title: Spring Integration : Publish Subscribe channel. Is it asynchronous?
body: <p>I am using a publish-subscribe channel after the inbound gateway receives a String message to parallely send it to the logger to log the message and to a transformer to transform the message. I want both these acivities to happen in parallel. </p>
  
  <p>My question is very simple - Does the publish subscribe channel in spring integration sends messages to it's subscibers parallely? </p>
  
  <p>Below is the code snippet from the source of spring-integration-context.xml.</p>
  
  <pre><code>&lt;int:gateway id="gateway" service-interface="com.test.Gateway"&gt;
      &lt;/int:gateway&gt;
  &lt;int:publish-subscribe-channel id="publishsubscribechannel" /&gt;
  
  &lt;int:service-activator input-channel="publishsubscribechannel"
          method="transformEvent" ref="transformer" output-channel="transformerreplychannel"&gt;
  &lt;/int:service-activator&gt;
  &lt;int:service-activator input-channel="publishsubscribechannel"
          method="logMessage" ref="logger"&gt;
  &lt;/int:service-activator&gt;
  </code></pre>
  
  <p>Here the transformer and the logger are 2 subscribers to the publishsubscribechannel. In this setup will the message flow to logger and transformer from the gateway happen asynchronously by default??...OR I need to do some other configuration to achieve the same.</p>