Clarification on Threading and Reactive vs. MVC Setup

[v-nafiseh]

Hi,
I’m using this project as part of my research and running load tests to analyze performance. I need a full understanding of the threading and server configuration to ensure my results are accurate. I have the following questions:

• Based on the dependencies, it seems this application uses Spring MVC with Tomcat (via spring-boot-starter-web). However, there are logs suggesting WebFlux-related configurations (e.g., WebFluxSecurity, WebFluxAutoConfiguration). Can you confirm whether the application is running Tomcat or Netty by default?
• Regarding threading, I noticed applicationTaskExecutor metrics in the actuator. Is this TaskExecutor used for async tasks only, or does it also handle HTTP request threads?
• To adjust thread pool sizes for handling HTTP requests, where should I configure the settings? Is it in the application properties, or elsewhere in the codebase?

I would really appreciate your help!

[arey]

Hi @v-nafiseh

Thanks for using the Discussions tab of the Spring Petclinic microservices project, it is the right place.
We have different microservices. Each could use its own stack.

The api-gateway microservice uses Spring Boot Gateway. Its spring-cloud-starter-gateway starter depends on the spring-boot-starter-webflux which uses the reactive stack (reactor and netty). Jetty is used as the web container.

The other microservices use a non-reactive stack. Tomcat is used as the web container.
Java 21 virtual threading is not enabled in this project. So Tomcat uses physical threads.
The default Spring Boot configuration has not been customised by setting the server.tomcat.threads.max property. This allowed a maximum of 200 worker threads to be used by Tomcat.

I hope I've answered your questions

Antoine