In an API-led connectivity approach, different APIs are layered to provide modular and reusable services. For an order processing API that coordinates stateful interactions with various microservices, the integration architect used the orchestration interaction composition pattern. Here’s a step-by-step explanation:

Understanding Orchestration:

Definition: Orchestration involves coordinating multiple services to achieve a complex business workflow. Unlike choreography, which relies on each service knowing its part, orchestration uses a central controller to manage the interactions.

Role of the Orchestrator: The orchestrator manages the execution sequence, handles the state, and ensures all the necessary steps are completed successfully.

Order Processing API:

API-Led Connectivity: An order processing API, following API-led connectivity, sits in the Process layer, handling complex business processes and logic.

Stateful Interactions: Orchestration is particularly suitable for stateful interactions where the process needs to remember the state between steps, such as validating an order, creating it, and fulfilling it.

Implementation Steps:

Microservices Interaction: The order processing API interacts with various microservices:

Validation Microservice: Checks the validity of the order details.

Creation Microservice: Creates the order in the system.

Fulfillment Microservice: Manages the order fulfillment process.

Coordination: The API orchestrates these steps, ensuring each one completes successfully before moving to the next, handling exceptions, and maintaining the state of the process.

References

MuleSoft Documentation: Orchestration Pattern

API-led Connectivity: MuleSoft API-led Connectivity