ambari/ambari-web/app/controllers/main/admin/highAvailability/nameNode/step4_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');

require('controllers/main/admin/misc_controller');

App.HighAvailabilityWizardStep4Controller = Em.Controller.extend({

  name:"highAvailabilityWizardStep4Controller",

  POLL_INTERVAL: 1000,

  isNextEnabled: false,

  pullCheckPointStatus: function () {
    var hostName = this.get('content.masterComponentHosts').findProperty('isCurNameNode', true).hostName;
    App.ajax.send({
      name: 'admin.high_availability.getNnCheckPointStatus',
      sender: this,
      data: {
        hostName: hostName
      },
      success: 'checkNnCheckPointStatus'
    });
  },

  checkNnCheckPointStatus: function (data) {
    var self = this;
    var journalTransactionInfo =  $.parseJSON(data.metrics.dfs.namenode.JournalTransactionInfo);
    var isInSafeMode = (data.metrics.dfs.namenode.Safemode != "");
    journalTransactionInfo = parseInt(journalTransactionInfo.LastAppliedOrWrittenTxId) - parseInt(journalTransactionInfo.MostRecentCheckpointTxId);
    if(journalTransactionInfo <= 1 && isInSafeMode){
      this.set("isNextEnabled", true);
      return;
    }

    window.setTimeout(function () {
      self.pullCheckPointStatus()
    }, self.POLL_INTERVAL);
  },

  done: function () {
    if (this.get('isNextEnabled')) {
      App.router.send('next');
    }
  }

});