TestLeaderGroup.java

/**
 * Licensed to Ravel, Inc. under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  Ravel, Inc. 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.
 * 
 */
package org.goldenorb.zookeeper;

import static org.junit.Assert.*;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.concurrent.CountDownLatch;

import org.apache.zookeeper.ZooKeeper;
import org.goldenorb.zookeeper.OrbZKFailure;
import org.goldenorb.zookeeper.ZookeeperUtils;
import org.junit.Test;

public class TestLeaderGroup {
  
  private final static int NUM_OF_MEMBERS = 10;
  List<Thread> threads = new ArrayList<Thread>();
  List<TTracker> trackers = new ArrayList<TTracker>();
  
  
/**
 * 
 */
  @Test
  public void leaderGroupTest() throws IOException, InterruptedException, OrbZKFailure {

    ZooKeeper zk = ZookeeperUtils.connect("localhost:21810");
    String basePath = "/" + "Job";
    CountDownLatch startCountDownLatch = new CountDownLatch(NUM_OF_MEMBERS);
    CountDownLatch leaderChangeCdl = new CountDownLatch(NUM_OF_MEMBERS -1);
    CountDownLatch leaveCdl = new CountDownLatch(NUM_OF_MEMBERS);
    CountDownLatch dataChangeCdl = new CountDownLatch(NUM_OF_MEMBERS -1);
    for (int i = 0; i < NUM_OF_MEMBERS; i++) {
      TTracker tracker = new TTracker(zk, i,  basePath, startCountDownLatch, leaderChangeCdl, leaveCdl, dataChangeCdl);
      trackers.add(tracker);
      threads.add(new Thread(tracker));
      threads.get(i).start();
    }
    startCountDownLatch.await();
    int numOfLeaders = 0;
    int leader = -1;
    for(int i=0; i < NUM_OF_MEMBERS; i++){
      if(trackers.get(i).isLeader()){
        leader = i;
        numOfLeaders++;
      }
    }
    assertTrue(numOfLeaders == 1);
    trackers.get(leader).leave();
    leaderChangeCdl.await();
    numOfLeaders = 0;
    int newLeader = -1;
    for(int i=0; i < NUM_OF_MEMBERS; i++){
      if(i != leader){
        if(trackers.get(i).isLeader()){
          numOfLeaders++;
          newLeader = i;
        }
      }
    }
    assertTrue(numOfLeaders == 1);
    
    
    int newData = 9999;
    trackers.get(newLeader).changeMemberData(newData);
    dataChangeCdl.await();
    boolean allUpdated = true;
    for(int i=0; i < NUM_OF_MEMBERS; i++) {
      if (i != leader) {
        Collection<TMember> members = trackers.get(i).getMembers();
        boolean receivedUpdate = false;
        for(TMember member : members) {
          receivedUpdate = receivedUpdate || (member.getData() == newData);
          //System.err.println(i + ": " + Boolean.toString(receivedUpdate || (member.getData() == newData)));
        }
        allUpdated = allUpdated && receivedUpdate;
      }
    }
    assertTrue(allUpdated);
    
    
    for(int i=0; i < NUM_OF_MEMBERS; i++){
      if(i != leader){
        trackers.get(i).leave();
      }
    }
    leaveCdl.await();
    ZookeeperUtils.deleteNodeIfEmpty(zk, basePath);
  }
}