Food to Go is a fictitious, on-demand logistics company that delivers takeout orders from restaurants to customers. A key part of the application is the restaurant management service, which maintains a database of restaurants that can be queried for availability to deliver an order to a customer at a particular time. This version of the restaurant management service has an architecture based on microservices, event sourcing and Command Query Responsibility Segregation (CQRS). It is written in Java and uses the Eventuate Platform, Spring Boot, and Redis.
Don't forget to take a look at the other Eventuate example applications.
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The following diagram shows the architecture of the application.
The application is built using CQRS. The command side service handles creates, updates and deletes. It defines the following REST endpoints:
- POST /restaurant - create a restaurant
- PUT /restaurant/id - update a restaurant
- DELETE /restaurant/id - delete a restaurant
The command side service stores restaurants in the Eventuate event store.
The query side service handles GET requests. It subscribes to Restaurant events and maintains a denormalized representation of the restaurants in Redis for fast querying. The query side service defines the following REST endpoints:
- GET /restaurant/id - finds a restaurant
- GET /availablerestaurants?zipcode=xx&dayOfWeek=xx&hour=xx&minute=xx - finds restaurants that are available to deliver to the specified zip code at the specified time
The application is built using Eventuate, which is an application platform for writing transactional microservices. It provides a simple yet powerful event-driven programming model that is based on event sourcing and Command Query Responsibility Segregation (CQRS). Eventuate solves the distributed data management problems inherent in a microservice architecture. It consists of a scalable, distributed event store and client libraries for various languages and frameworks including Java, Scala, and the Spring framework.
There are two versions of Eventuate:
- Eventuate SaaS server - this is a full featured event store that is hosted on AWS
- Eventuate Local - an open-source event store that is built using MySQL and Kafka
This is a Java 8, Gradle project. However, you do not need to install Gradle since it will be downloaded automatically. You just need to have Java 8 installed.
The details of how to build and run the services depend slightly on whether you are using Eventuate SaaS or Eventuate Local.
First, must sign up to get your credentials in order to get free access to the SaaS version.
Next, build the application:
./gradlew assemble
Next, you can launch the application using Docker Compose
docker-compose up -d
First, build the application:
./gradlew assemble -P eventuateDriver=local
Next, you can launch the application using Docker Compose
export DOCKER_HOST_IP=...
docker-compose -f docker-compose-eventuate-local.yml up -d
Note: You need to set DOCKER_HOST_IP
before running Docker Compose.
DOCKER_HOST_IP
is the IP address of the machine running the Docker daemon.
It must be an IP address or resolvable hostname.
It cannot be localhost
.
See this guide to setting DOCKER_HOST_IP
for more information.
Finally, you can use the Swagger UI provided by the services to create, update, delete and view restaurants:
http://${DOCKER_HOST_IP?}:8081/swagger-ui.html
- Restaurant command-side servicehttp://${DOCKER_HOST_IP?}:8082/swagger-ui.html
- Restaurant query-side service
Note: DOCKER_HOST_IP is the IP address of the machine running the Docker daemon.
(Hint: best to open these URLs in separate tabs)
Don't hesitate to create an issue or see