Design And Implementation Of Business Process Orchestration Engine

With the development of workflow engines and workflow automation software,paper-based workflows have been replaced by electronic workflows based on various software.Many software systems introduce custom process engines to enable their own software ecosystem,but there are no unified process standards.Workflows between different software are not interoperable,and each different workflow engine has its own design and implementation for workflows.This has resulted in workflows that can only be shared and used within a limited software range.In addition,the current workflow engine is still lacking in the access of custom processes and external services,and it cannot access custom external services and choreograph more complex processes.Aiming at the shortcomings of workflow engines,this thesis designs and implements a business workflow engine with a wider range of application scenarios based on the Serverless Workflow definition specification of the Cloud Native Computing Foundation(CNCF).This thesis divides the business workflows orchestration engine into four modules: the workflow executor,workflow management,external resource resolution and invocation,and basic system.The executor is responsible for parsing the workflow definition,calling different types of workflows,processing different workflow states,including calling interfaces defined in compliance with the Open API specification,performing remote calls defined in compliance with g RPC,performing dynamic expression calculation,waiting for and receiving events defined in compliance with Cloud Events,sharing,injecting,filtering,and passing workflow context.The event management module is responsible for managing the events required in the workflow.The workflow management module is responsible for managing the core workflow definition,searching and injecting event and external resource definitions that need to be consumed or produced,and managing workflow metadata such as grouping information and version information.External resource management is mainly used for unified definition,parsing,and cache reuse of standards such as Open API.Basic system functions include user management,permission,and access control.Business process orchestration engine adopts the idea of domain driven design to grasp the whole design and implementation of the system.Technical aspects are developed using the Spring Boot framework.The data storage aspect uses Mongo DB to manage the various definitions involved in the process.Caching Caffeine speeds up the resolution and use of external resources.Access control Use Casbin to achieve RESTful and RBAC access control.This thesis designs and implements a lightweight and unified business process orchestration engine.It improves the reusability of processes,supports standardized external service references,expands the applicability scope of processes,and has practical significance.