Push the aggregate message size to Datadog

It is nice to track how much data is being produced.

Author: dasch

lib/kafka/datadog.rb

@@ -229,8 +229,12 @@ def produce_message(event)
         # This gets us the write rate.
         increment("producer.produce.messages", tags: tags.merge(topic: topic))
 
+        # Information about typical/average/95p message size.
         histogram("producer.produce.message_size", message_size, tags: tags.merge(topic: topic))
 
+        # Aggregate message size.
+        count("producer.produce.message_size.sum", message_size, tags: tags.merge(topic: topic))
+
         # This gets us the avg/max buffer size per producer.
         histogram("producer.buffer.size", buffer_size, tags: tags)