/** Process the {@link WatchedEvent} for a node which represents an {@link AuthenticationKey} */
  void processChildNode(WatchedEvent event) throws KeeperException, InterruptedException {
    final String path = event.getPath();
    switch (event.getType()) {
      case NodeDeleted:
        // Key expired
        if (null == path) {
          log.error("Got null path for NodeDeleted event");
          return;
        }

        // Pull off the base ZK path and the '/' separator
        String childName = path.substring(baseNode.length() + 1);
        secretManager.removeKey(Integer.parseInt(childName));
        break;
      case None:
        // Not connected, don't care. We'll update when we're reconnected
        break;
      case NodeCreated:
        // New key created
        if (null == path) {
          log.error("Got null path for NodeCreated event");
          return;
        }
        // Get the data and reset the watcher
        AuthenticationKey key = deserializeKey(zk.getData(path, this, null));
        log.debug("Adding AuthenticationKey with keyId {}", key.getKeyId());
        secretManager.addKey(key);
        break;
      case NodeDataChanged:
        // Key changed, could happen on restart after not running Accumulo.
        if (null == path) {
          log.error("Got null path for NodeDataChanged event");
          return;
        }
        // Get the data and reset the watcher
        AuthenticationKey newKey = deserializeKey(zk.getData(path, this, null));
        // Will overwrite the old key if one exists
        secretManager.addKey(newKey);
        break;
      case NodeChildrenChanged:
        // no children for the children..
        log.warn("Unexpected NodeChildrenChanged event for authentication key node {}", path);
        break;
      default:
        log.warn("Unsupported event type: {}", event.getType());
        break;
    }
  }
 private int updateAuthKeys(String path) throws KeeperException, InterruptedException {
   int keysAdded = 0;
   for (String child : zk.getChildren(path, this)) {
     String childPath = path + "/" + child;
     try {
       // Get the node data and reset the watcher
       AuthenticationKey key = deserializeKey(zk.getData(childPath, this, null));
       secretManager.addKey(key);
       keysAdded++;
     } catch (NoNodeException e) {
       // The master expired(deleted) the key between when we saw it in getChildren() and when we
       // went to add it to our secret manager.
       log.trace("{} was deleted when we tried to access it", childPath);
     }
   }
   return keysAdded;
 }
 /**
  * Entry point to seed the local {@link AuthenticationKey} cache from ZooKeeper and set the first
  * watcher for future updates in ZooKeeper.
  */
 public void updateAuthKeys() throws KeeperException, InterruptedException {
   // Might cause two watchers on baseNode, but only at startup for each tserver.
   if (zk.exists(baseNode, this)) {
     log.info(
         "Added {} existing AuthenticationKeys to local cache from ZooKeeper",
         updateAuthKeys(baseNode));
   }
 }