HBASE-13086 Show ZK root node on Master WebUI

hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ZooKeeperWatcher.java

@@ -370,6 +370,13 @@ public class ZooKeeperWatcher implements Watcher, Abortable, Closeable {
     return quorum;
   }
 
+  /**
+   * @return the base znode of this zookeeper connection instance.
+   */
+  public String getBaseZNode() {
+    return baseZNode;
+  }
+
   /**
    * Method called from ZooKeeper for events and connection status.
    * <p>

hbase-server/src/main/jamon/org/apache/hadoop/hbase/tmpl/master/MasterStatusTmpl.jamon

@@ -254,6 +254,11 @@ AssignmentManager assignmentManager = master.getAssignmentManager();
                     <td> <% formatZKString() %> </td>
                     <td>Addresses of all registered ZK servers. For more, see <a href="/zk.jsp">zk dump</a>.</td>
                 </tr>
+                <tr>
+                    <td>Zookeeper Base Path</td>
+                    <td> <% master.getZooKeeper().getBaseZNode() %></td>
+                    <td>Root node of this cluster in ZK.</td>
+                </tr>
                 <tr>
                     <td>HBase Root Directory</td>
                     <td><% FSUtils.getRootDir(master.getConfiguration()).toString() %></td>