private static HRegionServer setDrainingServer(final HRegionServer hrs) throws KeeperException {
   LOG.info(
       "Making "
           + hrs.getServerName()
           + " the draining server; "
           + "it has "
           + hrs.getNumberOfOnlineRegions()
           + " online regions");
   ZooKeeperWatcher zkw = hrs.getZooKeeper();
   String hrsDrainingZnode = ZKUtil.joinZNode(zkw.drainingZNode, hrs.getServerName().toString());
   ZKUtil.createWithParents(zkw, hrsDrainingZnode);
   return hrs;
 }
 private static HRegionServer unsetDrainingServer(final HRegionServer hrs) throws KeeperException {
   ZooKeeperWatcher zkw = hrs.getZooKeeper();
   String hrsDrainingZnode = ZKUtil.joinZNode(zkw.drainingZNode, hrs.getServerName().toString());
   ZKUtil.deleteNode(zkw, hrsDrainingZnode);
   return hrs;
 }