Stopping participants and controllers

[Bruno Freudensprung]

Hi, I am a new user of Apache Helix, I started prototyping and so far I'm excited about it :). I have a question related to stopping participants and controllers. The demo code is the following : HelixManager manager = HelixManagerFactory.getZKHelixManager(CLUSTER_NAME, "localhost_7000", InstanceType.PARTICIPANT, ZK_ADDRESS); try {   StateMachineEngine stateMach = manager.getStateMachineEngine();   MasterSlaveStateModelFactory stateModelFactory = new MasterSlaveStateModelFactory();    stateMach.registerStateModelFactory(STATE_MODEL_NAME, stateModelFactory);    manager.connect();    System.in.read(); // wait for user input before stopping the participant } catch (Exception e) {    e.printStackTrace(); } finally {   manager.disconnect(); } My problem is the program is hanging after manager.disconnect() because some threads are still alive. They are created here: 1 - First one is created in the constructor of ZKHelixManager that is calling HelixPropertyFactory.getInstance().getHelixManagerProperty(zkAddress, clusterName)), that is creating a ConfigAccessor object that is creating a ZkClient (I don't know how to close it). 2 - Second one is the static SubscribeChangeEventProcessor thread of the org.apache.helix.manager.zk.CallbackHandler class. Could you tell me if I forgot something in my program? I guess I can try to call setDaemon(true) on SubscribeChangeEventProcessor, but I don't know how I can close the ZkClient. Thank you! Bruno.