| In the environment of the Internet of things,the events generated by physical device need to be pushed to the responsive services in time,and the handle of the events may involve several different service collaboration.At this time,the cooperation between services should be ensure in a timely and orderly manner.Moreover,the geographical distribution of physical devices is more dispersed,Some of the services with high real-time requirements need to be deployed close to physical devices,and decentralized services are difficult to manage effectively.In this paper,by comparing the present distributed service system,proposes innovatively to integrate event-driven features into the process of service construction,and solves the problem of efficient and orderly collaboration between services.Through the construction of distributed service runtime environment,effective management and monitoring of distributed services are carried out.The generation of service is divided into two levels:atomic service and combination service.In the atomic service generation level,the Actor model is used to build the event response logic within the service.The service description method is improved,which enables it to describe the service with event driven characteristics,and generates the framework code with event response characteristics based on service description.At the service composition level,the service composition is integrated into the process modeling process,where the EPC model is used as an event driven modeling standard to ensure orderly collaboration of services.First,build a process editor for the EPC model.Then,build the syntax check function of the process model in the editor.Finally,the specific service binding is carried out in the modeling process to provide the basis for the service coordinator management of distributed service runtime agent.For efficient management of decentralized services,First,the split operation is performed to the already built process model,and the relation between the function and the event is extracted.Secondly,the partitioned functions are divided into different agents to be managed according to the difference in the service domain.The agent subscribes to the publish subscribe system the event topic within its own service domain,and the specific event message is sent to the service by the agent.Through the previous segmentation operation,the corresponding relation of event function is obtained to coordinate service calls in the service domain.Finally,the operation of the process is managed and monitored.The service of the management center can not only accept the status information sent by the agent,but also send the information of the control flow to the agent.Through this design,the distributed service can be efficiently monitored and managed.This paper describes the functional requirements,design principles and system implementation of event driven distributed service system,and validates the availability of the system through system testing. |
