title: Why spring-webflux application is running on tomcat as default, instead of netty?
body: <p>I created a Spring-webflux project using below <code>pom.xml</code> but when I am starting the application, it's starting on Tomcat. Shouldn't it start default on Netty?</p>
  <pre><code>&lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot;?&gt;
  &lt;project xmlns=&quot;http://maven.apache.org/POM/4.0.0&quot; xmlns:xsi=&quot;http://www.w3.org/2001/XMLSchema-instance&quot;
           xsi:schemaLocation=&quot;http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd&quot;&gt;
      &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;
      &lt;parent&gt;
          &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
          &lt;artifactId&gt;spring-boot-starter-parent&lt;/artifactId&gt;
          &lt;version&gt;2.3.5.RELEASE&lt;/version&gt;
      &lt;/parent&gt;
      &lt;groupId&gt;com.test&lt;/groupId&gt;
      &lt;artifactId&gt;reactive-rest&lt;/artifactId&gt;
      &lt;version&gt;0.0.1-SNAPSHOT&lt;/version&gt;
      &lt;name&gt;reactive-rest&lt;/name&gt;
  
      &lt;properties&gt;
          &lt;java-version&gt;1.8&lt;/java-version&gt;
      &lt;/properties&gt;
  
      &lt;dependencies&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
              &lt;artifactId&gt;spring-boot-starter-data-r2dbc&lt;/artifactId&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
              &lt;artifactId&gt;spring-boot-starter-rsocket&lt;/artifactId&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
              &lt;artifactId&gt;spring-boot-starter-security&lt;/artifactId&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
              &lt;artifactId&gt;spring-boot-starter-webflux&lt;/artifactId&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
              &lt;artifactId&gt;spring-boot-starter-websocket&lt;/artifactId&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.springframework.security&lt;/groupId&gt;
              &lt;artifactId&gt;spring-security-messaging&lt;/artifactId&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.springframework.security&lt;/groupId&gt;
              &lt;artifactId&gt;spring-security-rsocket&lt;/artifactId&gt;
          &lt;/dependency&gt;
  
          &lt;dependency&gt;
              &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
              &lt;artifactId&gt;spring-boot-devtools&lt;/artifactId&gt;
              &lt;scope&gt;runtime&lt;/scope&gt;
              &lt;optional&gt;true&lt;/optional&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
              &lt;artifactId&gt;spring-boot-configuration-processor&lt;/artifactId&gt;
              &lt;optional&gt;true&lt;/optional&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.projectlombok&lt;/groupId&gt;
              &lt;artifactId&gt;lombok&lt;/artifactId&gt;
              &lt;optional&gt;true&lt;/optional&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
              &lt;artifactId&gt;spring-boot-starter-test&lt;/artifactId&gt;
              &lt;scope&gt;test&lt;/scope&gt;
              &lt;exclusions&gt;
                  &lt;exclusion&gt;
                      &lt;groupId&gt;org.junit.vintage&lt;/groupId&gt;
                      &lt;artifactId&gt;junit-vintage-engine&lt;/artifactId&gt;
                  &lt;/exclusion&gt;
              &lt;/exclusions&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;io.projectreactor&lt;/groupId&gt;
              &lt;artifactId&gt;reactor-test&lt;/artifactId&gt;
              &lt;scope&gt;test&lt;/scope&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.springframework.security&lt;/groupId&gt;
              &lt;artifactId&gt;spring-security-test&lt;/artifactId&gt;
              &lt;scope&gt;test&lt;/scope&gt;
          &lt;/dependency&gt;
      &lt;/dependencies&gt;
  
      &lt;build&gt;
          &lt;plugins&gt;
              &lt;plugin&gt;
                  &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
                  &lt;artifactId&gt;spring-boot-maven-plugin&lt;/artifactId&gt;
              &lt;/plugin&gt;
              &lt;plugin&gt;
                  &lt;groupId&gt;org.apache.maven.plugins&lt;/groupId&gt;
                  &lt;artifactId&gt;maven-surefire-plugin&lt;/artifactId&gt;
              &lt;/plugin&gt;
              &lt;plugin&gt;
                  &lt;groupId&gt;org.apache.maven.plugins&lt;/groupId&gt;
                  &lt;artifactId&gt;maven-compiler-plugin&lt;/artifactId&gt;
              &lt;/plugin&gt;
          &lt;/plugins&gt;
          &lt;pluginManagement&gt;
              &lt;plugins&gt;
                  &lt;plugin&gt;
                      &lt;groupId&gt;org.apache.maven.plugins&lt;/groupId&gt;
                      &lt;artifactId&gt;maven-compiler-plugin&lt;/artifactId&gt;
                      &lt;configuration&gt;
                          &lt;source&gt;${java-version}&lt;/source&gt;
                          &lt;target&gt;${java-version}&lt;/target&gt;
                      &lt;/configuration&gt;
                  &lt;/plugin&gt;
              &lt;/plugins&gt;
          &lt;/pluginManagement&gt;
      &lt;/build&gt;
  
  &lt;/project&gt;
  
  </code></pre>
  <p>The main class:</p>
  <pre><code>@SpringBootApplication(exclude = {SecurityAutoConfiguration.class, WebMvcAutoConfiguration.class})
  public class ReactiveRestApplication {
  
      public static void main(String[] args) {
          SpringApplication.run(ReactiveRestApplication.class, args);
      }
  
  }
  </code></pre>
  <p>Start logs:</p>
  <pre><code>2020-11-09 18:29:26.311  INFO 80838 --- [  restartedMain] o.s.b.d.a.OptionalLiveReloadServer       : LiveReload server is running on port 35729
  2020-11-09 18:29:26.375  INFO 80838 --- [  restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
  2020-11-09 18:29:26.390  INFO 80838 --- [  restartedMain] c.o.r.ReactiveRestApplication            : Started ReactiveRestApplication in 18.256 seconds (JVM running for 25.2)
  
  </code></pre>
  <p>I even tried removing tomcat dependency but still the application starts on Tomcat</p>
  <pre><code>        &lt;dependency&gt;
              &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
              &lt;artifactId&gt;spring-boot-starter-webflux&lt;/artifactId&gt;
              &lt;exclusions&gt;
                  &lt;exclusion&gt;
                      &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
                      &lt;artifactId&gt;spring-boot-starter-tomcat&lt;/artifactId&gt;
                  &lt;/exclusion&gt;
              &lt;/exclusions&gt;
          &lt;/dependency&gt;
  </code></pre>
  <p>Even tried setting <code>spring.main.web-application-type: reactive</code> but still tomcat.</p>
  <p>Update: I kept only <code>spring-boot-starter-webflux</code> and removed every other dependency. This time also service started on 'Tomcat'</p>