SOA Service Oriented Architecture

        SOA It's a service-oriented architecture , That is, the IT The system is composed of services , That is, each application system of the enterprise consists of many standard service parts “ assemble ” Get up , There is a very loose coupling relationship between the services in the application system .

        Gartner The company in 1996 In, it was further proposed that SOA The concept of , Service oriented architecture , It is essentially a service-oriented idea in the enterprise IT Application of architecture . Service oriented thinking , It is a new thought pattern after the object-oriented thought , Its core feature is the loose coupling 、 Coarse grained service units to build software . As a thought ,SOA It does not involve any specific implementation technical details , But the idea will bring social benefits after all .

         It was found that , Enterprise service bus （ Referred to as ESB） It's the realization of SOA One of the main technologies of , therefore ESB It becomes SOA Core technology foundation of . Of course , no need ESB Nor can it be said that your system is not SOA, For example, the popular microservices are SOA A concrete realization of , It uses containers to package services .SOA The core task of the product is to manage the service units in the enterprise , Specific tasks can be broken down into ： Registration of service units 、 Call of service unit 、 Operation of service unit 、 Deployment of service units 、 User management interface , And security control .

The main difference between services and modules is ： The module is equivalent to the spare parts of the automobile engine , The service is equivalent to the engine itself , The engine can run independently , Not the parts

Service is stateless , That is, the service itself does not change before and after being called , And the same service can run on multiple computers at the same time , This makes it easy to implement high availability computing and load balancing clusters , Schematic diagram 1 Shown ：

chart 1 SOA

Finally we can imagine , There are various standard services running on many servers in the enterprise , Many application systems correspond to their respective service invocation relationship description tables ,“ assemble ” An application software can be quickly and easily completed by a company clerk .

         In the cloud , Due to the wide range of applications and being operated by one company , Therefore, cloud operation companies adopt SOA The best place . Can be estimated , stay Cloud computing Time ,SOA Will be widely used . In the industry , Others believe that cloud computing will be SOA The terminator of , This view confuses different levels of things , Cloud computing is not a new technology or idea , It is just a model for people to use computing resources , and SOA Is a new software architecture idea .

ESB It's the realization of SOA One of the main technologies of ,SOA It is one of the important ideas for building a large cloud .SOA The concept of has been put forward for more than ten years , Before, it was difficult to take root in traditional enterprises , The fundamental reason is that various software systems of an enterprise are often developed by different software companies , And these software companies have a competitive relationship , act of one 's own free will , It is difficult to launch a consistent product that conforms to SOA Standard generic solutions .