Default number of threads in Spring boot 2.0 reactive webflux configuration

The default number of threads for request handling is determined by the underlying web server; by default, Spring Boot 2.0 is using Reactor Netty, which is using Netty's defaults (check out the EventLoopGroup documentation for that).

Spring Boot will soon allow you to customize that part (see #10418). In the meantime, you can provide your own ReactiveWebServerFactory bean and change that through the HttpServer configuration options (see this comment).

Currently, it seems that Spring Webflux 2.0 does not provide the ability to control threads.

Spring Webflux 2.0 is using Reactor-Netty. And ReactorNettyclass provides some configurations.

• reactor.netty.ioWorkerCount
• reactor.netty.ioSelectCount
• reactor.netty.pool.maxConnections
• etc

So, You can use it like this.

System.setProperty("reactor.netty.ioWorkerCount", "100");

I hope that Spring Boot will provide a custom configuration.