if there are 5 users calling the api at the same time or parallel then spring boot will create 5 threads for each user - spring boot

Question

here I want to ask about the concept of threads in spring boot. what I've read, if there are 5 api calls by 5 users simultaneously then spring boot will also automatically create 5 threads to respond to those 5 calls. or it will respond to the api call only with the main thread because we don't set spring boot using async thread. is it really like that? Thank you

Answer 1

Yes, that's the classic approach how requests are handled.

For example, when using the embedded Tomcat, you can define the maximum amount of threads to handle client requests: https://stackoverflow.com/a/25401832/2310221

That said, there are approaches that work differently, for example reactive programming with Spring Reactor :

Project Reactor is a fully non-blocking foundation with back-pressure support included