Research And Implementation Of Publish/subscribe Communication Mechanism

In the field of modern industrial control,there are more and more products which are similar in function while different in other ways. These products need communicate to each other frequently,while they have different API because they produced by different manufacturer, so they cann't communicate directly, each manufacturer have to develop special API to communicate to a particular product. To worse,these products more and more applied to distributed system with the development of computer technology. So how to make these products communicate in a convenient and efficient way in distributed system become a research focus.On the basis of discuss several solutions to the communicate problem, this paper main research Publish/Subscribe communication mode. This mode realized completely decouple in terms of time, space and synchronization relationship, which made it to a good choice for modern distribute compute environment.Firstly, after elaborated the problem of interoperability,this paper analyzed and compared three solutions to this problem, which are CORBA,OPC and Publish/Subscribe mode. Because Publish/Subscribe mode support many-to-many communication, which make it have higher communication efficiency and wider application range compared to the remaining two. And with the research and development of Real-Time Publish/Subscribe(RTPS) mode, it will play a greater role in Real-Time field. While CORBA and OPC have difficulty in Real-Time extending, which restrict its development in Real-Time field.Secondly, the paper deeply analyzed the two protocol of RTPS, discussed its auto-discovery and Real-Time mechanism. After described the principle of middleware and its product type,the paper elaborated the implementation of a Publish/Subscribe message-oriented middleware (MOM), which realized the main function of MOM.Finally, the paper created the Publish/Subscribe experimental model on the basis of queuing theory and use modeling language provided by PRISM simulated the model. On that basis, message recevie rate and message response time of Publish/Subscribe mode are tested through the rewards structure of PRISM.