title: HBase AggregationClient in HDInsight
body: <p>I am trying out the C# REST client accessing HBase in HDInsight.
  I would like to get a filtered row count without bringing results down to the client, and from what I've seen online, the AggregationClient coprocessor seems to be what I need. But I haven't been able to find any documentation as to whether it's available in HBase in HDInsight, and more specifically, available to the REST client.
  Anyone have any experience with it, or suggestions?</p>
  
  <p>Thanks.</p>