concept Delivery Service in category microservice

This is an excerpt from Manning's book Microservices Patterns. Login to get full access to this book.

Delivery Service— Manages delivery of orders from restaurants to consumers

I begin this chapter by describing the motivations for refactoring a monolith to a microservice architecture. I then describe how to develop the strangler application by implementing new functionality as services and extracting services from the monolith. Next, I cover various design topics, including how to integrate the monolith and services, how to maintain database consistency across the monolith and services, and how to handle security. I end the chapter by describing a couple of example services. One service is Delayed Order Service, which implements brand new functionality. The other service is Delivery Service, which is extracted from the monolith. Let’s start by taking a look at the concept of refactoring to a microservice architecture.

The FTGO monolith needs to invoke Delivery Service to manage deliveries. The monolith also needs to exchange data with Delivery Service. This collaboration is enabled by the integration glue. Figure 13.20 shows the design of the Delivery Service integration glue. Delivery Service has a delivery management API. It also publishes Delivery and Courier domain events. The FTGO monolith publishes Courier domain events.

Figure 13.20. The design of the Delivery Service integration glue. Delivery Service has a delivery management API. The service and the FTGO monolith synchronize data by exchanging domain events.

Let’s look at the design of each part of the integration glue, starting with Delivery Service’s API for managing deliveries.