That's better. Cleaning up is clean.

sylvilagus/scala/src/main/scala/com/meatballhat/sylvilagus/ch02/HelloWorldProducer.scala

@@ -17,5 +17,7 @@ object HelloWorldProducer extends App {
         println("Publishing ", messageBody)
         channel.basicPublish("hello-exchange", "hola", null,
             messageBody.toCharArray().map(_.toByte))
+
+        connection.close()
     }
 }