architecture Paradigm
The service-oriented architecture (SOA) consists of three roles: requester, provider, and broker.
- Service Provider
- A service provider allows access to services, creates a description of a service and publishes it to the service broker.
- Service Requester
- A service requester is responsible for discovering a service by searching through the service descriptions given by the service broker. A requester is also responsible for binding to services provided by the service provider.
- Service Broker
- A service broker hosts a registry of service descriptions. It is responsible for linking a requester to a service provider.
1.6. Core and Components
The JBoss Enterprise SOA Platform provides a comprehensive server for your data integration needs. On a basic level, it is capable of updating business rules and routing messages through an Enterprise Service Bus.
The heart of the JBoss Enterprise SOA Platform is the Enterprise Service Bus. JBoss (ESB) creates an environment for sending and receiving messages. It is able to apply “actions” to messages to transform them and route them between services.
There are a number of components that make up the JBoss Enterprise SOA Platform. Along with the ESB, there is a registry (jUDDI), transformation engine (Smooks), message queue (HornetQ) and BPEL engine (Riftsaw).
1.7. Components of the JBoss Enterprise SOA Platform
- A full Java EE-compliant application server (the JBoss Enterprise Application Platform)
- an enterprise service bus (JBoss ESB)
- a business process management system (jBPM)
- a business rules engine (JBoss Rules)
- support for the optional JBoss Enterprise Data Services (EDS) product.
1.8. JBoss Enterprise SOA Platform Features
- The JBoss Enterprise Service Bus (ESB)
- The ESB sends messages between services and transforms them so that they can be processed by different types of systems.
- Business Process Execution Language (BPEL)
- You can use web services to orchestrate business rules using this language. It is included with SOA for the simple execution of business process instructions.
- Java Universal Description, Discovery and Integration (jUDDI)
- This is the default service registry in SOA. It is where all the information pertaining to services on the ESB are stored.
- This transformation engine can be used in conjunction with SOA to process messages. It can also be used to split messages and send them to the correct destination.
- JBoss Rules
- This is the rules engine that is packaged with SOA. It can infer data from the messages it receives to determine which actions need to be performed.
1.9. Features of the JBoss Enterprise SOA Platform's JBossESB Component
The JBoss Enterprise SOA Platform's JBossESB component supports:
- Multiple transports and protocols
- A listener-action model (so that you can loosely-couple services together)
- Content-based routing (through the JBoss Rules engine, XPath, Regex and Smooks)
- Integration with the JBoss Business Process Manager (jBPM) in order to provide service orchestration functionality
- Integration with JBoss Rules in order to provide business rules development functionality.
- Integration with a BPEL engine.
Furthermore, the ESB allows you to integrate legacy systems in new deployments and have them communicate either synchronously or asynchronously.
In addition, the enterprise service bus provides an infrastructure and set of tools that can:
- Be configured to work with a wide variety of transport mechanisms (such as e-mail and JMS),
- Be used as a general-purpose object repository,
- Allow you to implement pluggable data transformation mechanisms,
- Support logging of interactions.
There are two trees within the source code:
org.jboss.soa.esb. Use the contents of the
org.jboss.internal.soa.esbpackage sparingly because they are subject to change without notice. By contrast, everything within the
org.jboss.soa.esbpackage is covered by Red Hat's deprecation policy.
1.10. Task Management
JBoss SOA simplifies tasks by designating tasks to be performed universally across all systems it affects. This means that the user does not have to configure the task to run separately on each terminal. Users can connect systems easily by using web services.
Businesses can save time and money by using JBoss SOA to delegate their transactions once across their networks instead of multiple times for each machine. This also decreases the chance of errors ocurring.
1.11. Integration Use Case
Acme Equity is a large financial service. The company possesses many databases and systems. Some are older, COBOL-based legacy systems and some are databases obtained through the acquisition of smaller companies in recent years. It is challenging and expensive to integrate these databases as business rules frequently change. The company wants to develop a new series of client-facing e-commerce websites, but these may not synchronise well with the existing systems as they currently stand.
The company wants an inexpensive solution but one that will adhere to the strict regulations and security requirements of the financial sector. What the company does not want to do is to have to write and maintain “glue code” to connect their legacy databases and systems.
The JBoss Enterprise SOA Platform was selected as a middleware layer to integrate these legacy systems with the new customer websites. It provides a bridge between front-end and back-end systems. Business rules implemented with the JBoss Enterprise SOA Platform can be updated quickly and easily.
As a result, older systems can now synchronise with newer ones due to the unifying methods of SOA. There are no bottlenecks, even with tens of thousands of transactions per month. Various integration types, such as XML, JMS and FTP, are used to move data between systems. Any one of a number of enterprise-standard messaging systems can be plugged into JBoss Enterprise SOA Platform providing further flexibility.
An additional benefit is that the system can now be scaled upwards easily as more servers and databases are added to the existing infrastructure.
1.12. Utilising the JBoss Enterprise SOA Platform in a Business Environment
Cost reduction can be achieved due to the implementation of services that can quickly communicate with each other with less chance of error messages occurring. Through enhanced productivity and sourcing options, ongoing costs can be reduced.
Information and business processes can be shared faster because of the increased connectivity. This is enhanced by web services, which can be used to connect clients easily.
Legacy systems can be used in conjunction with the web services to allow different systems to "speak" the same language. This reduces the amount of upgrades and custom code required to make systems synchronise.