Service-oriented architecture (SOA) concepts and implementations

Abstract

This tutorial explains how to implement a Service-Oriented Architecture (SOA) for reliable systems using an Enterprise Service Bus (ESB) and the Ada Web Server (AWS). The first part of the tutorial describes terms of Service-Oriented Architectures (SOA) including service, service registry, service provider, service consumer, Service Oriented Architecture Protocol (SOAP), and Web Service Description Language (WSDL). This tutorial also presents principles of SOA including loose coupling, encapsulation, composability of web services, and statelessness of web services. The tutorial also covers the benefits of SOA and organizations that are supporting SOA infrastructure. The second part of the tutorial covers the Enterprise Service Bus (ESB) including definitions, capabilities, benefits and drawbacks. The tutorial discusses the difference between SOA and an ESB, as well as some of the commercially available ESB solutions on the market. The Mule ESB is explored in more detail and several examples are given. In the third part, the tutorial covers the Ada Web Server (AWS) built using the Ada programming language. The tutorial covers the capabilities of AWS and explains how to build and install AWS. The tutorial explains how to build an AWS server and include the server in an Ada application. The tutorial demonstrates how to build a call back function in AWS and build a response to a SOAP message. Finally, the tutorial explains how to connect an AWS server to an ESB endpoint. AWS is a key component to building a SOA for a reliable system. This capability allows the developer to expose services in a high-integrity system using the Ada and SPARK programming languages.