Criteria Arguing for a New Microservice Instead of Extending an Existing One
The criteria for deciding on when to start a new microservice include the following:
- 1. Introduction of different data models and data (domain versus process data)
- 2. Mixing of synchronous and asynchronous data processing
- 3. Incorporation of additional services
- 4. Different load scenarios for different aspects within one service
The example of the registration service could be further extended: the verification of the customer’s street address could also be performed by an external provider. This is common in order to ensure the existence of the denoted address. Another scenario is the manual clearance of a customer in case of double registration. The incorporation of a solvency check or customer scoring upon registration likewise are frequent scenarios.
All these domain-based aspects belong in principle to the customer registration and tempt developers and architects to integrate the corresponding requirements into the existing microservice. As a result the microservice grows into more than just one microservice.