Examples with IZkDataListener org.I0Itec.zkclient.IZkDataListener used on opensource projects

Example 11 with IZkDataListener

use of org.I0Itec.zkclient.IZkDataListener in project helix by apache.

the class TestHelper method printZkListeners.

public static void printZkListeners(ZkClient client) throws Exception {
    Map<String, Set<IZkDataListener>> datalisteners = ZkTestHelper.getZkDataListener(client);
    Map<String, Set<IZkChildListener>> childListeners = ZkTestHelper.getZkChildListener(client);
    System.out.println("dataListeners {");
    for (String path : datalisteners.keySet()) {
        System.out.println("\t" + path + ": ");
        Set<IZkDataListener> set = datalisteners.get(path);
        for (IZkDataListener listener : set) {
            CallbackHandler handler = (CallbackHandler) listener;
            System.out.println("\t\t" + handler.getListener());
        }
    }
    System.out.println("}");
    System.out.println("childListeners {");
    for (String path : childListeners.keySet()) {
        System.out.println("\t" + path + ": ");
        Set<IZkChildListener> set = childListeners.get(path);
        for (IZkChildListener listener : set) {
            CallbackHandler handler = (CallbackHandler) listener;
            System.out.println("\t\t" + handler.getListener());
        }
    }
    System.out.println("}");
}

Example 12 with IZkDataListener

use of org.I0Itec.zkclient.IZkDataListener in project helix by apache.

the class TestZkBasis method testWatchRemove.

/**
 * after calling zkclient#unsubscribeXXXListener()
 * an already registered watch will not be removed from ZooKeeper#watchManager#XXXWatches
 * immediately.
 * the watch will get removed on the following conditions:
 * 1) there is a set/delete on the listening path via the zkclient
 * 2) session expiry on the zkclient (i.e. the watch will not be renewed after session expiry)
 * @throws Exception
 */
@Test
public void testWatchRemove() throws Exception {
    String className = TestHelper.getTestClassName();
    String methodName = TestHelper.getTestMethodName();
    String testName = className + "_" + methodName;
    final ZkClient client = new ZkClient(ZK_ADDR, ZkClient.DEFAULT_SESSION_TIMEOUT, ZkClient.DEFAULT_CONNECTION_TIMEOUT, new ZNRecordSerializer());
    // make sure "/testName/test" doesn't exist
    final String path = "/" + testName + "/test";
    client.createPersistent(path, true);
    ZkListener listener = new ZkListener();
    client.subscribeDataChanges(path, listener);
    client.subscribeChildChanges(path, listener);
    // listener should be in both ZkClient#_dataListener and ZkClient#_childListener set
    Map<String, Set<IZkDataListener>> dataListenerMap = ZkTestHelper.getZkDataListener(client);
    Assert.assertEquals(dataListenerMap.size(), 1, "ZkClient#_dataListener should have 1 listener");
    Set<IZkDataListener> dataListenerSet = dataListenerMap.get(path);
    Assert.assertNotNull(dataListenerSet, "ZkClient#_dataListener should have 1 listener on path: " + path);
    Assert.assertEquals(dataListenerSet.size(), 1, "ZkClient#_dataListener should have 1 listener on path: " + path);
    Map<String, Set<IZkChildListener>> childListenerMap = ZkTestHelper.getZkChildListener(client);
    Assert.assertEquals(childListenerMap.size(), 1, "ZkClient#_childListener should have 1 listener");
    Set<IZkChildListener> childListenerSet = childListenerMap.get(path);
    Assert.assertNotNull(childListenerSet, "ZkClient#_childListener should have 1 listener on path: " + path);
    Assert.assertEquals(childListenerSet.size(), 1, "ZkClient#_childListener should have 1 listener on path: " + path);
    // watch should be in ZooKeeper#watchManager#XXXWatches
    Map<String, List<String>> watchMap = ZkTestHelper.getZkWatch(client);
    // System.out.println("watchMap1: " + watchMap);
    List<String> dataWatch = watchMap.get("dataWatches");
    Assert.assertNotNull(dataWatch, "ZooKeeper#watchManager#dataWatches should have 1 data watch on path: " + path);
    Assert.assertEquals(dataWatch.size(), 1, "ZooKeeper#watchManager#dataWatches should have 1 data watch on path: " + path);
    Assert.assertEquals(dataWatch.get(0), path, "ZooKeeper#watchManager#dataWatches should have 1 data watch on path: " + path);
    List<String> childWatch = watchMap.get("childWatches");
    Assert.assertNotNull(childWatch, "ZooKeeper#watchManager#childWatches should have 1 child watch on path: " + path);
    Assert.assertEquals(childWatch.size(), 1, "ZooKeeper#watchManager#childWatches should have 1 child watch on path: " + path);
    Assert.assertEquals(childWatch.get(0), path, "ZooKeeper#watchManager#childWatches should have 1 child watch on path: " + path);
    client.unsubscribeDataChanges(path, listener);
    client.unsubscribeChildChanges(path, listener);
    // System.out.println("watchMap2: " + watchMap);
    ZkTestHelper.expireSession(client);
    // after session expiry, those watches should be removed
    watchMap = ZkTestHelper.getZkWatch(client);
    // System.out.println("watchMap3: " + watchMap);
    dataWatch = watchMap.get("dataWatches");
    Assert.assertTrue(dataWatch.isEmpty(), "ZooKeeper#watchManager#dataWatches should be empty");
    childWatch = watchMap.get("childWatches");
    Assert.assertTrue(childWatch.isEmpty(), "ZooKeeper#watchManager#childWatches should be empty");
    client.close();
}

Example 13 with IZkDataListener

use of org.I0Itec.zkclient.IZkDataListener in project helix by apache.

the class TestZkCallbackHandlerLeak method printZkListeners.

void printZkListeners(ZkClient client) throws Exception {
    Map<String, Set<IZkDataListener>> datalisteners = ZkTestHelper.getZkDataListener(client);
    Map<String, Set<IZkChildListener>> childListeners = ZkTestHelper.getZkChildListener(client);
    System.out.println("dataListeners {");
    for (String path : datalisteners.keySet()) {
        System.out.println("\t" + path + ": ");
        Set<IZkDataListener> set = datalisteners.get(path);
        for (IZkDataListener listener : set) {
            CallbackHandler handler = (CallbackHandler) listener;
            System.out.println("\t\t" + handler.getListener());
        }
    }
    System.out.println("}");
    System.out.println("childListeners {");
    for (String path : childListeners.keySet()) {
        System.out.println("\t" + path + ": ");
        Set<IZkChildListener> set = childListeners.get(path);
        for (IZkChildListener listener : set) {
            CallbackHandler handler = (CallbackHandler) listener;
            System.out.println("\t\t" + handler.getListener());
        }
    }
    System.out.println("}");
}

Example 14 with IZkDataListener

use of org.I0Itec.zkclient.IZkDataListener in project helix by apache.

the class ZkClient method isPrefetchEnabled.

private boolean isPrefetchEnabled(IZkDataListener dataListener) {
    PreFetch preFetch = dataListener.getClass().getAnnotation(PreFetch.class);
    if (preFetch != null) {
        return preFetch.enabled();
    }
    Method callbackMethod = IZkDataListener.class.getMethods()[0];
    try {
        Method method = dataListener.getClass().getMethod(callbackMethod.getName(), callbackMethod.getParameterTypes());
        PreFetch preFetchInMethod = method.getAnnotation(PreFetch.class);
        if (preFetchInMethod != null) {
            return preFetchInMethod.enabled();
        }
    } catch (NoSuchMethodException e) {
        LOG.warn("No method " + callbackMethod.getName() + " defined in listener " + dataListener.getClass().getCanonicalName());
    }
    return true;
}

Example 15 with IZkDataListener

use of org.I0Itec.zkclient.IZkDataListener in project samza by apache.

the class TestZkLeaderElector method testLeaderFailure.

/**
 * Tests that Leader Failure automatically promotes the next successor to become the leader
 */
@Test
public void testLeaderFailure() {
    /**
     * electionLatch and count together verify that:
     * 1. the registered listeners are actually invoked by the ZkClient on the correct path
     * 2. for a single participant failure, at-most 1 other participant is notified
     */
    final CountDownLatch electionLatch = new CountDownLatch(1);
    final AtomicInteger count = new AtomicInteger(0);
    BooleanResult isLeader1 = new BooleanResult();
    BooleanResult isLeader2 = new BooleanResult();
    BooleanResult isLeader3 = new BooleanResult();
    // Processor-1
    ZkUtils zkUtils1 = getZkUtilsWithNewClient();
    zkUtils1.registerProcessorAndGetId(new ProcessorData("processor1", "1"));
    ZkLeaderElector leaderElector1 = new ZkLeaderElector("processor1", zkUtils1, new IZkDataListener() {

        @Override
        public void handleDataChange(String dataPath, Object data) throws Exception {
        }

        @Override
        public void handleDataDeleted(String dataPath) throws Exception {
            count.incrementAndGet();
        }
    });
    leaderElector1.setLeaderElectorListener(() -> isLeader1.res = true);
    // Processor-2
    ZkUtils zkUtils2 = getZkUtilsWithNewClient();
    final String path2 = zkUtils2.registerProcessorAndGetId(new ProcessorData("processor2", "2"));
    ZkLeaderElector leaderElector2 = new ZkLeaderElector("processor2", zkUtils2, new IZkDataListener() {

        @Override
        public void handleDataChange(String dataPath, Object data) throws Exception {
        }

        @Override
        public void handleDataDeleted(String dataPath) throws Exception {
            String registeredIdStr = ZkKeyBuilder.parseIdFromPath(path2);
            Assert.assertNotNull(registeredIdStr);
            String predecessorIdStr = ZkKeyBuilder.parseIdFromPath(dataPath);
            Assert.assertNotNull(predecessorIdStr);
            try {
                int selfId = Integer.parseInt(registeredIdStr);
                int predecessorId = Integer.parseInt(predecessorIdStr);
                Assert.assertEquals(1, selfId - predecessorId);
            } catch (Exception e) {
                LOG.error(e.getLocalizedMessage());
            }
            count.incrementAndGet();
            electionLatch.countDown();
        }
    });
    leaderElector2.setLeaderElectorListener(() -> isLeader2.res = true);
    // Processor-3
    ZkUtils zkUtils3 = getZkUtilsWithNewClient();
    zkUtils3.registerProcessorAndGetId(new ProcessorData("processor3", "3"));
    ZkLeaderElector leaderElector3 = new ZkLeaderElector("processor3", zkUtils3, new IZkDataListener() {

        @Override
        public void handleDataChange(String dataPath, Object data) throws Exception {
        }

        @Override
        public void handleDataDeleted(String dataPath) throws Exception {
            count.incrementAndGet();
        }
    });
    leaderElector3.setLeaderElectorListener(() -> isLeader3.res = true);
    // Join Leader Election
    leaderElector1.tryBecomeLeader();
    leaderElector2.tryBecomeLeader();
    leaderElector3.tryBecomeLeader();
    Assert.assertTrue(TestZkUtils.testWithDelayBackOff(() -> isLeader1.res, 2, 100));
    Assert.assertFalse(TestZkUtils.testWithDelayBackOff(() -> isLeader2.res, 2, 100));
    Assert.assertFalse(TestZkUtils.testWithDelayBackOff(() -> isLeader3.res, 2, 100));
    Assert.assertTrue(leaderElector1.amILeader());
    Assert.assertFalse(leaderElector2.amILeader());
    Assert.assertFalse(leaderElector3.amILeader());
    List<String> currentActiveProcessors = zkUtils1.getSortedActiveProcessorsZnodes();
    Assert.assertEquals(3, currentActiveProcessors.size());
    // Leader Failure
    zkUtils1.close();
    currentActiveProcessors.remove(0);
    try {
        Assert.assertTrue(electionLatch.await(5, TimeUnit.SECONDS));
    } catch (InterruptedException e) {
        Assert.fail("Interrupted while waiting for leaderElection listener callback to complete!");
    }
    Assert.assertEquals(1, count.get());
    Assert.assertEquals(currentActiveProcessors, zkUtils2.getSortedActiveProcessorsZnodes());
    // Clean up
    zkUtils2.close();
    zkUtils3.close();
}