[Entry series] SOA technology

SOA itself is an abstract concept of how to organize software together. It relies on more specific concepts and technologies that are implemented using XML and web services and exist in the form of software. In addition, it also requires security, policy management, reliable message delivery, and support from the accounting system to work effectively. You can also further improve it through distributed transaction processing and distributed software status management.

The difference between SOA services and web services lies in design. The SOA concept does not define exactly how services interact, but just how services understand and interact. The difference is the difference between the strategy that defines how to execute the process and the tactics that execute the process. On the other hand, there are specific guiding principles for Web Services to transmit messages between services that require interaction. Tactically, implementing the SOA model is the most common SOA model for soap messages transmitted through HTTP. Therefore, in essence, web is one of the specific ways to implement SOA.

Although we feel that Web services are the best way to implement SOA, SOA is not limited to Web Services. Other protocols that use WSDL to directly implement service interfaces and communicate through XML messages can also be included in SOA. As pointed out elsewhere, the MQ systems of CORBA and IBM can also participate in SOA by using new features that can process WSDL. If two services need to exchange data, they also need to use the same message transmission protocol, but the data interface allows the same information exchange.

A new software object is added to the framework of the SOA architecture to establish proper control of all such information, as well as application security, policy, reliability, and accounting requirements. This object is the Enterprise Service Bus (ESB). It uses many possible message passing protocols for proper control and transmission of streams or even all messages between services. Although ESB is not absolutely necessary, it is essential to correctly manage your business processes in SOA. The ESB itself can be a single engine, or even a distributed system composed of many same-level and lower-level ESB, which work together to maintain the running of the SOA system. In terms of concept, it evolved from the storage and forwarding mechanism established by computer science concepts such as message queue and distributed transaction computing.

From the perspective of developers, the tools they use must be aware of the capabilities of SOA and allow developers to effectively use SOA objects. This includes the process of designing an SOA model, developing services and service objects, and testing SOA applications to form a whole. Therefore, developers must be prepared for service-oriented application design/Development (Soad.