/*
   * public synchronized ArrayList<Request> getWorkloadsList() {
   * ArrayList<Request> workloads = new ArrayList<Request>();
   *
   * LOG.debug("Reading " + parentZnode +
   * Constants.DEFAULT_ZOOKEEPER_ZNODE_WORKLOADS);
   *
   * try { List<String> children = getChildren(parentZnode +
   * Constants.DEFAULT_ZOOKEEPER_ZNODE_WORKLOADS, null);
   *
   * if (!children.isEmpty()) { for (String child : children) { Request
   * request = new Request(); String workloadZnode = parentZnode +
   * Constants.DEFAULT_ZOOKEEPER_ZNODE_WORKLOADS + "/" + child; Stat stat =
   * zkc.exists(workloadZnode, false); if (stat != null) { byte[] bytes =
   * zkc.getData(workloadZnode, false, stat); try {
   * deserializer.deserialize(request, bytes); workloads.add(request); } catch
   * (TException e) { e.printStackTrace(); } } } } } catch (Exception e) {
   * e.printStackTrace(); }
   *
   * return workloads; }
   */
  public synchronized ArrayList<String> getClientsList() {
    ArrayList<String> clients = new ArrayList<String>();

    LOG.debug("Reading " + parentZnode + Constants.DEFAULT_ZOOKEEPER_ZNODE_CLIENTS);

    try {
      List<String> children =
          getChildren(parentZnode + Constants.DEFAULT_ZOOKEEPER_ZNODE_CLIENTS, null);
      if (!children.isEmpty()) {
        for (String child : children) {
          clients.add(child);
        }
      }
    } catch (Exception e) {
      e.printStackTrace();
    }

    return clients;
  }
  private synchronized void getZkRunning() throws Exception {
    LOG.debug("Reading " + parentZnode + Constants.DEFAULT_ZOOKEEPER_ZNODE_SERVERS_RUNNING);
    List<String> children =
        getChildren(
            parentZnode + Constants.DEFAULT_ZOOKEEPER_ZNODE_SERVERS_RUNNING, new RunningWatcher());

    if (!children.isEmpty()) {
      for (String child : children) {
        // If stop-wms.sh is executed and WMS_MANAGES_ZK then zookeeper
        // is stopped abruptly.
        // Second scenario is when ZooKeeper fails for some reason
        // regardless of whether WMS
        // manages it. When either happens the WmsServer running znodes
        // still exist in ZooKeeper
        // and we see them at next startup. When they eventually timeout
        // we get node deleted events for a server that no longer
        // exists. So, only recognize
        // WmsServer running znodes that have timestamps after last
        // WmsMaster startup.
        Scanner scn = new Scanner(child);
        scn.useDelimiter(":");
        String hostName = scn.next();
        String instance = scn.next();
        int infoPort = Integer.parseInt(scn.next());
        long serverStartTimestamp = Long.parseLong(scn.next());
        scn.close();

        if (serverStartTimestamp < startupTimestamp) continue;

        if (!runningServers.contains(child)) {
          LOG.debug("Watching running [" + child + "]");
          zkc.exists(
              parentZnode + Constants.DEFAULT_ZOOKEEPER_ZNODE_SERVERS_RUNNING + "/" + child,
              new RunningWatcher());
          runningServers.add(child);
        }
      }
      metrics.setTotalRunning(runningServers.size());
    } else {
      metrics.setTotalRunning(0);
    }
  }
  private void getServersFile() throws Exception {
    InputStream is = this.getClass().getResourceAsStream("/servers");
    if (is == null) throw new IOException("Cannot find servers file");

    BufferedReader br = new BufferedReader(new InputStreamReader(is));
    configuredServers.clear();
    String line;
    while ((line = br.readLine()) != null) {
      configuredServers.add(line);
    }

    Collections.sort(configuredServers);

    if (configuredServers.size() < 1) throw new IOException("No entries found in servers file");

    int lnum = 1;
    for (int i = 0; i < configuredServers.size(); i++) {
      LOG.debug("servers file line " + lnum + " [" + configuredServers.get(i) + "]");
      lnum++;
    }
  }