SOA

 What Is SOA?

 SOA – Service-oriented Architecture – is an architecture style. Think of it as a catalog of architectural concepts or as a programming model. In an SOA architecture, all functions are provided as services assembled through an Enterprise Service Bus (ESB). This offers an unprecedented level of flexibility in deploying and reusing services.
                            
When you implement SOA, existing information systems are seen as services providing business functions. These functions are easily integrated because they provide clearly defined interfaces and can be accessed via standard transport protocols.

Two fundamental SOA elements are:

• Interoperability, which concerns business services, such as entering a command (which any Internet buyer has already used). Users must be able to communicate easily with the company’s outside Internet provider.
• Re-use, particularly important for small, frequently consumed singular services such as a calculation, a database rule, access verification, LDAP access, etc. These elements remain relatively internal to the company, but are used by a number of “local” business services. Some of these services, such as user management, can make up an infrastructure service layer.

Why Migrate to an SOA ?

SOA is a logical evolution for existing Web architectures. What makes it new and original is that it considers existing applications. Existing applications can be extremely wide-ranging, and users want to take advantage of what they already have.

The Enterprise Bus, or ability to make applications communicate with each other in a standardized way, is particularly attractive because it develops application interoperability. Standardization is the wave of the future.

Imagine you welcome a new partner into your organization. You can hook up your billing systems almost instantaneously, and the efficiency gains for your organization will be immediately obvious. Imagine integrating new CRM software. It uses Web Services to plug itself into existing management elements. The results are no more double entries, no more interface program development, and overall information system coherence with minimal effort.

ETL/EAI tools have already shown the way in this field. However, SOA goes much further--rather than transferring/transforming data from one system to another, SOA connects processes. The challenge is to make your IT communicate. With standardization of network communications, where TCP/IP completely dominates the entire planet, it is time for applications to standardize access to the services they provide.

SOA and the System i

To migrate an IBM i to SOA, the essential first step is to use ILE (Integrated Language Environment). Only ILE allows implementation of the basic principle of SOA: code modularity. Only ILE will let you mix native RPG or COBOL with Web technologies.
What’s more, you can convert any ILE program into a Web service in the WDSc environment. Once your business functions are developed, it is simple to make them Web accessible.

Where do we begin?

How can you migrate to SOA when your information is primarily made up of large applications that are not easily opened up to the outside? We strongly advise our clients to start with a specific functional project with quick benefits. For example, you may want to enter a new client’s information via the Web. You can make this function available to users through a Web site, and then simultaneously feed all the projects that need it. You will need to isolate all the new client entry functions and transform them into a single Web service. It is vital to have a specific project to integrate the specific technical characteristics of an SOA and redefine your programming standards.

The ARCAD team can provide you with the technical expertise you will need to get your foot in the door. For more information, refer to the Services page on our Website.

SOA and ARCAD Software Suites

There are three ARCAD tools to help businesses integrate SOA:

• The ARCAD-Open Repository is an in-depth knowledge base of the existing IS. This is where the system's legacy and change memory is located.
• ARCAD-Observer is involved in maintenance and transfer procedures for technical knowledge of the existing IS.
• ARCAD-Skipper allows easier integration of the new technology needed to establish SOA.

ARCAD Open Repository

A central repository is indispensable for any SOA project. Code modularity automatically means an increase in new components – and not all of these components work on the same platforms. The ARCAD repository allows references any component type, whether on an IBM i or deployed on a server, and whether you are handling components from IBM i, UNIX, Linux, or Windows.

The ARCAD Repository also collects all inter-component relationships (or cross-references, as developers call them). It is an essential information source to maintain control of application development.

The ARCAD-Observer Suite

Naturally, the initial step of an SOA procedure is to analyze the existing system. You will need to inventory the functions already contained within your IS that can be transformed into services.

ARCAD-Observer offers a battery of varied tools that let you delve into applications’ internal architecture to understand all the links. You can then reconstitute a data model, which is a fundamental basis from which you will work back through procedures to isolate management rules.

ARCAD-Observer automatically reconstitutes calling program cascades using calling chains. Each field can be followed from component to component, all the way into the source code. The source code analyzer then helps you present the internal logic of all your programs. At a higher level, you can use the macroscopic views to get a broader picture of your IS’s major functional areas.

The ARCAD-Skipper Suite

Combined with the ARCAD repository, ARCAD-Skipper allows rigorous, coherent organization of all software component change processes, regardless of their original platform. The biggest advantage is its ability to deploy components onto diverse servers using a single process. In addition to these traditional functions, ARCAD-Skipper painlessly integrates new development technologies. Skipper particularly focuses on the two bases of SOA: ILE and SQL.