add more info on rabbitmq river

Author: kimchy

guide/reference/river/rabbitmq.textile

@@ -15,7 +15,7 @@ p. RabbitMQ River allows to automatically index a rabbitmq queue. The format of
 { "tweet" : { "text" : "another tweet" } }    
 </pre>
 
-p. Creating the rabbitmq river is as simple as:
+p. Creating the rabbitmq river is as simple as (all configuration parameters are provided, with default values):
 
 <pre class="prettyprint">
 curl -XPUT 'localhost:9200/_river/my_river/_meta' -d '{
@@ -28,16 +28,21 @@ curl -XPUT 'localhost:9200/_river/my_river/_meta' -d '{
         "vhost" : "/",
         "queue" : "elasticsearch",
         "exchange" : "elasticsearch",
-        "routing_key" : "elasticsearch"
+        "routing_key" : "elasticsearch",
+        "exchange_type" : "direct",
+        "exchange_durable" : true,
+        "queue_durable" : true,
+        "queue_auto_delete" : false
     },
     "index" : {
         "bulk_size" : 100,
-        "bulk_timeout" : "10ms"
+        "bulk_timeout" : "10ms",
+        "ordered" : false
     }
 }'
 </pre>
 
-p. The river is automatically bulking queue messages if the queue is overloaded, allowing for faster catchup with the messages streamed into the queue.
+p. The river is automatically bulking queue messages if the queue is overloaded, allowing for faster catchup with the messages streamed into the queue. The `ordered` flag allows to make sure that the messages will be indexed in the same order as they arrive in the query by blocking on the bulk request before picking up the next data to be indexed. It can also be used as a simple way to throttle indexing.
 
 p. The rabbitmq river is provided as a plugin and can be installed using @plugin -install river-rabbitmq@.