In a distributed architectures (like microservices or event-driven architecture) sometimes a client request requires information from more than one service and this is called workflow management. There are primarly two types: orchestration and choreography.
Orchestration
Orchestration means that there is one service (conductor) which takes care of the workflow process.
Pros of Orchestration
- Error handling is easy
- Easy to understand – centralized workflow
- Easy workflow state management
- Easy to change workflow steps
Cons of Orchestration
- Performance – a lot of round trips
- Tight couping between orchestrator and orchestra
- If orchestractor goes down, nothing can work anymore (availability)
Choreography
Choreography means that services (dancers) know exactly what to do – no managing service (conductor) needed.
Pros of Choreography
- Responsivness and performance – no bottlenecks
- Loose coupling (at least not as tight as for Orchestrator)
Cons of Choreography
- Difficult error handling due to distributed workflow
- Difficult state management due to distributed workflow
- Difficult recoverability due to distributed workflow