Question
I am developing application server using spring boot app but now I want to know what is the default maximum (client request) thread pool size in spring and how can I customize that value?
Answer
Assuming that you're using embedded Tomcat, Spring Boot provides a property to
control the size of the client request thread pool. Its default value is zero
which leaves Tomcat to use its default of 200. If you're using Spring Boot 2.3
or later, this property is named
[server.tomcat.threads.max](https://docs.spring.io/spring-
boot/docs/2.7.x/reference/html/application-properties.html#application-
properties.server.server.tomcat.threads.max). In earlier versions of Spring
Boot, the property is named [server.tomcat.max- threads](https://docs.spring.io/spring-
boot/docs/2.2.x/reference/html/appendix-application-properties.html#common-
application-properties-server).
To customise the size of this thread pool you should specify a non-zero value
for the property in your application.properties or application.yml file.
