title: Issue in Elastic Search Sum Aggregation
body: <p>I am trying to the example from the elastic search site with my own parameters, but it is not working.</p>
  
  <p>Query:</p>
  
  <pre><code>{
    "query": {
      "filtered": {
        "query": {
          "match_all": {}
        },
        "filter": {
          "range": {
            "activity_date": {
              "from": "2013-11-01",
              "to": "2014-11-01"
            }
          }
        }
      }
    },
    "aggs": {
      "net_ordered_units": {
        "sum": {
          "field": "net_ordered_units"
        }
      }
    }
  }
  </code></pre>
  
  <p>Error I get:</p>
  
  <pre><code>{
    "error": "SearchPhaseExecutionException[Failed to execute phase [query_fetch], all shards failed; shardFailures {[YoGKlejVTC6jhg_OgPWXyTg][test][0]: SearchParseException[[test][0]: query[ConstantScore(cache(activity_date:[1383264000000 TO 1414886399999]))],from[-1],size[-1]: Parse Failure [Failed to parse source [{\"query\": {\"filtered\":{\"query\":{\"match_all\":{}},\"filter\":{\"range\":{\"activity_date\":{\"from\":\"2013-11-01\",\"to\":\"2014-11-01\"}}}}},\"aggs\":{\"net_ordered_units\":{\"sum\": {\"field\":\"net_ordered_units\"}}}}]]]; nested: SearchParseException[[test][0]: query[ConstantScore(cache(activity_date:[1383264000000 TO 1414886399999]))],from[-1],size[-1]: Parse Failure [No parser for element [aggs]]]; }]", 
    "status": 400
  }
  </code></pre>
  
  <p>What is shard failure here? And it says no parser for aggs, what should I do here?
  Basically, I need to perform operations like sum and then find the max out of it.
  How should I modify the above code to get that?</p>