@GET

  @Path("/nodes")

  @Produces({ MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML })

  public NodesInfo getNodes(@QueryParam("states") String states) {

    init();

    ResourceScheduler sched = this.rm.getResourceScheduler();

    if (sched == null) {

      throw new NotFoundException("Null ResourceScheduler instance");

    }

    EnumSet<NodeState> acceptedStates;

    if (states == null) {

      acceptedStates = EnumSet.allOf(NodeState.class);

    } else {

      acceptedStates = EnumSet.noneOf(NodeState.class);

      for (String stateStr : states.split(",")) {

        acceptedStates.add(

            NodeState.valueOf(StringUtils.toUpperCase(stateStr)));

      }

    }

    Collection<RMNode> rmNodes = RMServerUtils.queryRMNodes(this.rm.getRMContext(),

        acceptedStates);

    NodesInfo nodesInfo = new NodesInfo();

    for (RMNode rmNode : rmNodes) {

      NodeInfo nodeInfo = new NodeInfo(rmNode, sched);

      if (EnumSet.of(NodeState.LOST, NodeState.DECOMMISSIONED, NodeState.REBOOTED)

          .contains(rmNode.getState())) {

        nodeInfo.setNodeHTTPAddress(EMPTY);

      }

      nodesInfo.add(nodeInfo);

    }

    return nodesInfo;

  }

public NodeInfo(RMNode ni, ResourceScheduler sched) {

    NodeId id = ni.getNodeID();

    SchedulerNodeReport report = sched.getNodeReport(id);

    this.numContainers = 0;

    this.usedMemoryMB = 0;

    this.availMemoryMB = 0;

    if (report != null) {

      this.numContainers = report.getNumContainers();

      this.usedMemoryMB = report.getUsedResource().getMemory();

      this.availMemoryMB = report.getAvailableResource().getMemory();

      this.usedVirtualCores = report.getUsedResource().getVirtualCores();

      this.availableVirtualCores = report.getAvailableResource().getVirtualCores();

    }

    this.id = id.toString();

    this.rack = ni.getRackName();

    this.nodeHostName = ni.getHostName();

    this.state = ni.getState();

    this.nodeHTTPAddress = ni.getHttpAddress();

    this.lastHealthUpdate = ni.getLastHealthReportTime();

    this.healthReport = String.valueOf(ni.getHealthReport());

 public static List<RMNode> queryRMNodes(RMContext context,

      EnumSet<NodeState> acceptedStates) {

    // nodes contains nodes that are NEW, RUNNING OR UNHEALTHY

    ArrayList<RMNode> results = new ArrayList<RMNode>();

    if (acceptedStates.contains(NodeState.NEW) ||

        acceptedStates.contains(NodeState.RUNNING) ||

        acceptedStates.contains(NodeState.UNHEALTHY)) {

      for (RMNode rmNode : context.getRMNodes().values()) {

        if (acceptedStates.contains(rmNode.getState())) {

          results.add(rmNode);

        }

      }

    }