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

Example 51 with Watcher

use of org.apache.zookeeper.Watcher in project rest.li by linkedin.

the class SymlinkAwareZooKeeperTest method testSymlinkWithExistWatch3.

@Test
public void testSymlinkWithExistWatch3() throws InterruptedException, ExecutionException {
    final CountDownLatch latch = new CountDownLatch(1);
    final CountDownLatch latch2 = new CountDownLatch(1);
    final AsyncCallback.StatCallback existCallback = new AsyncCallback.StatCallback() {

        @Override
        public void processResult(int rc, String path, Object ctx, Stat stat) {
            KeeperException.Code result = KeeperException.Code.get(rc);
            Assert.assertEquals(result, KeeperException.Code.OK);
            latch.countDown();
        }
    };
    Watcher existWatch = new Watcher() {

        @Override
        public void process(WatchedEvent event) {
            Assert.assertEquals(event.getType(), Event.EventType.NodeCreated);
            _zkClient.getZooKeeper().exists(event.getPath(), null, existCallback, null);
        }
    };
    AsyncCallback.StatCallback existCallback2 = new AsyncCallback.StatCallback() {

        @Override
        public void processResult(int rc, String path, Object ctx, Stat stat) {
            KeeperException.Code result = KeeperException.Code.get(rc);
            Assert.assertEquals(result, KeeperException.Code.NONODE);
            latch2.countDown();
        }
    };
    // symlink /$link doesn't exist.
    _zkClient.getZooKeeper().exists("/$link", existWatch, existCallback2, null);
    latch2.await(30, TimeUnit.SECONDS);
    // create symlink /$link -> /foo/bar. existWatch should be notified.
    _zkClient.createSymlink("/$link", "/foo/bar", new FutureCallback<None>());
    latch.await(30, TimeUnit.SECONDS);
    // delete symlink /$link
    _zkClient.removeNodeUnsafe("/$link", new FutureCallback<None>());
}

Example 52 with Watcher

use of org.apache.zookeeper.Watcher in project rest.li by linkedin.

the class SymlinkAwareZooKeeperTest method testSymlinkWithChildrenWatcher2.

@Test
public void testSymlinkWithChildrenWatcher2() throws ExecutionException, InterruptedException {
    final CountDownLatch latch1 = new CountDownLatch(1);
    final CountDownLatch latch2 = new CountDownLatch(1);
    final AsyncCallback.ChildrenCallback callback2 = new AsyncCallback.ChildrenCallback() {

        @Override
        public void processResult(int rc, String path, Object ctx, List<String> children) {
            Assert.assertEquals(path, "/foo/$link");
            Assert.assertEquals(children.size(), 5);
            latch2.countDown();
        }
    };
    Watcher watcher = new Watcher() {

        @Override
        public void process(WatchedEvent event) {
            Assert.assertEquals(event.getType(), Event.EventType.NodeChildrenChanged);
            _zkClient.getZooKeeper().getChildren(event.getPath(), null, callback2, null);
        }
    };
    AsyncCallback.ChildrenCallback callback = new AsyncCallback.ChildrenCallback() {

        @Override
        public void processResult(int rc, String path, Object ctx, List<String> children) {
            latch1.countDown();
        }
    };
    // set watcher to /foo/$link
    _zkClient.getZooKeeper().getChildren("/foo/$link", watcher, callback, null);
    latch1.await(30, TimeUnit.SECONDS);
    // update symlink
    _zkClient.setSymlinkData("/foo/$link", "/bar/foo", new FutureCallback<None>());
    latch2.await(30, TimeUnit.SECONDS);
    FutureCallback<None> fcb = new FutureCallback<None>();
    // restore symlink
    _zkClient.setSymlinkData("/foo/$link", "/foo/bar", fcb);
    fcb.get();
}

Example 53 with Watcher

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

the class ZKClientTest method testRetry.

@Test
public void testRetry() throws ExecutionException, InterruptedException, TimeoutException {
    File dataDir = Files.createTempDir();
    InMemoryZKServer zkServer = InMemoryZKServer.builder().setDataDir(dataDir).setTickTime(1000).build();
    zkServer.startAndWait();
    int port = zkServer.getLocalAddress().getPort();
    final CountDownLatch disconnectLatch = new CountDownLatch(1);
    ZKClientService client = ZKClientServices.delegate(ZKClients.retryOnFailure(ZKClientService.Builder.of(zkServer.getConnectionStr()).setConnectionWatcher(new Watcher() {

        @Override
        public void process(WatchedEvent event) {
            if (event.getState() == Event.KeeperState.Disconnected) {
                disconnectLatch.countDown();
            }
        }
    }).build(), RetryStrategies.fixDelay(0, TimeUnit.SECONDS)));
    client.startAndWait();
    zkServer.stopAndWait();
    Assert.assertTrue(disconnectLatch.await(1, TimeUnit.SECONDS));
    final CountDownLatch createLatch = new CountDownLatch(1);
    Futures.addCallback(client.create("/testretry/test", null, CreateMode.PERSISTENT), new FutureCallback<String>() {

        @Override
        public void onSuccess(String result) {
            createLatch.countDown();
        }

        @Override
        public void onFailure(Throwable t) {
            t.printStackTrace(System.out);
        }
    });
    TimeUnit.SECONDS.sleep(2);
    zkServer = InMemoryZKServer.builder().setDataDir(dataDir).setAutoCleanDataDir(true).setPort(port).setTickTime(1000).build();
    zkServer.startAndWait();
    try {
        Assert.assertTrue(createLatch.await(5, TimeUnit.SECONDS));
    } finally {
        zkServer.stopAndWait();
    }
}

Example 54 with Watcher

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

the class TestZKWatcherManager method testRegisterUnregisterWatcher.

@Test(timeout = 60000)
public void testRegisterUnregisterWatcher() throws Exception {
    ZKWatcherManager watcherManager = ZKWatcherManager.newBuilder().name("test-register-unregister-watcher").statsLogger(NullStatsLogger.INSTANCE).build();
    String path = "/test-register-unregister-watcher";
    final List<WatchedEvent> events = new LinkedList<WatchedEvent>();
    final CountDownLatch latch = new CountDownLatch(2);
    Watcher watcher = new Watcher() {

        @Override
        public void process(WatchedEvent event) {
            events.add(event);
            latch.countDown();
        }
    };
    watcherManager.registerChildWatcher(path, watcher);
    // fire the event
    WatchedEvent event0 = new WatchedEvent(Watcher.Event.EventType.NodeCreated, Watcher.Event.KeeperState.SyncConnected, path);
    WatchedEvent event1 = new WatchedEvent(Watcher.Event.EventType.None, Watcher.Event.KeeperState.SyncConnected, path);
    WatchedEvent event2 = new WatchedEvent(Watcher.Event.EventType.NodeChildrenChanged, Watcher.Event.KeeperState.SyncConnected, path);
    watcher.process(event1);
    watcher.process(event2);
    latch.await();
    assertEquals(2, events.size());
    assertEquals(event1, events.get(0));
    assertEquals(event2, events.get(1));
    // unregister watcher
    watcherManager.unregisterChildWatcher(path, watcher);
    assertEquals(0, watcherManager.childWatches.size());
}

Example 55 with Watcher

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

the class ZooKeeperClient method registerExpirationHandler.

/**
   * 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 Command onExpired) {
    Watcher watcher = new Watcher() {

        @Override
        public void process(WatchedEvent event) {
            if (event.getType() == EventType.None && event.getState() == KeeperState.Expired) {
                onExpired.execute();
            }
        }
    };
    register(watcher);
    return watcher;
}