In the architectural model of enterprise software, we mainly discuss SOA and microservice architecture.
The full name of SOA is Service-Oriented Architecture, which can be translated as "service-oriented architecture". It is a component model that links different functional units (called services) of an application through well-defined interfaces and contracts between these services. . An interface is defined in a neutral way, and it should be independent of the hardware platform, operating system, and programming language that implements the service. This allows services built in a wide variety of systems to interact in a unified and common way.
SOA is a coarse-grained, loosely coupled service architecture. Services communicate through simple and precisely defined interfaces, without involving underlying programming interfaces and communication models. SOA can be seen as a natural extension of the B/S model, XML ( a subset of the standard general-purpose markup language )/Web Service technology.
SOA services have platform-independent self-describing XML documents. Web Services Description Language (WSDL, Web Services Description Language) is a standard language for describing services.
SOA services communicate using messages, which are usually defined using XML Schema (also called XSD, XML Schema Definition). Communication between a consumer and a provider or between a consumer and a service is more common in an environment where the provider is not known. Communication between services can also be viewed as critical business documents handled within an enterprise.
Within an enterprise, SOA services are maintained through a registry that acts as a directory listing. An application looks for and invokes a service in the registry. Universal Description, Definition, and Integration (UDDI, Universal Description, Definition, and Integration) is a standard for service registration.
Each SOA service has a quality of service (QoS, quality of service) associated with it. Some of the key elements of QoS are security requirements (such as authentication and authorization), reliable communication, and policies on who can invoke the service.
To run and manage SOA applications, enterprises need SOA foundations, which are part of the SOA platform. The SOA foundation must support all relevant standards, and required runtime containers. The schematic diagram of SOA infrastructure is as follows:
In the above diagram, WSDL, UDDI and SOAP are the basic components of SOA foundation. WSDL is used to describe services; UDDI is used to register and look up services; and SOAP, as the transport layer, is used to transfer messages between consumers and service providers. SOAP is the default mechanism for web services. A consumer can look up the service in the UDDI registry, obtain the WSDL description of the service, and then invoke the service through SOAP.
The WS-I Basic Profile, provided by the Web Services Interoperability Organization, is the core component required for SOA service testing and interoperability. Service providers can use the Basic Profile test program to test the interoperability of services on different platforms and technologies.
Although J2EE and .NET platforms are commonly used platforms for developing SOA applications, SOA is not limited to this. Platforms like J2EE not only provide a platform for developers to naturally participate in SOA, but also introduce scalability, reliability, availability, and performance into the SOA world through their inherent characteristics. New specifications, such as JAXB (Java API for XML Binding), are used to locate XML documents to Java classes; JAXR (Java API for XML Registry) is used to standardize operations on UDDI registry (registry); Java API for XML- based Remote Procedure Call) is used to call remote services in J2EE1.4, which makes it easy to develop and deploy Web services that can be ported to standard J2EE containers, and at the same time, realize cross-platform (such as. NET) service interaction use. XML-RPC (