ambari/ambari-web/app/controllers/main/host/bulk_operations_controller.js

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements. See the NOTICE file distributed with this
 * work for additional information regarding copyright ownership. The ASF
 * licenses this file to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

var App = require('app');
var batchUtils = require('utils/batch_scheduled_requests');
var hostsManagement = require('utils/hosts');
var O = Em.Object;

/**
 * @class BulkOperationsController
 */
App.BulkOperationsController = Em.Controller.extend({

  name: 'bulkOperationsController',

  /**
   * Bulk operation wrapper
   * @param {Object} operationData - data about bulk operation (action, hosts or hostComponents etc)
   * @param {Array} hosts - list of affected hosts
   * @method bulkOperation
   */
  bulkOperation: function (operationData, hosts) {
    if (operationData.componentNameFormatted) {
      if (operationData.action === 'RESTART') {
        this.bulkOperationForHostComponentsRestart(operationData, hosts);
      }
      else {
        if (operationData.action.indexOf('DECOMMISSION') == -1) {
          this.bulkOperationForHostComponents(operationData, hosts);
        }
        else {
          this.bulkOperationForHostComponentsDecommission(operationData, hosts);
        }
      }
    }
    else {
      if (operationData.action === 'SET_RACK_INFO') {
        this.bulkOperationForHostsSetRackInfo(operationData, hosts);
      }
      else {
        if (operationData.action === 'RESTART') {
          this.bulkOperationForHostsRestart(operationData, hosts);
        }
        else {
          if (operationData.action === 'PASSIVE_STATE') {
            this.bulkOperationForHostsPassiveState(operationData, hosts);
          }
          else {
            this.bulkOperationForHosts(operationData, hosts);
          }
        }
      }
    }
  },

  /**
   * Bulk operation (start/stop all) for selected hosts
   * @param {Object} operationData - data about bulk operation (action, hostComponents etc)
   * @param {Array} hosts - list of affected hosts
   * @return {$.ajax}
   */
  bulkOperationForHosts: function (operationData, hosts) {
    var self = this;
    return batchUtils.getComponentsFromServer({
      hosts: hosts.mapProperty('hostName'),
      passiveState: 'OFF',
      displayParams: ['host_components/HostRoles/component_name']
    }, function (data) {
      return self._getComponentsFromServerForHostsCallback(operationData, data);
    });
  },

  /**
   * run Bulk operation (start/stop all) for selected hosts
   * after host and components are loaded
   * @param operationData
   * @param data
   */
  _getComponentsFromServerForHostsCallback: function (operationData, data) {
    var query = [];
    var hostNames = [];
    var hostsMap = {};
    var clients = App.components.get('clients');

    data.items.forEach(function (host) {
      host.host_components.forEach(function (hostComponent) {
        if (!clients.contains((hostComponent.HostRoles.component_name))) {
          if (hostsMap[host.Hosts.host_name]) {
            hostsMap[host.Hosts.host_name].push(hostComponent.HostRoles.component_name);
          } else {
            hostsMap[host.Hosts.host_name] = [hostComponent.HostRoles.component_name];
          }
        }
      });
    });

    var nn_hosts = [];
    for (var hostName in hostsMap) {
      if (hostsMap.hasOwnProperty(hostName)) {
        var subQuery = '(HostRoles/component_name.in(%@)&HostRoles/host_name=' + hostName + ')';
        var components = hostsMap[hostName];

        if (components.length) {
          if (components.contains('NAMENODE')) {
            nn_hosts.push(hostName);
          }
          query.push(subQuery.fmt(components.join(',')));
        }
        hostNames.push(hostName);
      }
    }
    hostNames = hostNames.join(",");
    if (query.length) {
      query = query.join('|');
      var self = this;
      // if NameNode included, check HDFS NameNode checkpoint before stop NN
      var isHDFSStarted = 'STARTED' === App.Service.find('HDFS').get('workStatus');

      var request = function () {
        return App.ajax.send({
          name: 'common.host_components.update',
          sender: self,
          data: {
            query: query,
            HostRoles: {
              state: operationData.action
            },
            context: operationData.message,
            hostName: hostNames,
            noOpsMessage: Em.I18n.t('hosts.host.maintainance.allComponents.context')
          },
          success: 'bulkOperationForHostComponentsSuccessCallback'
        });
      };

      if (operationData.action === 'INSTALLED' && isHDFSStarted) {
        if (nn_hosts.length == 1) {
          return App.router.get('mainHostDetailsController').checkNnLastCheckpointTime(request, nn_hosts[0]);
        }
        if (nn_hosts.length == 2) {
          // HA enabled
          return App.router.get('mainServiceItemController').checkNnLastCheckpointTime(request);
        }
      }
      return request();
    }
    else {
      return App.ModalPopup.show({
        header: Em.I18n.t('rolling.nothingToDo.header'),
        body: Em.I18n.t('rolling.nothingToDo.body').format(Em.I18n.t('hosts.host.maintainance.allComponents.context')),
        secondary: false
      });
    }
  },

  bulkOperationForHostsSetRackInfo: function (operationData, hosts) {
    return hostsManagement.setRackInfo(operationData, hosts);
  },

  /**
   * Bulk restart for selected hosts
   * @param {Object} operationData - data about bulk operation (action, hostComponents etc)
   * @param {Ember.Enumerable} hosts - list of affected hosts
   */
  bulkOperationForHostsRestart: function (operationData, hosts) {
    return batchUtils.getComponentsFromServer({
      passiveState: 'OFF',
      hosts: hosts.mapProperty('hostName'),
      displayParams: ['host_components/HostRoles/component_name']
    }, this._getComponentsFromServerForRestartCallback);
  },

  /**
   *
   * @param {object} data
   * @private
   * @method _getComponentsFromServerCallback
   */
  _getComponentsFromServerForRestartCallback: function (data) {
    var hostComponents = [];
    data.items.forEach(function (host) {
      host.host_components.forEach(function (hostComponent) {
        hostComponents.push(O.create({
          componentName: hostComponent.HostRoles.component_name,
          hostName: host.Hosts.host_name
        }));
      })
    });
    // if NameNode included, check HDFS NameNode checkpoint before restart NN
    var isHDFSStarted = 'STARTED' === App.Service.find('HDFS').get('workStatus');
    var namenodes = hostComponents.filterProperty('componentName', 'NAMENODE');
    var nn_count = namenodes.get('length');

    if (nn_count == 1 && isHDFSStarted) {
      var hostName = namenodes.get('firstObject.hostName');
      App.router.get('mainHostDetailsController').checkNnLastCheckpointTime(function () {
        batchUtils.restartHostComponents(hostComponents, Em.I18n.t('rollingrestart.context.allOnSelectedHosts'), "HOST");
      }, hostName);
    }
    else {
      if (nn_count == 2 && isHDFSStarted) {
        // HA enabled
        App.router.get('mainServiceItemController').checkNnLastCheckpointTime(function () {
          batchUtils.restartHostComponents(hostComponents, Em.I18n.t('rollingrestart.context.allOnSelectedHosts'), "HOST");
        });
      }
      else {
        batchUtils.restartHostComponents(hostComponents, Em.I18n.t('rollingrestart.context.allOnSelectedHosts'), "HOST");
      }
    }
  },

  /**
   * Bulk turn on/off passive state for selected hosts
   * @param {Object} operationData - data about bulk operation (action, hostComponents etc)
   * @param {Array} hosts - list of affected hosts
   */
  bulkOperationForHostsPassiveState: function (operationData, hosts) {
    var self = this;

    return batchUtils.getComponentsFromServer({
      hosts: hosts.mapProperty('hostName'),
      displayParams: ['Hosts/maintenance_state']
    }, function (data) {
      return self._getComponentsFromServerForPassiveStateCallback(operationData, data)
    });
  },

  /**
   *
   * @param {object} operationData
   * @param {object} data
   * @returns {$.ajax|App.ModalPopup}
   * @private
   * @method _getComponentsFromServerForPassiveStateCallback
   */
  _getComponentsFromServerForPassiveStateCallback: function (operationData, data) {
    var hostNames = [];

    data.items.forEach(function (host) {
      if (host.Hosts.maintenance_state !== operationData.state) {
        hostNames.push(host.Hosts.host_name);
      }
    });
    if (hostNames.length) {
      return App.ajax.send({
        name: 'bulk_request.hosts.passive_state',
        sender: this,
        data: {
          hostNames: hostNames.join(','),
          passive_state: operationData.state,
          requestInfo: operationData.message
        },
        success: 'updateHostPassiveState'
      });
    }
    return App.ModalPopup.show({
      header: Em.I18n.t('rolling.nothingToDo.header'),
      body: Em.I18n.t('hosts.bulkOperation.passiveState.nothingToDo.body'),
      secondary: false
    });
  },

  updateHostPassiveState: function (data, opt, params) {
    return batchUtils.infoPassiveState(params.passive_state);
  },
  /**
   * Bulk operation for selected hostComponents
   * @param {Object} operationData - data about bulk operation (action, hostComponents etc)
   * @param {Array} hosts - list of affected hosts
   */
  bulkOperationForHostComponents: function (operationData, hosts) {
    var self = this;

    return batchUtils.getComponentsFromServer({
      components: [operationData.componentName],
      hosts: hosts.mapProperty('hostName'),
      passiveState: 'OFF'
    }, function (data) {
      return self._getComponentsFromServerForHostComponentsCallback(operationData, data)
    });
  },

  /**
   *
   * @param {object} operationData
   * @param {object} data
   * @returns {$.ajax|App.ModalPopup}
   * @private
   */
  _getComponentsFromServerForHostComponentsCallback: function (operationData, data) {
    if (data.items) {
      var hostsWithComponentInProperState = data.items.mapProperty('Hosts.host_name');
      return App.ajax.send({
        name: 'common.host_components.update',
        sender: this,
        data: {
          HostRoles: {
            state: operationData.action
          },
          query: 'HostRoles/component_name=' + operationData.componentName + '&HostRoles/host_name.in(' + hostsWithComponentInProperState.join(',') + ')&HostRoles/maintenance_state=OFF',
          context: operationData.message + ' ' + operationData.componentNameFormatted,
          level: 'SERVICE',
          noOpsMessage: operationData.componentNameFormatted
        },
        success: 'bulkOperationForHostComponentsSuccessCallback'
      });
    }
    return App.ModalPopup.show({
      header: Em.I18n.t('rolling.nothingToDo.header'),
      body: Em.I18n.t('rolling.nothingToDo.body').format(operationData.componentNameFormatted),
      secondary: false
    });
  },

  /**
   * Bulk decommission/recommission for selected hostComponents
   * @param {Object} operationData
   * @param {Array} hosts
   */
  bulkOperationForHostComponentsDecommission: function (operationData, hosts) {
    var self = this;

    return batchUtils.getComponentsFromServer({
      components: [operationData.realComponentName],
      hosts: hosts.mapProperty('hostName'),
      passiveState: 'OFF',
      displayParams: ['host_components/HostRoles/state']
    }, function (data) {
      return self._getComponentsFromServerForHostComponentsDecommissionCallBack(operationData, data)
    });
  },

  /**
   * run Bulk decommission/recommission for selected hostComponents
   * after host and components are loaded
   * @param operationData
   * @param data
   * @method _getComponentsFromServerForHostComponentsDecommissionCallBack
   */
  _getComponentsFromServerForHostComponentsDecommissionCallBack: function (operationData, data) {
    var service = App.Service.find(operationData.serviceName);
    var components = [];

    data.items.forEach(function (host) {
      host.host_components.forEach(function (hostComponent) {
        components.push(O.create({
          componentName: hostComponent.HostRoles.component_name,
          hostName: host.Hosts.host_name,
          workStatus: hostComponent.HostRoles.state
        }))
      });
    });

    if (components.length) {
      var hostsWithComponentInProperState = components.mapProperty('hostName');
      var turn_off = operationData.action.indexOf('OFF') !== -1;
      var svcName = operationData.serviceName;
      var masterName = operationData.componentName;
      var slaveName = operationData.realComponentName;
      var hostNames = hostsWithComponentInProperState.join(',');
      if (turn_off) {
        // For recommession
        if (svcName === "YARN" || svcName === "HBASE" || svcName === "HDFS") {
          App.router.get('mainHostDetailsController').doRecommissionAndStart(hostNames, svcName, masterName, slaveName);
        }
      } else {
        hostsWithComponentInProperState = components.filterProperty('workStatus', 'STARTED').mapProperty('hostName');
        //For decommession
        if (svcName == "HBASE") {
          // HBASE service, decommission RegionServer in batch requests
          this.warnBeforeDecommission(hostNames);
        } else {
          var parameters = {
            "slave_type": slaveName
          };
          var contextString = turn_off ? 'hosts.host.' + slaveName.toLowerCase() + '.recommission' :
          'hosts.host.' + slaveName.toLowerCase() + '.decommission';
          if (turn_off) {
            parameters['included_hosts'] = hostsWithComponentInProperState.join(',')
          }
          else {
            parameters['excluded_hosts'] = hostsWithComponentInProperState.join(',');
          }
          App.ajax.send({
            name: 'bulk_request.decommission',
            sender: this,
            data: {
              context: Em.I18n.t(contextString),
              serviceName: service.get('serviceName'),
              componentName: operationData.componentName,
              parameters: parameters,
              noOpsMessage: operationData.componentNameFormatted
            },
            success: 'bulkOperationForHostComponentsSuccessCallback'
          });
        }
      }
    }
    else {
      App.ModalPopup.show({
        header: Em.I18n.t('rolling.nothingToDo.header'),
        body: Em.I18n.t('rolling.nothingToDo.body').format(operationData.componentNameFormatted),
        secondary: false
      });
    }
  },


  /**
   * get info about regionserver passive_state
   * @method warnBeforeDecommission
   * @param {String} hostNames
   * @return {$.ajax}
   */
  warnBeforeDecommission: function (hostNames) {
    return App.ajax.send({
      'name': 'host_components.hbase_regionserver.active',
      'sender': this,
      'data': {
        hostNames: hostNames
      },
      success: 'warnBeforeDecommissionSuccess'
    });
  },

  /**
   * check is hbase regionserver in mm. If so - run decommission
   * otherwise shows warning
   * @method warnBeforeDecommission
   * @param {Object} data
   * @param {Object} opt
   * @param {Object} params
   */
  warnBeforeDecommissionSuccess: function(data, opt, params) {
    if (Em.get(data, 'items.length')) {
      return App.router.get('mainHostDetailsController').showHbaseActiveWarning();
    }
    return App.router.get('mainHostDetailsController').checkRegionServerState(params.hostNames);
  },

  /**
   * Bulk restart for selected hostComponents
   * @param {Object} operationData
   * @param {Array} hosts
   */
  bulkOperationForHostComponentsRestart: function (operationData, hosts) {
    var self = this;
    return batchUtils.getComponentsFromServer({
      components: [operationData.componentName],
      hosts: hosts.mapProperty('hostName'),
      passiveState: 'OFF',
      displayParams: ['Hosts/maintenance_state', 'host_components/HostRoles/stale_configs', 'host_components/HostRoles/maintenance_state']
    }, function (data) {
      return self._getComponentsFromServerForHostComponentsRestartCallback(operationData, data);
    });
  },

  _getComponentsFromServerForHostComponentsRestartCallback: function (operationData, data) {
    var wrappedHostComponents = [];
    var service = App.Service.find(operationData.serviceName);

    data.items.forEach(function (host) {
      host.host_components.forEach(function (hostComponent) {
        wrappedHostComponents.push(O.create({
          componentName: hostComponent.HostRoles.component_name,
          serviceName: operationData.serviceName,
          hostName: host.Hosts.host_name,
          hostPassiveState: host.Hosts.maintenance_state,
          staleConfigs: hostComponent.HostRoles.stale_configs,
          passiveState: hostComponent.HostRoles.maintenance_state
        }));
      });
    });

    if (wrappedHostComponents.length) {
      return batchUtils.showRollingRestartPopup(wrappedHostComponents.objectAt(0).get('componentName'), service.get('displayName'), service.get('passiveState') === "ON", false, wrappedHostComponents);
    }
    return App.ModalPopup.show({
      header: Em.I18n.t('rolling.nothingToDo.header'),
      body: Em.I18n.t('rolling.nothingToDo.body').format(operationData.componentNameFormatted),
      secondary: false
    });
  },

  updateHostComponentsPassiveState: function (data, opt, params) {
    return batchUtils.infoPassiveState(params.passive_state);
  },

  /**
   * Show BO popup after bulk request
   * @method bulkOperationForHostComponentsSuccessCallback
   */
  bulkOperationForHostComponentsSuccessCallback: function (data, opt, params, req) {
    if (!data && req.status == 200) {
      return App.ModalPopup.show({
        header: Em.I18n.t('rolling.nothingToDo.header'),
        body: Em.I18n.t('rolling.nothingToDo.body').format(params.noOpsMessage || Em.I18n.t('hosts.host.maintainance.allComponents.context')),
        secondary: false
      });
    }
    return App.router.get('userSettingsController').dataLoading('show_bg').done(function (initValue) {
      if (initValue) {
        App.router.get('backgroundOperationsController').showPopup();
      }
    });
  },

  /**
   * Returns all hostNames if amount is less than {minShown} or
   * first elements of array (number of elements - {minShown}) converted to string
   * @param {Array} hostNames - array of all listed hostNames
   * @param {String} divider - string to separate hostNames
   * @param {Number} minShown - min amount of hostName to be shown
   * @returns {String} hostNames
   * @method _showHostNames
   * @private
   */
  _showHostNames: function(hostNames, divider, minShown) {
    if (hostNames.length > minShown) {
      return hostNames.slice(0, minShown).join(divider) + divider + Em.I18n.t("installer.step8.other").format(hostNames.length - minShown);
    }
    return hostNames.join(divider);
  },

  /**
   * Confirmation Popup for bulk Operations
   */
  bulkOperationConfirm: function(operationData, selection) {
    var hostsNames = [],
      queryParams = [];
    // @todo remove using external controller
    switch(selection) {
      case 's':
        hostsNames = App.router.get('mainHostController.content').filterProperty('selected').mapProperty('hostName');
        if(hostsNames.length > 0){
          queryParams.push({
            key: 'Hosts/host_name',
            value: hostsNames,
            type: 'MULTIPLE'
          });
        }
        break;
      case 'f':
        queryParams = App.router.get('mainHostController').getQueryParameters(true).filter(function (obj) {
          return !(obj.key == 'page_size' || obj.key == 'from');
        });
        break;
    }

    if (operationData.action === 'SET_RACK_INFO') {
      this.getHostsForBulkOperations(queryParams, operationData, null);
      return;
    }

    var loadingPopup = App.ModalPopup.show({
      header: Em.I18n.t('jobs.loadingTasks'),
      primary: false,
      secondary: false,
      bodyClass: Em.View.extend({
        template: Em.Handlebars.compile('<div class="spinner"></div>')
      })
    });

    this.getHostsForBulkOperations(queryParams, operationData, loadingPopup);
  },

  getHostsForBulkOperations: function (queryParams, operationData, loadingPopup) {
    return App.ajax.send({
      name: 'hosts.bulk.operations',
      sender: this,
      data: {
        parameters: App.router.get('updateController').computeParameters(queryParams),
        operationData: operationData,
        loadingPopup: loadingPopup
      },
      success: 'getHostsForBulkOperationSuccessCallback'
    });
  },

  _convertHostsObjects: function (hosts) {
    return hosts.map(function (host) {
      return {
        index: host.index,
        id: host.id,
        clusterId: host.cluster_id,
        passiveState: host.passive_state,
        hostName: host.host_name,
        hostComponents: host.host_components
      }
    });
  },

  getHostsForBulkOperationSuccessCallback: function(json, opt, param) {
    var self = this;
    var operationData = param.operationData;
    var hosts = this._convertHostsObjects(App.hostsMapper.map(json, true));
    // no hosts - no actions
    if (!hosts.length) {
      return;
    }

    Em.tryInvoke(param.loadingPopup, 'hide');

    if ('SET_RACK_INFO' === operationData.action) {
      return self.bulkOperation(operationData, hosts);
    }

    var hostNames = hosts.mapProperty('hostName');
    var hostNamesSkipped = [];
    if ('DECOMMISSION' === operationData.action) {
      hostNamesSkipped = this._getSkippedForDecommissionHosts(json, hosts, operationData);
    }
    if ('PASSIVE_STATE' === operationData.action) {
      hostNamesSkipped = this._getSkippedForPassiveStateHosts(hosts);
    }

    var message = operationData.componentNameFormatted ?
      Em.I18n.t('hosts.bulkOperation.confirmation.hostComponents').format(operationData.message, operationData.componentNameFormatted, hostNames.length) :
      Em.I18n.t('hosts.bulkOperation.confirmation.hosts').format(operationData.message, hostNames.length);

    return App.ModalPopup.show({
      header: Em.I18n.t('hosts.bulkOperation.confirmation.header'),
      hostNames: hostNames.join("\n"),
      visibleHosts: self._showHostNames(hostNames, "\n", 3),
      hostNamesSkippedVisible: self._showHostNames(hostNamesSkipped, "\n", 3),
      expanded: false,

      hostNamesSkipped: function() {
        return hostNamesSkipped.length ? hostNamesSkipped.join("\n") : false;
      }.property(),

      didInsertElement: function() {
        this.set('expanded', hostNames.length <= 3);
      },
      onPrimary: function() {
        self.bulkOperation(operationData, hosts);
        this._super();
      },

      bodyClass: Em.View.extend({
        templateName: require('templates/main/host/bulk_operation_confirm_popup'),
        message: message,
        textareaVisible: false,

        warningInfo: function() {
          switch (operationData.action) {
            case "DECOMMISSION":
              return Em.I18n.t('hosts.bulkOperation.warningInfo.body');
            case "PASSIVE_STATE":
              return operationData.state === 'OFF' ? Em.I18n.t('hosts.passiveMode.popup.version.mismatch.multiple')
                .format(App.StackVersion.find().findProperty('isCurrent').get('repositoryVersion.repositoryVersion')) : "";
            default:
              return ""
          }
        }.property(),

        textTrigger: function() {
          this.toggleProperty('textareaVisible');
        },

        showAll: function() {
          this.set('parentView.visibleHosts', this.get('parentView.hostNames'));
          this.set('parentView.hostNamesSkippedVisible', this.get('parentView.hostNamesSkipped'));
          this.set('parentView.expanded', true);
        },

        putHostNamesToTextarea: function() {
          var hostNames = this.get('parentView.hostNames');
          if (this.get('textareaVisible')) {
            var wrapper = $(".task-detail-log-maintext");
            $('.task-detail-log-clipboard').html(hostNames).width(wrapper.width()).height(250);
            Em.run.next(function() {
              $('.task-detail-log-clipboard').select();
            });
          }
        }.observes('textareaVisible')

      })
    });
  },

  /**
   * @param {object} json
   * @param {object[]} hosts
   * @param {object} operationData
   * @returns {string[]}
   * @private
   * @method _getSkippedForDecommissionHosts
   */
  _getSkippedForDecommissionHosts: function (json, hosts, operationData) {
    var hostComponentStatusMap = {}; // "DATANODE_c6401.ambari.apache.org" => "STARTED"
    var hostComponentIdMap = {}; // "DATANODE_c6401.ambari.apache.org" => "DATANODE"
    if (json.items) {
      json.items.forEach(function(host) {
        if (host.host_components) {
          host.host_components.forEach(function(component) {
            hostComponentStatusMap[component.id] = component.HostRoles.state;
            hostComponentIdMap[component.id] = component.HostRoles.component_name;
          });
        }
      });
    }
    return hosts.filter(function(host) {
      return host.hostComponents.filter(function(component) {
        return hostComponentIdMap[component] == operationData.realComponentName && hostComponentStatusMap[component] == 'INSTALLED';
      }).length > 0;
    }).mapProperty('hostName');
  },

  /**
   * Exclude <code>outOfSyncHosts</code> hosts for PASSIVE request
   *
   * @param {object[]} hosts
   * @returns {string[]}
   * @private
   * @method _getSkippedForPassiveStateHosts
   */
  _getSkippedForPassiveStateHosts: function (hosts) {
    var hostNames = hosts.mapProperty('hostName');
    var hostNamesSkipped = [];
    var outOfSyncHosts = App.StackVersion.find().findProperty('isCurrent').get('outOfSyncHosts');
    for (var i = 0; i < outOfSyncHosts.length; i++) {
      if (hostNames.contains(outOfSyncHosts[i])) {
        hostNamesSkipped.push(outOfSyncHosts[i]);
      }
    }
    return hostNamesSkipped;
  }

});