Java Code Examples for org.apache.zookeeper.data.Stat#getVersion()

@Override
public List<HelixProperty.Stat> getPropertyStats(List<PropertyKey> keys) {
  if (keys == null || keys.size() == 0) {
    return Collections.emptyList();
  }

  List<HelixProperty.Stat> propertyStats = new ArrayList<>(keys.size());
  List<String> paths = new ArrayList<>(keys.size());
  for (PropertyKey key : keys) {
    paths.add(key.getPath());
  }
  Stat[] zkStats = _baseDataAccessor.getStats(paths, 0);

  for (int i = 0; i < keys.size(); i++) {
    Stat zkStat = zkStats[i];
    HelixProperty.Stat propertyStat = null;
    if (zkStat != null) {
      propertyStat =
          new HelixProperty.Stat(zkStat.getVersion(), zkStat.getCtime(), zkStat.getMtime(), zkStat.getEphemeralOwner());
    }
    propertyStats.add(propertyStat);
  }

  return propertyStats;
}
 

@Override
public List<HelixProperty.Stat> getPropertyStats(List<PropertyKey> keys) {
  if (keys == null || keys.size() == 0) {
    return Collections.emptyList();
  }

  List<HelixProperty.Stat> propertyStats = new ArrayList<>(keys.size());
  List<String> paths = new ArrayList<>(keys.size());
  for (PropertyKey key : keys) {
    paths.add(key.getPath());
  }
  Stat[] zkStats = _baseDataAccessor.getStats(paths, 0);

  for (int i = 0; i < keys.size(); i++) {
    Stat zkStat = zkStats[i];
    HelixProperty.Stat propertyStat = null;
    if (zkStat != null) {
      propertyStat =
          new HelixProperty.Stat(zkStat.getVersion(), zkStat.getCtime(), zkStat.getMtime(),
              zkStat.getEphemeralOwner());
    }
    propertyStats.add(propertyStat);
  }

  return propertyStats;
}
 

@Override
public HelixProperty.Stat getPropertyStat(PropertyKey key) {
  PropertyType type = key.getType();
  String path = key.getPath();
  int options = constructOptions(type);
  try {
    Stat stat = _baseDataAccessor.getStat(path, options);
    if (stat != null) {
      return new HelixProperty.Stat(stat.getVersion(), stat.getCtime(), stat.getMtime(), stat.getEphemeralOwner());
    }
  } catch (ZkNoNodeException e) {

  }

  return null;
}
 

private void applyNewData(String fullPath, int resultCode, Stat stat, byte[] bytes)
{
    if ( resultCode == KeeperException.Code.OK.intValue() ) // otherwise - node must have dropped or something - we should be getting another event
    {
        ChildData data = new ChildData(fullPath, stat, bytes);
        ChildData previousData = currentData.put(fullPath, data);
        if ( previousData == null ) // i.e. new
        {
            offerOperation(new EventOperation(this, new PathChildrenCacheEvent(PathChildrenCacheEvent.Type.CHILD_ADDED, data)));
        }
        else if ( previousData.getStat().getVersion() != stat.getVersion() )
        {
            offerOperation(new EventOperation(this, new PathChildrenCacheEvent(PathChildrenCacheEvent.Type.CHILD_UPDATED, data)));
        }
        updateInitialSet(ZKPaths.getNodeFromPath(fullPath), data);
    }
}
 

@Override
public HelixProperty.Stat getPropertyStat(PropertyKey key) {
  PropertyType type = key.getType();
  String path = key.getPath();
  try {
    Stat stat = _baseDataAccessor.getStat(path, 0);
    if (stat != null) {
      return new HelixProperty.Stat(stat.getVersion(), stat.getCtime(), stat.getMtime(),
          stat.getEphemeralOwner());
    }
  } catch (ZkNoNodeException e) {

  }

  return null;
}
 

/**
 * publish the version number of the next JobModel
 * @param oldVersion - used to validate, that no one has changed the version in the meanwhile.
 * @param newVersion - new version.
 */
public void publishJobModelVersion(String oldVersion, String newVersion) {
  Stat stat = new Stat();
  String currentVersion = zkClient.readData(keyBuilder.getJobModelVersionPath(), stat);
  metrics.reads.inc();
  LOG.info("publishing new version: " + newVersion + "; oldVersion = " + oldVersion + "(" + stat
      .getVersion() + ")");

  if (currentVersion != null && !currentVersion.equals(oldVersion)) {
    throw new SamzaException(
        "Someone changed JobModelVersion while the leader was generating one: expected" + oldVersion + ", got " + currentVersion);
  }
  // data version is the ZK version of the data from the ZK.
  int dataVersion = stat.getVersion();
  try {
    stat = zkClient.writeDataReturnStat(keyBuilder.getJobModelVersionPath(), newVersion, dataVersion);
    metrics.writes.inc();
  } catch (Exception e) {
    String msg = "publish job model version failed for new version = " + newVersion + "; old version = " + oldVersion;
    LOG.error(msg, e);
    throw new SamzaException(msg, e);
  }
  LOG.info("published new version: " + newVersion + "; expected data version = " + (dataVersion + 1) +
      "(actual data version after update = " + stat.getVersion() + ")");
}
 

/**
 * Returns the version of the node if it exists or <code>-1</code> if it doesn't.
 *
 * @param pathInZooKeeper Path in ZooKeeper to check
 * @return Version of the ZNode if the path exists, <code>-1</code> otherwise.
 * @throws Exception If the ZooKeeper operation fails
 */
public int exists(String pathInZooKeeper) throws Exception {
	checkNotNull(pathInZooKeeper, "Path in ZooKeeper");

	final String path = normalizePath(pathInZooKeeper);

	Stat stat = client.checkExists().forPath(path);

	if (stat != null) {
		return stat.getVersion();
	}

	return -1;
}
 

/**
 * Try to own the task by transitioning the zk node data from UNASSIGNED to OWNED.
 * <p>
 * This method is also used to periodically heartbeat the task progress by transitioning the node
 * from OWNED to OWNED.
 * <p>
 * @param isFirstTime shows whther it's the first attempt.
 * @param zkw zk wathcer
 * @param server name
 * @param task to own
 * @param taskZKVersion version of the task in zk
 * @return non-negative integer value when task can be owned by current region server otherwise -1
 */
protected static int attemptToOwnTask(boolean isFirstTime, ZKWatcher zkw,
    ServerName server, String task, int taskZKVersion) {
  int latestZKVersion = FAILED_TO_OWN_TASK;
  try {
    SplitLogTask slt = new SplitLogTask.Owned(server);
    Stat stat = zkw.getRecoverableZooKeeper().setData(task, slt.toByteArray(), taskZKVersion);
    if (stat == null) {
      LOG.warn("zk.setData() returned null for path " + task);
      SplitLogCounters.tot_wkr_task_heartbeat_failed.increment();
      return FAILED_TO_OWN_TASK;
    }
    latestZKVersion = stat.getVersion();
    SplitLogCounters.tot_wkr_task_heartbeat.increment();
    return latestZKVersion;
  } catch (KeeperException e) {
    if (!isFirstTime) {
      if (e.code().equals(KeeperException.Code.NONODE)) {
        LOG.warn("NONODE failed to assert ownership for " + task, e);
      } else if (e.code().equals(KeeperException.Code.BADVERSION)) {
        LOG.warn("BADVERSION failed to assert ownership for " + task, e);
      } else {
        LOG.warn("failed to assert ownership for " + task, e);
      }
    }
  } catch (InterruptedException e1) {
    LOG.warn("Interrupted while trying to assert ownership of " + task + " "
        + StringUtils.stringifyException(e1));
    Thread.currentThread().interrupt();
  }
  SplitLogCounters.tot_wkr_task_heartbeat_failed.increment();
  return FAILED_TO_OWN_TASK;
}
 

/**
 * Pulls data from ZooKeeper.  If isInit is false, it will only parse the
 * next secret and version.  If isInit is true, it will also parse the current
 * and previous secrets, and the next rollover date; it will also init the
 * secrets.  Hence, isInit should only be true on startup.
 * @param isInit  see description above
 */
private synchronized void pullFromZK(boolean isInit) {
  try {
    Stat stat = new Stat();
    byte[] bytes = client.getData().storingStatIn(stat).forPath(path);
    ByteBuffer bb = ByteBuffer.wrap(bytes);
    int dataVersion = bb.getInt();
    if (dataVersion > DATA_VERSION) {
      throw new IllegalStateException("Cannot load data from ZooKeeper; it"
              + "was written with a newer version");
    }
    int nextSecretLength = bb.getInt();
    byte[] nextSecret = new byte[nextSecretLength];
    bb.get(nextSecret);
    this.nextSecret = nextSecret;
    zkVersion = stat.getVersion();
    if (isInit) {
      int currentSecretLength = bb.getInt();
      byte[] currentSecret = new byte[currentSecretLength];
      bb.get(currentSecret);
      int previousSecretLength = bb.getInt();
      byte[] previousSecret = null;
      if (previousSecretLength > 0) {
        previousSecret = new byte[previousSecretLength];
        bb.get(previousSecret);
      }
      super.initSecrets(currentSecret, previousSecret);
      nextRolloverDate = bb.getLong();
    }
  } catch (Exception ex) {
    LOG.error("An unexpected exception occurred while pulling data from"
            + "ZooKeeper", ex);
  }
}
 

@Override
protected Scheduler scheduler() {

    final long guardLeasePeriodInMs = leasePeriodInMs / 4;

    return new AbstractScheduledService.CustomScheduler() {

        @Override
        protected Schedule getNextSchedule() throws Exception {
            if (!haveLease()) {
                // Get the current node version...
                Stat stat = zkClient.checkExists().forPath(leasePath);
                leaseNodeVersion = stat.getVersion();
                LOG.trace("{} will try to get lease (with Ver. {}) in {}ms", tsoHostAndPort, leaseNodeVersion,
                          leasePeriodInMs);
                // ...and wait the lease period
                return new Schedule(leasePeriodInMs, TimeUnit.MILLISECONDS);
            } else {
                long waitTimeInMs = getEndLeaseInMs() - System.currentTimeMillis() - guardLeasePeriodInMs;
                LOG.trace("{} will try to renew lease (with Ver. {}) in {}ms", tsoHostAndPort,
                          leaseNodeVersion, waitTimeInMs);
                return new Schedule(waitTimeInMs, TimeUnit.MILLISECONDS);
            }
        }
    };

}
 

/**
 * Pulls data from ZooKeeper.  If isInit is false, it will only parse the
 * next secret and version.  If isInit is true, it will also parse the current
 * and previous secrets, and the next rollover date; it will also init the
 * secrets.  Hence, isInit should only be true on startup.
 * @param isInit  see description above
 */
private synchronized void pullFromZK(boolean isInit) {
  try {
    Stat stat = new Stat();
    byte[] bytes = client.getData().storingStatIn(stat).forPath(path);
    ByteBuffer bb = ByteBuffer.wrap(bytes);
    int dataVersion = bb.getInt();
    if (dataVersion > DATA_VERSION) {
      throw new IllegalStateException("Cannot load data from ZooKeeper; it"
              + "was written with a newer version");
    }
    int nextSecretLength = bb.getInt();
    byte[] nextSecret = new byte[nextSecretLength];
    bb.get(nextSecret);
    this.nextSecret = nextSecret;
    zkVersion = stat.getVersion();
    if (isInit) {
      int currentSecretLength = bb.getInt();
      byte[] currentSecret = new byte[currentSecretLength];
      bb.get(currentSecret);
      int previousSecretLength = bb.getInt();
      byte[] previousSecret = null;
      if (previousSecretLength > 0) {
        previousSecret = new byte[previousSecretLength];
        bb.get(previousSecret);
      }
      super.initSecrets(currentSecret, previousSecret);
      nextRolloverDate = bb.getLong();
    }
  } catch (Exception ex) {
    LOG.error("An unexpected exception occurred while pulling data from"
            + "ZooKeeper", ex);
  }
}
 

private static MaxLogSegmentSequenceNo getMaxLogSegmentSequenceNo(ZooKeeperClient zkc, URI uri, String streamName,
                                                                  DistributedLogConfiguration conf) throws Exception {
    Stat stat = new Stat();
    String logSegmentsPath = ZKLogMetadata.getLogSegmentsPath(
            uri, streamName, conf.getUnpartitionedStreamName());
    byte[] data = zkc.get().getData(logSegmentsPath, false, stat);
    Versioned<byte[]> maxLSSNData = new Versioned<byte[]>(data, new ZkVersion(stat.getVersion()));
    return new MaxLogSegmentSequenceNo(maxLSSNData);
}
 

@Override
public void update(String path, T data, Stat stat) {
  String parentPath = HelixUtil.getZkParentPath(path);
  String childName = HelixUtil.getZkName(path);

  addToParentChildSet(parentPath, childName);
  ZNode znode = _cache.get(path);
  if (znode == null) {
    _cache.put(path, new ZNode(path, data, stat));
    fireEvents(path, EventType.NodeCreated);
  } else {
    Stat oldStat = znode.getStat();

    znode.setData(data);
    znode.setStat(stat);
    // System.out.println("\t\t--setData. path: " + path + ", data: " + data);

    if (oldStat.getCzxid() != stat.getCzxid()) {
      fireEvents(path, EventType.NodeDeleted);
      fireEvents(path, EventType.NodeCreated);
    } else if (oldStat.getVersion() != stat.getVersion()) {
      // System.out.println("\t--fireNodeChanged: " + path + ", oldVersion: " +
      // oldStat.getVersion() + ", newVersion: " + stat.getVersion());
      fireEvents(path, EventType.NodeDataChanged);
    }
  }
}
 

@Override
public long updateReloadTaskItemFlag(String taskType) throws Exception {
    String baseTaskType = ScheduleUtil.splitBaseTaskTypeFromTaskType(taskType);
    String zkPath = this.PATH_BaseTaskType + "/" + baseTaskType + "/" + taskType + "/" + this.PATH_Server;
    Stat stat = this.getZooKeeper().setData(zkPath, "reload=true".getBytes(), -1);
    return stat.getVersion();

}
 

public long getReloadTaskItemFlag(String taskType) throws Exception{
  	String baseTaskType = ScheduleUtil.splitBaseTaskTypeFromTaskType(taskType);
String zkPath = this.PATH_BaseTaskType + "/" + baseTaskType 
        + "/" + taskType + "/" + this.PATH_Server;
Stat stat = new Stat();
this.getZooKeeper().getData(zkPath, false, stat);
  	return stat.getVersion();
  }
 

/**
 * Create a rate limiter for a table.
 * @param tableNameWithType table name with table type.
 * @param brokerResource broker resource which stores all the broker states of each table.
 * @param quotaConfig quota config of the table.
 */
private void createRateLimiter(String tableNameWithType, ExternalView brokerResource, QuotaConfig quotaConfig) {
  if (quotaConfig == null || quotaConfig.getMaxQueriesPerSecond() == null) {
    LOGGER.info("No qps config specified for table: {}", tableNameWithType);
    return;
  }

  if (brokerResource == null) {
    LOGGER.warn("Failed to init qps quota for table {}. No broker resource connected!", tableNameWithType);
    return;
  }

  Map<String, String> stateMap = brokerResource.getStateMap(tableNameWithType);
  int otherOnlineBrokerCount = 0;

  // If stateMap is null, that means this broker is the first broker for this table.
  if (stateMap != null) {
    for (Map.Entry<String, String> state : stateMap.entrySet()) {
      if (!_helixManager.getInstanceName().equals(state.getKey()) && state.getValue()
          .equals(CommonConstants.Helix.StateModel.SegmentStateModel.ONLINE)) {
        otherOnlineBrokerCount++;
      }
    }
  }

  int onlineCount = otherOnlineBrokerCount + 1;
  LOGGER.info("The number of online brokers for table {} is {}", tableNameWithType, onlineCount);

  // Get the dynamic rate
  double overallRate = quotaConfig.getMaxQPS();

  // Get stat from property store
  String tableConfigPath = constructTableConfigPath(tableNameWithType);
  Stat stat = _propertyStore.getStat(tableConfigPath, AccessOption.PERSISTENT);

  double perBrokerRate = overallRate / onlineCount;
  QueryQuotaEntity queryQuotaEntity =
      new QueryQuotaEntity(RateLimiter.create(perBrokerRate), new HitCounter(TIME_RANGE_IN_SECOND), onlineCount,
          overallRate, stat.getVersion());
  _rateLimiterMap.put(tableNameWithType, queryQuotaEntity);
  LOGGER.info(
      "Rate limiter for table: {} has been initialized. Overall rate: {}. Per-broker rate: {}. Number of online broker instances: {}. Table config stat version: {}",
      tableNameWithType, overallRate, perBrokerRate, onlineCount, stat.getVersion());
}
 

/**
 * Process query quota change when number of online brokers has changed.
 */
public void processQueryQuotaChange(ExternalView currentBrokerResource) {
  LOGGER.info("Start processing qps quota change.");
  long startTime = System.currentTimeMillis();

  if (currentBrokerResource == null) {
    LOGGER.warn("Finish processing qps quota change: external view for broker resource is null!");
    return;
  }
  int currentVersionNumber = currentBrokerResource.getRecord().getVersion();
  if (currentVersionNumber == _lastKnownBrokerResourceVersion.get()) {
    LOGGER.info("No qps quota change: external view for broker resource remains the same.");
    return;
  }

  int numRebuilt = 0;
  for (Iterator<Map.Entry<String, QueryQuotaEntity>> it = _rateLimiterMap.entrySet().iterator(); it.hasNext(); ) {
    Map.Entry<String, QueryQuotaEntity> entry = it.next();
    String tableNameWithType = entry.getKey();
    QueryQuotaEntity queryQuotaEntity = entry.getValue();

    // Get number of online brokers.
    Map<String, String> stateMap = currentBrokerResource.getStateMap(tableNameWithType);
    if (stateMap == null) {
      LOGGER.info("No broker resource for Table {}. Removing its rate limit.", tableNameWithType);
      it.remove();
      continue;
    }
    int otherOnlineBrokerCount = 0;
    for (Map.Entry<String, String> state : stateMap.entrySet()) {
      if (!_helixManager.getInstanceName().equals(state.getKey()) && state.getValue()
          .equals(CommonConstants.Helix.StateModel.SegmentStateModel.ONLINE)) {
        otherOnlineBrokerCount++;
      }
    }
    int onlineBrokerCount = otherOnlineBrokerCount + 1;

    // Get stat from property store
    String tableConfigPath = constructTableConfigPath(tableNameWithType);
    Stat stat = _propertyStore.getStat(tableConfigPath, AccessOption.PERSISTENT);
    if (stat == null) {
      LOGGER.info("Table {} has been deleted from property store. Removing its rate limit.", tableNameWithType);
      it.remove();
      continue;
    }

    // If number of online brokers and table config don't change, there is no need to re-calculate the dynamic rate.
    if (onlineBrokerCount == queryQuotaEntity.getNumOnlineBrokers() && stat.getVersion() == queryQuotaEntity
        .getTableConfigStatVersion()) {
      continue;
    }

    double overallRate;
    // Get latest quota config only if stat don't match.
    if (stat.getVersion() != queryQuotaEntity.getTableConfigStatVersion()) {
      QuotaConfig quotaConfig = getQuotaConfigFromPropertyStore(tableNameWithType);
      if (quotaConfig == null || quotaConfig.getMaxQueriesPerSecond() == null) {
        LOGGER.info("No query quota config or the config is invalid for Table {}. Removing its rate limit.",
            tableNameWithType);
        it.remove();
        continue;
      }
      overallRate = quotaConfig.getMaxQPS();
    } else {
      overallRate = queryQuotaEntity.getOverallRate();
    }
    double latestRate = overallRate / onlineBrokerCount;
    double previousRate = queryQuotaEntity.getRateLimiter().getRate();
    if (Math.abs(latestRate - previousRate) > 0.001) {
      queryQuotaEntity.getRateLimiter().setRate(latestRate);
      queryQuotaEntity.setNumOnlineBrokers(onlineBrokerCount);
      queryQuotaEntity.setOverallRate(overallRate);
      queryQuotaEntity.setTableConfigStatVersion(stat.getVersion());
      LOGGER.info(
          "Rate limiter for table: {} has been updated. Overall rate: {}. Previous per-broker rate: {}. New per-broker rate: {}. Number of online broker instances: {}",
          tableNameWithType, overallRate, previousRate, latestRate, onlineBrokerCount);
      numRebuilt++;
    }
  }
  _lastKnownBrokerResourceVersion.set(currentVersionNumber);
  long endTime = System.currentTimeMillis();
  LOGGER
      .info("Processed query quota change in {}ms, {} out of {} query quota configs rebuilt.", (endTime - startTime),
          numRebuilt, _rateLimiterMap.size());
}
 

private TableSpaceList listTablesSpaces() throws KeeperException, InterruptedException, IOException {
    Stat stat = new Stat();
    List<String> children = ensureZooKeeper().getChildren(tableSpacesPath, mainWatcher, stat);
    return new TableSpaceList(stat.getVersion(), children);
}
 

public static void main(String[] args) throws Exception {
    // 创建节点
    String nodePath = "/testZK"; // 节点路径
    byte[] data = "this is a test data".getBytes(); // 节点数据
    byte[] newData = "new test data".getBytes(); // 节点数据

    // 设置重连策略ExponentialBackoffRetry, baseSleepTimeMs：初始sleep的时间,maxRetries：最大重试次数,maxSleepMs：最大重试时间
    RetryPolicy retryPolicy = new ExponentialBackoffRetry(10000, 5);
    //（推荐）curator链接zookeeper的策略:RetryNTimes n：重试的次数 sleepMsBetweenRetries：每次重试间隔的时间
    // RetryPolicy retryPolicy = new RetryNTimes(3, 5000);
    // （不推荐） curator链接zookeeper的策略:RetryOneTime sleepMsBetweenRetry:每次重试间隔的时间,这个策略只会重试一次
    // RetryPolicy retryPolicy2 = new RetryOneTime(3000);
    // 永远重试，不推荐使用
    // RetryPolicy retryPolicy3 = new RetryForever(retryIntervalMs)
    // curator链接zookeeper的策略:RetryUntilElapsed maxElapsedTimeMs:最大重试时间 sleepMsBetweenRetries:每次重试间隔 重试时间超过maxElapsedTimeMs后，就不再重试
    // RetryPolicy retryPolicy4 = new RetryUntilElapsed(2000, 3000);

    // Curator客户端
    CuratorFramework client = null;
    // 实例化Curator客户端，Curator的编程风格可以让我们使用方法链的形式完成客户端的实例化
    client = CuratorFrameworkFactory.builder()  // 使用工厂类来建造客户端的实例对象
            .connectString(zkServerIps) // 放入zookeeper服务器ip
            .sessionTimeoutMs(10000).retryPolicy(retryPolicy)  // 设定会话时间以及重连策略
            // .namespace("testApp")    // 隔离的命名空间
            .build(); // 建立连接通道
    // 启动Curator客户端
    client.start();

    boolean isZkCuratorStarted = client.getState().equals(CuratorFrameworkState.STARTED);
    System.out.println("当前客户端的状态：" + (isZkCuratorStarted ? "连接中..." : "已关闭..."));
    try {
        // 检查节点是否存在
        Stat s = client.checkExists().forPath(nodePath);
        if (s == null) {
            System.out.println("节点不存在，创建节点");
            // 创建节点
            String result = client.create()
                    .creatingParentsIfNeeded()    // 创建父节点，也就是会递归创建
                    .withMode(CreateMode.PERSISTENT) // 节点类型，PERSISTENT是持久节点
                    .withACL(ZooDefs.Ids.OPEN_ACL_UNSAFE) // 节点的ACL权限
                    .forPath(nodePath, data);
            System.out.println(result + "节点，创建成功...");
        } else {
            System.out.println("节点已存在，" + s);
        }
        getData(client, nodePath);  // 输出节点信息

        // 更新指定节点的数据
        int version = s == null ? 0 : s.getVersion();  // 版本不一致时的异常：KeeperErrorCode = BadVersion
        Stat resultStat = client.setData().withVersion(version)   // 指定数据版本
                .forPath(nodePath, newData);    // 需要修改的节点路径以及新数据
        System.out.println("更新节点数据成功");
        getData(client, nodePath);  // 输出节点信息

        // 删除节点
        client.delete().guaranteed()    // 如果删除失败，那么在后端还是会继续删除，直到成功
                .deletingChildrenIfNeeded() // 子节点也一并删除，也就是会递归删除
                .withVersion(resultStat.getVersion())
                .forPath(nodePath);
        System.out.println("删除节点：" + nodePath);
        Thread.sleep(1000);
    } finally {
        // 关闭客户端
        if (!client.getState().equals(CuratorFrameworkState.STOPPED)) {
            System.out.println("关闭客户端.....");
            client.close();
        }
        isZkCuratorStarted = client.getState().equals(CuratorFrameworkState.STARTED);
        System.out.println("当前客户端的状态：" + (isZkCuratorStarted ? "连接中..." : "已关闭..."));
    }
}
 

@Test(timeout = 60000)
public void testBadVersionOnTwoAllocators() throws Exception {
    String allocationPath = "/allocation-bad-version";
    zkc.get().create(allocationPath, new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
    Stat stat = new Stat();
    byte[] data = zkc.get().getData(allocationPath, false, stat);
    Versioned<byte[]> allocationData = new Versioned<byte[]>(data, new LongVersion(stat.getVersion()));

    SimpleLedgerAllocator allocator1 =
            new SimpleLedgerAllocator(allocationPath, allocationData, newQuorumConfigProvider(dlConf), zkc, bkc);
    SimpleLedgerAllocator allocator2 =
            new SimpleLedgerAllocator(allocationPath, allocationData, newQuorumConfigProvider(dlConf), zkc, bkc);
    allocator1.allocate();
    // wait until allocated
    ZKTransaction txn1 = newTxn();
    LedgerHandle lh = Utils.ioResult(allocator1.tryObtain(txn1, NULL_LISTENER));
    allocator2.allocate();
    ZKTransaction txn2 = newTxn();
    try {
        Utils.ioResult(allocator2.tryObtain(txn2, NULL_LISTENER));
        fail("Should fail allocating on second allocator as allocator1 is starting allocating something.");
    } catch (ZKException ke) {
        assertEquals(KeeperException.Code.BADVERSION, ke.getKeeperExceptionCode());
    }
    Utils.ioResult(txn1.execute());
    Utils.close(allocator1);
    Utils.close(allocator2);

    long eid = lh.addEntry("hello world".getBytes());
    lh.close();
    LedgerHandle readLh = bkc.get().openLedger(lh.getId(),
            BookKeeper.DigestType.CRC32, dlConf.getBKDigestPW().getBytes());
    Enumeration<LedgerEntry> entries = readLh.readEntries(eid, eid);
    int i = 0;
    while (entries.hasMoreElements()) {
        LedgerEntry entry = entries.nextElement();
        assertEquals("hello world", new String(entry.getEntry(), UTF_8));
        ++i;
    }
    assertEquals(1, i);
}