Example usage for org.apache.zookeeper WatchedEvent getState

List of usage examples for org.apache.zookeeper WatchedEvent getState

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Introduction

In this page you can find the example usage for org.apache.zookeeper WatchedEvent getState.

Prototype

public KeeperState getState()

Source Link

Usage

From source file:org.apache.hadoop.contrib.bkjournal.TestBookKeeperConfiguration.java

License:Apache License

private static ZooKeeper connectZooKeeper(String ensemble)
        throws IOException, KeeperException, InterruptedException {
    final CountDownLatch latch = new CountDownLatch(1);

    ZooKeeper zkc = new ZooKeeper(HOSTPORT, ZK_SESSION_TIMEOUT, new Watcher() {
        public void process(WatchedEvent event) {
            if (event.getState() == Watcher.Event.KeeperState.SyncConnected) {
                latch.countDown();/*  w  ww. j  a va  2  s  .  c  o m*/
            }
        }
    });
    if (!latch.await(ZK_SESSION_TIMEOUT, TimeUnit.MILLISECONDS)) {
        throw new IOException("Zookeeper took too long to connect");
    }
    return zkc;
}

From source file:org.apache.hadoop.contrib.bkjournal.TestCurrentInprogress.java

License:Apache License

private static ZooKeeper connectZooKeeper(String ensemble)
        throws IOException, KeeperException, InterruptedException {
    final CountDownLatch latch = new CountDownLatch(1);

    ZooKeeper zkc = new ZooKeeper(HOSTPORT, 3600, new Watcher() {
        public void process(WatchedEvent event) {
            if (event.getState() == Watcher.Event.KeeperState.SyncConnected) {
                latch.countDown();//  w  ww.j ava2 s .  c o  m
            }
        }
    });
    if (!latch.await(10, TimeUnit.SECONDS)) {
        throw new IOException("Zookeeper took too long to connect");
    }
    return zkc;
}

From source file:org.apache.hadoop.contrib.bkjournal.WriteLock.java

License:Apache License

public void process(WatchedEvent event) {
    if (event.getState() == KeeperState.Disconnected || event.getState() == KeeperState.Expired) {
        LOG.warn("Lost zookeeper session, lost lock ");
        lockCount.set(0);/* w  w  w. j a  v  a 2s .  com*/
    } else {
        // reapply the watch
        synchronized (this) {
            LOG.info("Zookeeper event " + event + " received, reapplying watch to " + myznode);
            if (myznode != null) {
                try {
                    zkc.exists(myznode, this);
                } catch (Exception e) {
                    LOG.warn("Could not set watch on lock, releasing", e);
                    try {
                        release();
                    } catch (IOException ioe) {
                        LOG.error("Could not release Zk lock", ioe);
                    }
                }
            }
        }
    }
}

From source file:org.apache.hadoop.ha.ActiveStandbyElector.java

License:Apache License

/**
 * interface implementation of Zookeeper watch events (connection and node),
 * proxied by {@link WatcherWithClientRef}.
 */// ww  w .  j a va2 s. co m
synchronized void processWatchEvent(ZooKeeper zk, WatchedEvent event) {
    Event.EventType eventType = event.getType();
    if (isStaleClient(zk))
        return;
    LOG.debug("Watcher event type: " + eventType + " with state:" + event.getState() + " for path:"
            + event.getPath() + " connectionState: " + zkConnectionState + " for " + this);

    if (eventType == Event.EventType.None) {
        // the connection state has changed
        switch (event.getState()) {
        case SyncConnected:
            LOG.info("Session connected.");
            // if the listener was asked to move to safe state then it needs to
            // be undone
            ConnectionState prevConnectionState = zkConnectionState;
            zkConnectionState = ConnectionState.CONNECTED;
            if (prevConnectionState == ConnectionState.DISCONNECTED && wantToBeInElection) {
                monitorActiveStatus();
            }
            break;
        case Disconnected:
            LOG.info("Session disconnected. Entering neutral mode...");

            // ask the app to move to safe state because zookeeper connection
            // is not active and we dont know our state
            zkConnectionState = ConnectionState.DISCONNECTED;
            enterNeutralMode();
            break;
        case Expired:
            // the connection got terminated because of session timeout
            // call listener to reconnect
            LOG.info("Session expired. Entering neutral mode and rejoining...");
            enterNeutralMode();
            reJoinElection(0);
            break;
        case SaslAuthenticated:
            LOG.info("Successfully authenticated to ZooKeeper using SASL.");
            break;
        default:
            fatalError("Unexpected Zookeeper watch event state: " + event.getState());
            break;
        }

        return;
    }

    // a watch on lock path in zookeeper has fired. so something has changed on
    // the lock. ideally we should check that the path is the same as the lock
    // path but trusting zookeeper for now
    String path = event.getPath();
    if (path != null) {
        switch (eventType) {
        case NodeDeleted:
            if (state == State.ACTIVE) {
                enterNeutralMode();
            }
            joinElectionInternal();
            break;
        case NodeDataChanged:
            monitorActiveStatus();
            break;
        default:
            LOG.debug("Unexpected node event: " + eventType + " for path: " + path);
            monitorActiveStatus();
        }

        return;
    }

    // some unexpected error has occurred
    fatalError("Unexpected watch error from Zookeeper");
}

From source file:org.apache.hadoop.ha.TestActiveStandbyElector.java

License:Apache License

/**
 * verify behavior of watcher.process callback with non-node event
 *///from   w  w  w. ja  v a2  s . c  om
@Test
public void testProcessCallbackEventNone() throws Exception {
    mockNoPriorActive();
    elector.joinElection(data);

    WatchedEvent mockEvent = Mockito.mock(WatchedEvent.class);
    Mockito.when(mockEvent.getType()).thenReturn(Event.EventType.None);

    // first SyncConnected should not do anything
    Mockito.when(mockEvent.getState()).thenReturn(Event.KeeperState.SyncConnected);
    elector.processWatchEvent(mockZK, mockEvent);
    Mockito.verify(mockZK, Mockito.times(0)).exists(Mockito.anyString(), Mockito.anyBoolean(),
            Mockito.<AsyncCallback.StatCallback>anyObject(), Mockito.<Object>anyObject());

    // disconnection should enter safe mode
    Mockito.when(mockEvent.getState()).thenReturn(Event.KeeperState.Disconnected);
    elector.processWatchEvent(mockZK, mockEvent);
    Mockito.verify(mockApp, Mockito.times(1)).enterNeutralMode();

    // re-connection should monitor master status
    Mockito.when(mockEvent.getState()).thenReturn(Event.KeeperState.SyncConnected);
    elector.processWatchEvent(mockZK, mockEvent);
    verifyExistCall(1);

    // session expired should enter safe mode and initiate re-election
    // re-election checked via checking re-creation of new zookeeper and
    // call to create lock znode
    Mockito.when(mockEvent.getState()).thenReturn(Event.KeeperState.Expired);
    elector.processWatchEvent(mockZK, mockEvent);
    // already in safe mode above. should not enter safe mode again
    Mockito.verify(mockApp, Mockito.times(1)).enterNeutralMode();
    // called getNewZooKeeper to create new session. first call was in
    // constructor
    Assert.assertEquals(2, count);
    // once in initial joinElection and one now
    Mockito.verify(mockZK, Mockito.times(2)).create(ZK_LOCK_NAME, data, Ids.OPEN_ACL_UNSAFE,
            CreateMode.EPHEMERAL, elector, mockZK);

    // create znode success. become master and monitor
    elector.processResult(Code.OK.intValue(), ZK_LOCK_NAME, mockZK, ZK_LOCK_NAME);
    Mockito.verify(mockApp, Mockito.times(1)).becomeActive();
    verifyExistCall(2);

    // error event results in fatal error
    Mockito.when(mockEvent.getState()).thenReturn(Event.KeeperState.AuthFailed);
    elector.processWatchEvent(mockZK, mockEvent);
    Mockito.verify(mockApp, Mockito.times(1))
            .notifyFatalError("Unexpected Zookeeper watch event state: AuthFailed");
    // only 1 state change callback is called at a time
    Mockito.verify(mockApp, Mockito.times(1)).enterNeutralMode();
}

From source file:org.apache.hadoop.ha.TestActiveStandbyElector.java

License:Apache License

/**
 * joinElection(..) should happen only after SERVICE_HEALTHY.
 *///from   w  w w.  j  a v a 2 s .  c  o m
@Test
public void testBecomeActiveBeforeServiceHealthy() throws Exception {
    mockNoPriorActive();
    WatchedEvent mockEvent = Mockito.mock(WatchedEvent.class);
    Mockito.when(mockEvent.getType()).thenReturn(Event.EventType.None);
    // session expired should enter safe mode
    // But for first time, before the SERVICE_HEALTY i.e. appData is set,
    // should not enter the election.
    Mockito.when(mockEvent.getState()).thenReturn(Event.KeeperState.Expired);
    elector.processWatchEvent(mockZK, mockEvent);
    // joinElection should not be called.
    Mockito.verify(mockZK, Mockito.times(0)).create(ZK_LOCK_NAME, null, Ids.OPEN_ACL_UNSAFE,
            CreateMode.EPHEMERAL, elector, mockZK);
}

From source file:org.apache.hadoop.hbase.stargate.RESTServlet.java

License:Apache License

@Override
public void process(WatchedEvent event) {
    LOG.debug(("ZooKeeper.Watcher event " + event.getType() + " with path " + event.getPath()));
    // handle disconnection (or manual delete to test disconnection scenario)
    if (event.getState() == KeeperState.Expired
            || (event.getType().equals(EventType.NodeDeleted) && event.getPath().equals(znode))) {
        wrapper.close();/*from w w  w .  j  a v  a2s  . com*/
        wrapper = null;
        while (!stopping.get())
            try {
                wrapper = initZooKeeperWrapper();
                break;
            } catch (IOException e) {
                LOG.error(StringUtils.stringifyException(e));
                try {
                    Thread.sleep(10 * 1000);
                } catch (InterruptedException ex) {
                }
            }
    }
}

From source file:org.apache.hadoop.hbase.zookeeper.ZKWatcher.java

License:Apache License

/**
 * Method called from ZooKeeper for events and connection status.
 * <p>/*  ww  w . j  a va  2  s.com*/
 * Valid events are passed along to listeners.  Connection status changes
 * are dealt with locally.
 */
@Override
public void process(WatchedEvent event) {
    LOG.debug(prefix("Received ZooKeeper Event, " + "type=" + event.getType() + ", " + "state="
            + event.getState() + ", " + "path=" + event.getPath()));

    switch (event.getType()) {

    // If event type is NONE, this is a connection status change
    case None: {
        connectionEvent(event);
        break;
    }

    // Otherwise pass along to the listeners

    case NodeCreated: {
        for (ZKListener listener : listeners) {
            listener.nodeCreated(event.getPath());
        }
        break;
    }

    case NodeDeleted: {
        for (ZKListener listener : listeners) {
            listener.nodeDeleted(event.getPath());
        }
        break;
    }

    case NodeDataChanged: {
        for (ZKListener listener : listeners) {
            listener.nodeDataChanged(event.getPath());
        }
        break;
    }

    case NodeChildrenChanged: {
        for (ZKListener listener : listeners) {
            listener.nodeChildrenChanged(event.getPath());
        }
        break;
    }
    default:
        throw new IllegalStateException("Received event is not valid: " + event.getState());
    }
}

From source file:org.apache.hadoop.hbase.zookeeper.ZKWatcher.java

License:Apache License

/**
 * Called when there is a connection-related event via the Watcher callback.
 * <p>/* w  ww  . j a va  2s .  c o  m*/
 * If Disconnected or Expired, this should shutdown the cluster. But, since
 * we send a KeeperException.SessionExpiredException along with the abort
 * call, it's possible for the Abortable to catch it and try to create a new
 * session with ZooKeeper. This is what the client does in HCM.
 * <p>
 * @param event the connection-related event
 */
private void connectionEvent(WatchedEvent event) {
    switch (event.getState()) {
    case SyncConnected:
        this.identifier = this.prefix + "-0x" + Long.toHexString(this.recoverableZooKeeper.getSessionId());
        // Update our identifier.  Otherwise ignore.
        LOG.debug(this.identifier + " connected");
        break;

    // Abort the server if Disconnected or Expired
    case Disconnected:
        LOG.debug(prefix("Received Disconnected from ZooKeeper, ignoring"));
        break;

    case Expired:
        String msg = prefix(this.identifier + " received expired from " + "ZooKeeper, aborting");
        // TODO: One thought is to add call to ZKListener so say,
        // ZKNodeTracker can zero out its data values.
        if (this.abortable != null) {
            this.abortable.abort(msg, new KeeperException.SessionExpiredException());
        }
        break;

    case ConnectedReadOnly:
    case SaslAuthenticated:
    case AuthFailed:
        break;

    default:
        throw new IllegalStateException("Received event is not valid: " + event.getState());
    }
}

From source file:org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher.java

License:Apache License

/**
 * Called when there is a connection-related event via the Watcher callback.
 * <p>/*from w w w  .  ja  va 2s.  co  m*/
 * If Disconnected or Expired, this should shutdown the cluster. But, since
 * we send a KeeperException.SessionExpiredException along with the abort
 * call, it's possible for the Abortable to catch it and try to create a new
 * session with ZooKeeper. This is what the client does in HCM.
 * <p>
 * @param event
 */
private void connectionEvent(WatchedEvent event) {
    switch (event.getState()) {
    case SyncConnected:
        // Now, this callback can be invoked before the this.zookeeper is set.
        // Wait a little while.
        long finished = System.currentTimeMillis()
                + this.conf.getLong("hbase.zookeeper.watcher.sync.connected.wait", 2000);
        while (System.currentTimeMillis() < finished) {
            try {
                Thread.sleep(1);
            } catch (InterruptedException e) {
                LOG.warn("Interrupted while sleeping");
                throw new RuntimeException("Interrupted while waiting for" + " recoverableZooKeeper is set");
            }
            if (this.recoverableZooKeeper != null)
                break;
        }

        if (this.recoverableZooKeeper == null) {
            LOG.error(
                    "ZK is null on connection event -- see stack trace "
                            + "for the stack trace when constructor was called on this zkw",
                    this.constructorCaller);
            throw new NullPointerException("ZK is null");
        }
        this.identifier = this.prefix + "-0x" + Long.toHexString(this.recoverableZooKeeper.getSessionId());
        // Update our identifier.  Otherwise ignore.
        LOG.debug(this.identifier + " connected");
        break;

    // Abort the server if Disconnected or Expired
    case Disconnected:
        LOG.debug(prefix("Received Disconnected from ZooKeeper, ignoring"));
        break;

    case Expired:
        String msg = prefix(this.identifier + " received expired from " + "ZooKeeper, aborting");
        // TODO: One thought is to add call to ZooKeeperListener so say,
        // ZooKeeperNodeTracker can zero out its data values.
        if (this.abortable != null) {
            this.abortable.abort(msg, new KeeperException.SessionExpiredException());
        }
        break;

    case ConnectedReadOnly:
    case SaslAuthenticated:
    case AuthFailed:
        break;

    default:
        throw new IllegalStateException("Received event is not valid: " + event.getState());
    }
}