Command Message: Driving Actions Across Systems
A Command Message encapsulates a request for action into a message format, which is then sent to the responsible service or application for execution. This pattern enables asynchronous command execution and decouples the command initiation from its execution.
Use Cases
- Operational Commands: Triggering specific operations in remote services, such as starting a batch job or updating a record.
- Workflow Management: Initiating and controlling the flow of a multi-step business process across various services.
How
Define a standardized command message format that includes an identifier, command type, and the necessary parameters for command execution. Use a messaging system to route these command messages to the appropriate service, which interprets and executes the command.
Benefits
- Decoupling: The sender of a command does not need to know about the receiver’s implementation details.
- Scalability: Command handlers can be scaled independently to handle varying loads.
- Flexibility: New commands can be added with minimal impact on existing services.
Potential Pitfalls
- Error Handling: Requires robust error handling to manage command failures gracefully.
- Complexity: Implementing a system that can handle a wide variety of commands can introduce complexity.