@Override protected void startUp() throws Exception { Futures.getUnchecked(ZKClientExt.ensureExists(zkClient, queueType.getPath())); refreshQueues(Futures.getUnchecked(zkClient.getChildren(queueType.getPath()))); ZKOperations.watchChildren(zkClient, queueType.getPath(), new ZKOperations.ChildrenCallback() { @Override public void updated(NodeChildren nodeChildren) { refreshQueues(nodeChildren); } }); }