クラスター環境にログインすると、zookeeper で以下のエラーを受け取りました。hbase に付属するデフォルトの Zookeeper を使用しています。
HBase is able to connect to ZooKeeper but the connection closes immediately.
This could be a sign that the server has too many connections (30 is the default)
Consider inspecting your ZK server logs for that error and then make sure you
are reusing HBase Configuration as often as you can. See HTable's javadoc for
more information.