title: May I use 2 aggregators in one Spring Integration flow?
body: <p>I need to send message to 3 services, and aggregate result at the end.<br>
  This is easy via <code>publish-subscribe-channel-&gt;service-activator(s)-&gt;aggregator</code>.</p>
  
  <p>The problem appears when one of the services is in reality 2 calls to other services. At this point I want to introduce additional <code>publish-subscribe-channel</code> and aggregator.</p>
  
  <p>E.g.</p>
  
  <pre><code>publish-subscribe-channel1 -&gt; service-activator group1 -&gt; aggregator1
    \/-&gt; service call -&gt; publish-subscribe-channel2 -&gt; service-activator group2 -&gt; aggregator2 
  </code></pre>
  
  <p>As a result <code>aggregator2</code> doesn't group message(send them out one by one).</p>
  
  <p><code>Aggregator1</code> gets results from <code>aggregator2</code> and send out message without waiting for messages from service-activator group 1.</p>
  
  <p>Any suggestions?</p>