Examples with Watcher org.apache.zookeeper.Watcher used on opensource projects

Example 11 with Watcher

use of org.apache.zookeeper.Watcher in project zookeeper by apache.

the class QuorumZxidSyncTest method testLateLogs.

/**
     * find out what happens when the latest state is in the snapshots not
     * the logs.
     */
@Test
public void testLateLogs() throws Exception {
    // crank up the epoch numbers
    ClientBase.waitForServerUp(qb.hostPort, 10000);
    ClientBase.waitForServerUp(qb.hostPort, 10000);
    ZooKeeper zk = new ZooKeeper(qb.hostPort, 10000, new Watcher() {

        public void process(WatchedEvent event) {
        }
    });
    zk.create("/0", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
    zk.close();
    qb.shutdownServers();
    qb.startServers();
    ClientBase.waitForServerUp(qb.hostPort, 10000);
    qb.shutdownServers();
    qb.startServers();
    ClientBase.waitForServerUp(qb.hostPort, 10000);
    zk = new ZooKeeper(qb.hostPort, 10000, new Watcher() {

        public void process(WatchedEvent event) {
        }
    });
    zk.create("/1", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
    zk.close();
    qb.shutdownServers();
    qb.startServers();
    ClientBase.waitForServerUp(qb.hostPort, 10000);
    qb.shutdownServers();
    deleteLogs(qb.s1dir);
    deleteLogs(qb.s2dir);
    deleteLogs(qb.s3dir);
    deleteLogs(qb.s4dir);
    deleteLogs(qb.s5dir);
    qb.startServers();
    ClientBase.waitForServerUp(qb.hostPort, 10000);
    zk = new ZooKeeper(qb.hostPort, 10000, new Watcher() {

        public void process(WatchedEvent event) {
        }
    });
    zk.create("/2", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
    zk.close();
    qb.shutdownServers();
    qb.startServers();
    ClientBase.waitForServerUp(qb.hostPort, 10000);
    zk = new ZooKeeper(qb.hostPort, 10000, new Watcher() {

        public void process(WatchedEvent event) {
        }
    });
    boolean saw2 = false;
    for (String child : zk.getChildren("/", false)) {
        if (child.equals("2")) {
            saw2 = true;
        }
    }
    zk.close();
    Assert.assertTrue("Didn't see /2 (went back in time)", saw2);
}

Example 12 with Watcher

use of org.apache.zookeeper.Watcher in project weave by continuuity.

the class KillZKSession method kill.

/**
   * Kills a Zookeeper client to simulate failure scenarious during testing.
   * Callee will provide the amount of time to wait before it's considered failure
   * to kill a client.
   *
   * @param client that needs to be killed.
   * @param connectionString of Quorum
   * @param maxMs time in millisecond specifying the max time to kill a client.
   * @throws IOException When there is IO error
   * @throws InterruptedException When call has been interrupted.
   */
public static void kill(ZooKeeper client, String connectionString, int maxMs) throws IOException, InterruptedException {
    final CountDownLatch latch = new CountDownLatch(1);
    ZooKeeper zk = new ZooKeeper(connectionString, maxMs, new Watcher() {

        @Override
        public void process(WatchedEvent event) {
            if (event.getState() == Event.KeeperState.SyncConnected) {
                latch.countDown();
            }
        }
    }, client.getSessionId(), client.getSessionPasswd());
    try {
        Preconditions.checkState(latch.await(maxMs, TimeUnit.MILLISECONDS), "Fail to kill ZK connection.");
    } finally {
        zk.close();
    }
}

Example 13 with Watcher

use of org.apache.zookeeper.Watcher in project weave by continuuity.

the class ZKOperations method watchData.

/**
   * Watch for data changes of the given path. The callback will be triggered whenever changes has been
   * detected. Note that the callback won't see every single changes, as that's not the guarantee of ZooKeeper.
   * If the node doesn't exists, it will watch for its creation then starts watching for data changes.
   * When the node is deleted afterwards,
   *
   * @param zkClient The {@link ZKClient} for the operation
   * @param path Path to watch
   * @param callback Callback to be invoked when data changes is detected.
   * @return A {@link Cancellable} to cancel the watch.
   */
public static Cancellable watchData(final ZKClient zkClient, final String path, final DataCallback callback) {
    final AtomicBoolean cancelled = new AtomicBoolean(false);
    watchChanges(new Operation<NodeData>() {

        @Override
        public ZKClient getZKClient() {
            return zkClient;
        }

        @Override
        public OperationFuture<NodeData> exec(String path, Watcher watcher) {
            return zkClient.getData(path, watcher);
        }
    }, path, callback, cancelled);
    return new Cancellable() {

        @Override
        public void cancel() {
            cancelled.set(true);
        }
    };
}

Example 14 with Watcher

use of org.apache.zookeeper.Watcher in project weave by continuuity.

the class ZKOperations method watchChildren.

public static Cancellable watchChildren(final ZKClient zkClient, String path, ChildrenCallback callback) {
    final AtomicBoolean cancelled = new AtomicBoolean(false);
    watchChanges(new Operation<NodeChildren>() {

        @Override
        public ZKClient getZKClient() {
            return zkClient;
        }

        @Override
        public OperationFuture<NodeChildren> exec(String path, Watcher watcher) {
            return zkClient.getChildren(path, watcher);
        }
    }, path, callback, cancelled);
    return new Cancellable() {

        @Override
        public void cancel() {
            cancelled.set(true);
        }
    };
}

Example 15 with Watcher

use of org.apache.zookeeper.Watcher in project weave by continuuity.

the class ZKClientTest method testExpireRewatch.

@Test
public void testExpireRewatch() throws InterruptedException, IOException, ExecutionException {
    InMemoryZKServer zkServer = InMemoryZKServer.builder().setTickTime(1000).build();
    zkServer.startAndWait();
    try {
        final CountDownLatch expireReconnectLatch = new CountDownLatch(1);
        final AtomicBoolean expired = new AtomicBoolean(false);
        final ZKClientService client = ZKClientServices.delegate(ZKClients.reWatchOnExpire(ZKClientService.Builder.of(zkServer.getConnectionStr()).setSessionTimeout(2000).setConnectionWatcher(new Watcher() {

            @Override
            public void process(WatchedEvent event) {
                if (event.getState() == Event.KeeperState.Expired) {
                    expired.set(true);
                } else if (event.getState() == Event.KeeperState.SyncConnected && expired.compareAndSet(true, true)) {
                    expireReconnectLatch.countDown();
                }
            }
        }).build()));
        client.startAndWait();
        try {
            final BlockingQueue<Watcher.Event.EventType> events = new LinkedBlockingQueue<Watcher.Event.EventType>();
            client.exists("/expireRewatch", new Watcher() {

                @Override
                public void process(WatchedEvent event) {
                    client.exists("/expireRewatch", this);
                    events.add(event.getType());
                }
            });
            client.create("/expireRewatch", null, CreateMode.PERSISTENT);
            Assert.assertEquals(Watcher.Event.EventType.NodeCreated, events.poll(2, TimeUnit.SECONDS));
            KillZKSession.kill(client.getZooKeeperSupplier().get(), zkServer.getConnectionStr(), 1000);
            Assert.assertTrue(expireReconnectLatch.await(5, TimeUnit.SECONDS));
            client.delete("/expireRewatch");
            Assert.assertEquals(Watcher.Event.EventType.NodeDeleted, events.poll(4, TimeUnit.SECONDS));
        } finally {
            client.stopAndWait();
        }
    } finally {
        zkServer.stopAndWait();
    }
}