example-spring-boot-2.x-service

A simple Spring-boot 2.X service to compare with various backend technologies.

Blog post: comparing execution model of various backend technologies

A single endpoint which retrieves data from a Mongo

curl -X GET http://localhost:8080/books

Stack:

• Spring Boot 2.X
• Spring WebFlux
• Reactive Spring Data - Mongo

Setup Mongo

You can use the embedded Mongo buy uncommenting de.flapdoodle.embed the dependency in the pom.xml.

You can also easily setup a local Mongo running from a local Docker image. Pull the Mongo image and run remembering to use the -p option to the port. e.g:

docker run -p 27017:27017 --name some-mongo mongo

Spring Boot 2.X features

• event-loop execution model:
  • asynchronous and non-blocking IO
  • thread pool can be smaller than Spring Boot 1.5.X
  • see previous commits for the migration and how the threading model changes
    • Spring MVC + Reactive Spring Data, mixed model, Spring will marshal between threads
    • Spring WebFlux + Reactive Spring Data, completely none-blocking
• Reactive stack:
  • Spring WebFlux (non-blocking reactive alternative web framework to Spring MVC. uses Netty by default)
  • Reactive Spring Data (where the DB supports e.g. spring-boot-starter-data-mongodb-reactive)
  • Netty, Servlet 3.1 (async runtime)
• notes:
  • support for Reactive Streams API
  • motivation is scalability
  • relational DBs currently cannot be reactive
  • JPA currently only blocking
  • interesting reading on applicability of webFlux or MVC, many situations precludes using it.

fig.1 Spring MVC + Reactive Spring Data : mixed model

fig.2 webFlux (controllers API) + Reactive Spring Data : fully reactive