Java Code Examples for org.apache.zookeeper.Watcher.Event.KeeperState#Expired

private void processStateChanged(WatchedEvent event) {
    LOG.info("zookeeper state changed (" + event.getState() + ")");
    setCurrentState(event.getState());
    if (getShutdownTrigger()) {
        return;
    }
    fireStateChangedEvent(event.getState());
    if (event.getState() == KeeperState.Expired) {
        try {
            reconnect();
            fireNewSessionEvents();
        } catch (final Exception e) {
            LOG.info("Unable to re-establish connection. Notifying consumer of the following exception: ", e);
            fireSessionEstablishmentError(e);
        }
    }
}
 

@Override
public void process(WatchedEvent event) {

    LOGGER.debug("Got Event from ZooKeeper: " + event + " Connection state: " + event.getState());

    if (event.getState() == KeeperState.Expired) {
        previousState = KeeperState.Disconnected;
        goToSlaveMode();
        try {
            init();
        } catch (IOException | ClusterManagerException e) {
            LOGGER.error("Failed to init after session timeout", e);
        }
        return;
    }

    if (event.getState() != KeeperState.SyncConnected) {
        previousState = event.getState();
        goToSlaveMode();
        return;
    }

    handleStateChange(event);
}
 

private void processStateChanged(WatchedEvent event) {
    LOG.info("zookeeper state changed (" + event.getState() + ")");
    setCurrentState(event.getState());
    if (getShutdownTrigger()) {
        return;
    }
    fireStateChangedEvent(event.getState());
    if (event.getState() == KeeperState.Expired) {
        try {
            reconnect();
            fireNewSessionEvents();
        } catch (final Exception e) {
            LOG.info("Unable to re-establish connection. Notifying consumer of the following exception: ", e);
            fireSessionEstablishmentError(e);
        }
    }
}
 

public synchronized void process(WatchedEvent event) {
    LOG.info("Watcher " + name + " got event " + event);

    state = event.getState();
    if (state == KeeperState.SyncConnected) {
        connected = true;
        clientConnected.countDown();
    } else if (state == KeeperState.SaslAuthenticated) {
    } else {
        connected = false;
    }
    if (state == KeeperState.Expired) {
        expired = true;
    } else if (state == KeeperState.SaslAuthenticated) {
    } else {
        expired = false;
    }
    notifyAll();
}
 

private void processStateChanged(WatchedEvent event) {
    logger.info("zookeeper state changed (" + event.getState() + ")");
    setCurrentState(event.getState());
    if (getShutdownTrigger()) {
        return;
    }
    try {
        fireStateChangedEvent(event.getState());

        if (event.getState() == KeeperState.Expired) {
            reconnect();
            fireNewSessionEvents();
        }
    } catch (final Exception e) {
        throw new RuntimeException("Exception while restarting zk client", e);
    }
}
 

public synchronized void process(WatchedEvent event) {
    LOG.info("Watcher " + name + " got event " + event);

    state = event.getState();
    if (state == KeeperState.SyncConnected) {
        connected = true;
        clientConnected.countDown();
    } else {
        connected = false;
    }
    if (state == KeeperState.Expired) {
        expired = true;
    } else {
        expired = false;
    }
    notifyAll();
}
 

/**
 * Clients that need to re-establish state after session expiration can register an
 * {@code onExpired} command to execute.
 *
 * @param onExpired the {@code Command} to register
 * @return the new {@link Watcher} which can later be passed to {@link #unregister} for
 *         removal.
 */
public Watcher registerExpirationHandler(final ZooKeeperSessionExpireNotifier onExpired) {
    Watcher watcher = new Watcher() {
        @Override
        public void process(WatchedEvent event) {
            if (event.getType() == EventType.None && event.getState() == KeeperState.Expired) {
                try {
                    onExpired.notifySessionExpired();
                } catch (Exception exc) {
                    // do nothing
                }
            }
        }
    };
    register(watcher);
    return watcher;
}
 

/**
 * Clients that need to re-establish state after session expiration can register an
 * {@code onExpired} command to execute.
 *
 * @param onExpired the {@code Command} to register
 * @return the new {@link Watcher} which can later be passed to {@link #unregister} for
 *         removal.
 */
public Watcher registerExpirationHandler(final ZooKeeperSessionExpireNotifier onExpired) {
    Watcher watcher = new Watcher() {
        @Override
        public void process(WatchedEvent event) {
            if (event.getType() == EventType.None && event.getState() == KeeperState.Expired) {
                try {
                    onExpired.notifySessionExpired();
                } catch (Exception exc) {
                    // do nothing
                }
            }
        }
    };
    register(watcher);
    return watcher;
}
 

@Test
public void testProcess1() {
    WatchedEvent event = new WatchedEvent(EventType.None, KeeperState.Expired, null);
    sessionWatcher.process(event);
    assertTrue(sessionWatcher.isShutdownStarted());
    assertEquals(shutdownService.getExitCode(), -1);
}
 

private void sessionEvent(CountDownLatch connectionLatch, WatchedEvent event) {
  if (event.getState() == KeeperState.SyncConnected) {
    LOG.info("收到ZK连接成功事件！");
    connectionLatch.countDown();
  } else if (event.getState() == KeeperState.Expired) {
    LOG.error("会话超时，等待重新建立ZK连接...");
    try {
      reConnection();
    } catch (Exception e) {
      LOG.error(e.getMessage(), e);
    }
  } // Disconnected：Zookeeper会自动处理Disconnected状态重连
}
 

@Test
public void testProcess3() {
    WatchedEvent event = new WatchedEvent(EventType.NodeCreated, KeeperState.Expired, null);
    sessionWatcher.process(event);
    assertFalse(sessionWatcher.isShutdownStarted());
    assertEquals(shutdownService.getExitCode(), 0);
}
 

private void sessionEvent(CountDownLatch connectionLatch, WatchedEvent event) {
    if (event.getState() == KeeperState.SyncConnected) {
        log.info("收到ZK连接成功事件！");
        connectionLatch.countDown();
    } else if (event.getState() == KeeperState.Expired) {
        log.error("会话超时，等待重新建立ZK连接...");
        try {
            reConnection();
        } catch (Exception e) {
            log.error(e.getMessage(),e);
        }
    } // Disconnected：Zookeeper会自动处理Disconnected状态重连
}
 

@Override
public void process(WatchedEvent event) {
    LOG.debug("Received event: " + event);
    _zookeeperEventThread = Thread.currentThread();

    boolean stateChanged = event.getPath() == null;
    boolean znodeChanged = event.getPath() != null;
    boolean dataChanged = event.getType() == EventType.NodeDataChanged || event.getType() == EventType.NodeDeleted || event.getType() == EventType.NodeCreated
            || event.getType() == EventType.NodeChildrenChanged;

    getEventLock().lock();
    try {

        // We might have to install child change event listener if a new node was created
        if (getShutdownTrigger()) {
            LOG.debug("ignoring event '{" + event.getType() + " | " + event.getPath() + "}' since shutdown triggered");
            return;
        }
        if (stateChanged) {
            processStateChanged(event);
        }
        if (dataChanged) {
            processDataOrChildChange(event);
        }
    } finally {
        if (stateChanged) {
            getEventLock().getStateChangedCondition().signalAll();

            // If the session expired we have to signal all conditions, because watches might have been removed and
            // there is no guarantee that those
            // conditions will be signaled at all after an Expired event
            if (event.getState() == KeeperState.Expired) {
                getEventLock().getZNodeEventCondition().signalAll();
                getEventLock().getDataChangedCondition().signalAll();
                // We also have to notify all listeners that something might have changed
                fireAllEvents();
            }
        }
        if (znodeChanged) {
            getEventLock().getZNodeEventCondition().signalAll();
        }
        if (dataChanged) {
            getEventLock().getDataChangedCondition().signalAll();
        }
        getEventLock().unlock();
        LOG.debug("Leaving process event");
    }
}
 

/**
 * 事件处理
 * @see org.apache.zookeeper.Watcher#process(org.apache.zookeeper.WatchedEvent)
 */
@Override
public void process(WatchedEvent event) {
    LOG.debug("ZooKeeper event is arrived [" + event+" ]...");
    EventType eventType = event.getType();
    //状态更新
    boolean stateChanged = event.getPath() == null;
    //节点相关的所有事件
    boolean znodeChanged = event.getPath() != null;
    
    //节点创建、删除和数据改变的事件
    boolean nodeChanged = eventType == EventType.NodeDataChanged 
            || eventType == EventType.NodeDeleted 
            || eventType == EventType.NodeCreated;
    
    //子节点数量改变相关的事件，包括节点创建和删除（都会影响子节点数量的变化），以及子节点数量的改变
    boolean childChanged = eventType == EventType.NodeDeleted 
            || eventType == EventType.NodeCreated
            || eventType == EventType.NodeChildrenChanged;
    
    client.acquireEventLock();
    try {
        if (client.getShutdownTrigger()) {
            LOG.debug("client will shutdown,ignore the event [" + eventType + " | " + event.getPath() + "]");
            return;
        }
        if (stateChanged) {//ZooKeeper状态改变的处理
            process.processStateChanged(event);
        }
        if (nodeChanged) {//节点改变事件处理，包括节点的创建、删除、数据改变
            process.processNodeChanged(event);
        }
        if (childChanged) {//造成子节点数量改变的事件的处理，包括节点的创建、删除、子节点数量改变
            process.processChildChanged(event);
        }
    } finally {
        if (stateChanged) {
            client.getEventLock().getStateChangedCondition().signalAll();
            // 在会话失效后，服务端会取消watch.
            // 如果在会话失效后与重连这段时间内有数据发生变化，监听器是无法监听到的，
            // 所以要唤醒等待的监听，并触发所有的监听事件
            if (event.getState() == KeeperState.Expired) {
                client.getEventLock().getNodeEventCondition().signalAll();
                client.getEventLock().getNodeOrChildChangedCondition().signalAll();
                
                // 通知所有的监听器，可能存在数据变化
                process.processAllNodeAndChildListeners(event);
            }
        }
        if (znodeChanged) {
            client.getEventLock().getNodeEventCondition().signalAll();
        }
        if (nodeChanged || childChanged) {
            client.getEventLock().getNodeOrChildChangedCondition().signalAll();
        }
        client.releaseEventLock();
    }
}
 

public void process(WatchedEvent event) {
    logger.debug("Received event: " + event);
    _zookeeperEventThread = Thread.currentThread();

    boolean stateChanged = event.getPath() == null;
    boolean znodeChanged = event.getPath() != null;
    boolean dataChanged = event.getType() == EventType.NodeDataChanged || //
                    event.getType() == EventType.NodeDeleted || event.getType() == EventType.NodeCreated || //
                    event.getType() == EventType.NodeChildrenChanged;

    getEventLock().lock();
    try {

        // We might have to install child change event listener if a new node was created
        if (getShutdownTrigger()) {
            logger.debug("ignoring event '{" + event.getType() + " | " + event.getPath() + "}' since shutdown triggered");
            return;
        }
        if (stateChanged) {
            processStateChanged(event);
        }
        if (dataChanged) {
            processDataOrChildChange(event);
        }
    } finally {
        if (stateChanged) {
            getEventLock().getStateChangedCondition().signalAll();

            // If the session expired we have to signal all conditions, because watches might have been removed and
            // there is no guarantee that those
            // conditions will be signaled at all after an Expired event
            if (event.getState() == KeeperState.Expired) {
                getEventLock().getZNodeEventCondition().signalAll();
                getEventLock().getDataChangedCondition().signalAll();
                // We also have to notify all listeners that something might have changed
                fireAllEvents();
            }
        }
        if (znodeChanged) {
            getEventLock().getZNodeEventCondition().signalAll();
        }
        if (dataChanged) {
            getEventLock().getDataChangedCondition().signalAll();
        }
        getEventLock().unlock();
        logger.debug("Leaving process event");
    }
}
 

@Override
public void process(WatchedEvent event) {
    LOG.debug("Received event: " + event);
    _zookeeperEventThread = Thread.currentThread();

    boolean stateChanged = event.getPath() == null;
    boolean znodeChanged = event.getPath() != null;
    boolean dataChanged = event.getType() == EventType.NodeDataChanged || event.getType() == EventType.NodeDeleted || event.getType() == EventType.NodeCreated
            || event.getType() == EventType.NodeChildrenChanged;

    getEventLock().lock();
    try {

        // We might have to install child change event listener if a new node was created
        if (getShutdownTrigger()) {
            LOG.debug("ignoring event '{" + event.getType() + " | " + event.getPath() + "}' since shutdown triggered");
            return;
        }
        if (stateChanged) {
            processStateChanged(event);
        }
        if (dataChanged) {
            processDataOrChildChange(event);
        }
    } finally {
        if (stateChanged) {
            getEventLock().getStateChangedCondition().signalAll();

            // If the session expired we have to signal all conditions, because watches might have been removed and
            // there is no guarantee that those
            // conditions will be signaled at all after an Expired event
            if (event.getState() == KeeperState.Expired) {
                getEventLock().getZNodeEventCondition().signalAll();
                getEventLock().getDataChangedCondition().signalAll();
                // We also have to notify all listeners that something might have changed
                fireAllEvents();
            }
        }
        if (znodeChanged) {
            getEventLock().getZNodeEventCondition().signalAll();
        }
        if (dataChanged) {
            getEventLock().getDataChangedCondition().signalAll();
        }
        getEventLock().unlock();
        LOG.debug("Leaving process event");
    }
}
 

@Override
public void process(WatchedEvent event) {
  long notificationTime = System.currentTimeMillis();
  if (LOG.isDebugEnabled()) {
    LOG.debug("Received event: " + event);
  }
  _zookeeperEventThread = Thread.currentThread();

  boolean stateChanged = event.getPath() == null;
  boolean sessionExpired = stateChanged && event.getState() == KeeperState.Expired;
  boolean znodeChanged = event.getPath() != null;
  boolean dataChanged =
      event.getType() == EventType.NodeDataChanged || event.getType() == EventType.NodeDeleted
          || event.getType() == EventType.NodeCreated
          || event.getType() == EventType.NodeChildrenChanged;
  if (event.getType() == EventType.NodeDeleted) {
    LOG.debug("Path {} is deleted", event.getPath());
  }

  getEventLock().lock();
  try {
    // We might have to install child change event listener if a new node was created
    if (getShutdownTrigger()) {
      if (LOG.isDebugEnabled()) {
        LOG.debug("ignoring event '{" + event.getType() + " | " + event.getPath()
            + "}' since shutdown triggered");
      }
      return;
    }
    if (stateChanged) {
      processStateChanged(event);
    }
    if (dataChanged) {
      processDataOrChildChange(event, notificationTime);
    }
  } finally {
    if (stateChanged) {
      getEventLock().getStateChangedCondition().signalAll();

      // If the session expired we have to signal all conditions, because watches might have been
      // removed and
      // there is no guarantee that those
      // conditions will be signaled at all after an Expired event
      // TODO PVo write a test for this
      if (event.getState() == KeeperState.Expired) {
        getEventLock().getZNodeEventCondition().signalAll();
        getEventLock().getDataChangedCondition().signalAll();
      }
    }
    if (znodeChanged) {
      getEventLock().getZNodeEventCondition().signalAll();
    }
    if (dataChanged) {
      getEventLock().getDataChangedCondition().signalAll();
    }
    getEventLock().unlock();

    // update state change counter.
    recordStateChange(stateChanged, dataChanged, sessionExpired);

    if (LOG.isDebugEnabled()) {
      LOG.debug("Leaving process event");
    }
  }
}
 

protected void processStateChanged(WatchedEvent event) {
  LOG.info("zookeeper state changed (" + event.getState() + ")");
  setCurrentState(event.getState());
  if (getShutdownTrigger()) {
    return;
  }

  fireStateChangedEvent(event.getState());

  /*
   *  Note, the intention is that only the ZkClient managing the session would do auto reconnect
   *  and fireNewSessionEvents and fireAllEvent.
   *  Other ZkClient not managing the session would only fireAllEvent upon a new session.
   */
  if (event.getState() == KeeperState.SyncConnected) {
    if (!_isNewSessionEventFired && !"0".equals(getHexSessionId())) {
      /*
       * Before the new zookeeper instance is connected to the zookeeper service and its session
       * is established, its session id is 0.
       * New session event is not fired until the new zookeeper session receives the first
       * SyncConnected state(the zookeeper session is established).
       * Now the session id is available and non-zero, and we can fire new session events.
       */
      fireNewSessionEvents();

      /*
       * Set it true to avoid firing events again for the same session next time
       * when SyncConnected events are received.
       */
      _isNewSessionEventFired = true;

      /*
       * With this first SyncConnected state, we just get connected to zookeeper service after
       * reconnecting when the session expired. Because previous session expired, we also have to
       * notify all listeners that something might have changed.
       */
      fireAllEvents();
    }
  } else if (event.getState() == KeeperState.Expired) {
    _isNewSessionEventFired = false;
    reconnectOnExpiring();
  }
}
 

/**
 * 回调函数
 */
@Override
public void process(WatchedEvent event) {

    //
    // 结点更新时
    //
    if (event.getType() == EventType.NodeDataChanged) {

        try {

            LOGGER.info("============GOT UPDATE EVENT " + event.toString() + ": (" + monitorPath + "," + keyName
                    + "," + disConfigTypeEnum.getModelName() + ")======================");

            // 调用回调函数, 回调函数里会重新进行监控
            callback();

        } catch (Exception e) {

            LOGGER.error("monitor node exception. " + monitorPath, e);
        }
    }

    //
    // 结点断开连接，这时不要进行处理
    //
    if (event.getState() == KeeperState.Disconnected) {

        if (!debug) {
            LOGGER.warn("============GOT Disconnected EVENT " + event.toString() + ": (" + monitorPath + ","
                    + keyName + "," + disConfigTypeEnum.getModelName() + ")======================");
        } else {
            LOGGER.debug("============DEBUG MODE: GOT Disconnected EVENT " + event.toString() + ": (" +
                    monitorPath +
                    "," +
                    keyName +
                    "," + disConfigTypeEnum.getModelName() + ")======================");
        }
    }

    //
    // session expired，需要重新关注哦
    //
    if (event.getState() == KeeperState.Expired) {

        if (!debug) {

            LOGGER.error("============GOT Expired  " + event.toString() + ": (" + monitorPath + "," + keyName
                    + "," + disConfigTypeEnum.getModelName() + ")======================");

            // 重新连接
            ZookeeperMgr.getInstance().reconnect();

            callback();
        } else {
            LOGGER.debug("============DEBUG MODE: GOT Expired  " + event.toString() + ": (" + monitorPath + ","
                    + "" + keyName + "," + disConfigTypeEnum.getModelName() + ")======================");
        }
    }
}
 

/**
 * 回调函数
 */
@Override
public void process(WatchedEvent event) {

    //
    // 结点更新时
    //
    if (event.getType() == EventType.NodeDataChanged) {

        try {

            LOGGER.info("============GOT UPDATE EVENT " + event.toString() + ": (" + monitorPath + "," + keyName
                    + "," + disConfigTypeEnum.getModelName() + ")======================");

            // 调用回调函数, 回调函数里会重新进行监控
            callback();

        } catch (Exception e) {

            LOGGER.error("monitor node exception. " + monitorPath, e);
        }
    }

    //
    // 结点断开连接，这时不要进行处理
    //
    if (event.getState() == KeeperState.Disconnected) {

        if (!debug) {
            LOGGER.warn("============GOT Disconnected EVENT " + event.toString() + ": (" + monitorPath + ","
                    + keyName + "," + disConfigTypeEnum.getModelName() + ")======================");
        } else {
            LOGGER.debug("============DEBUG MODE: GOT Disconnected EVENT " + event.toString() + ": (" +
                    monitorPath +
                    "," +
                    keyName +
                    "," + disConfigTypeEnum.getModelName() + ")======================");
        }
    }

    //
    // session expired，需要重新关注哦
    //
    if (event.getState() == KeeperState.Expired) {

        if (!debug) {

            LOGGER.error("============GOT Expired  " + event.toString() + ": (" + monitorPath + "," + keyName
                    + "," + disConfigTypeEnum.getModelName() + ")======================");

            // 重新连接
            ZookeeperMgr.getInstance().reconnect();

            callback();
        } else {
            LOGGER.debug("============DEBUG MODE: GOT Expired  " + event.toString() + ": (" + monitorPath + ","
                    + "" + keyName + "," + disConfigTypeEnum.getModelName() + ")======================");
        }
    }
}