Chapter 1. Microservices at a glance
Figure 1.1. The Receive Stock microservice exposes an API to be used when new stock arrives. Other microservices can call that API.
Figure 1.2. Other microservices continue to run while the Shopping Cart microservice is being deployed.
Figure 1.3. Running more than one microservice within a process leads to high coupling.
Figure 1.4. One microservice can’t access another’s data store.
Figure 1.5. When front-end code makes a request to add an item to the shopping cart, it only communicates with the API Gateway microservice. What goes on behind the gateway isn’t visible.
Figure 1.6. The API Gateway microservice is all the client sees, but it’s a thin layer in front of a system of microservices. The arrows indicate calls between different parts of the system, and the numbers on the arrows show the sequence of calls.
Figure 1.7. The Shopping Cart microservice publishes events, and other subscribing microservices react.
Figure 1.8. When a user adds an item to their shopping cart, the front end makes a request to the API Gateway microservice, which collaborates with other microservices to fulfill the request. During processing, microservices may raise events that other microservices can subscribe to and handle asynchronously.