luster membership events.
You can read more about it in the 
<a href="http://doc.akka.io/docs/akka/2.4-SNAPSHOT/java/cluster-usage.html#Subscribe_to_Cluster_Events" target="_blank">documentation</a>.
How can cluster membership events be used?
</p>

<p> 
Let's take a look at an example that illustrates how workers, here named <b>backend</b>,
can detect and register to new master nodes, here named <b>frontend</b>.
</p>

<p>
The example application provides a service to transform text. When some text
is sent t