title: WebFlux Spring Boot @Transactional with reactive MongoDB
body: <p>Does WebFlux Spring Boot <code>@Transactional</code> annotation work with reactive MongoDB?</p>
  <p>I use WebFlux Spring Boot with reactive MongoDB like:</p>
  <pre><code>    id 'org.springframework.boot' version '2.6.7'
      ...
      implementation 'org.springframework.boot:spring-boot-starter-webflux'
      implementation 'org.springframework.boot:spring-boot-starter-data-mongodb-reactive'
      ...
  </code></pre>
  <p>I marked one of my method <code>@Transactional</code> to test. But it seems the annotation does not work for me. If an error occurs inside this method, then it still adds a raw to my mongoDB database.</p>
  <pre><code>      import org.springframework.transaction.annotation.Transactional;
  
        ...
  
        @Transactional
        public Mono&lt;Chat&gt; createChat(Chat chat) {
          return chatRepository
              .save(chat)
              .map(
                  c-&gt; {
                    if (true) {
                      throw new RuntimeException();
                    }
                    return c;
                  });
        }
  </code></pre>
  <p>Do I miss something or Spring Boot <code>@Transactional</code> annotation does not work with reactive MongoDB?</p>
  <p>I use MongoDB v5.0.8</p>