Java Code Examples for org.apache.curator.framework.CuratorFramework#blockUntilConnected()

/** Connect a curator client to a running ZooKepper server. */
public static void connect(CuratorFramework client) {
    switch(client.getState()) {
        case LATENT :
            client.start();
            try { client.blockUntilConnected(); }
            catch (InterruptedException ex) { throw new RuntimeException(ex); }
            return;
        case STARTED :
            //LOG.warn("CuratorFramework already started");
            return ;
        case STOPPED :
            throw new DeltaException("CuratorFramework closed");
        default :
            break;
    }
}
 

/**
 * Test that we are actually connected every time that we block until connection is established in a tight loop.
 */
@Test
public void testBlockUntilConnectedTightLoop() throws InterruptedException
{
    CuratorFramework client;
    for(int i = 0 ; i < 50 ; i++)
    {
        client = CuratorFrameworkFactory.newClient(server.getConnectString(), new RetryOneTime(100));
        try
        {
            client.start();
            client.blockUntilConnected();

            Assert.assertTrue(client.getZookeeperClient().isConnected(), "Not connected after blocking for connection #" + i);
        }
        finally
        {
            client.close();
        }
    }
}
 

@Test
public void assertPersistSequential() throws Exception {
    assertThat(zkRegCenter.persistSequential("/sequential/test_sequential", "test_value"), startsWith("/sequential/test_sequential"));
    assertThat(zkRegCenter.persistSequential("/sequential/test_sequential", "test_value"), startsWith("/sequential/test_sequential"));
    CuratorFramework client = CuratorFrameworkFactory.newClient(EmbedTestingServer.getConnectionString(), new RetryOneTime(2000));
    client.start();
    client.blockUntilConnected();
    List<String> actual = client.getChildren().forPath("/" + ZookeeperRegistryCenterModifyTest.class.getName() + "/sequential");
    assertThat(actual.size(), is(2));
    for (String each : actual) {
        assertThat(each, startsWith("test_sequential"));
        assertThat(zkRegCenter.get("/sequential/" + each), startsWith("test_value"));
    }
    zkRegCenter.remove("/sequential");
    assertFalse(zkRegCenter.isExisted("/sequential"));
}
 

@Test
@Ignore
public void assertContend() throws Exception {
    CuratorFramework client = CuratorFrameworkFactory.newClient(EmbedTestingServer.getConnectionString(), new RetryOneTime(2000));
    client.start();
    client.blockUntilConnected();
    ZookeeperElectionService service = new ZookeeperElectionService(HOST_AND_PORT, client, ELECTION_PATH, electionCandidate);
    service.start();
    ElectionCandidate anotherElectionCandidate = mock(ElectionCandidate.class);
    CuratorFramework anotherClient = CuratorFrameworkFactory.newClient(EmbedTestingServer.getConnectionString(), new RetryOneTime(2000));
    ZookeeperElectionService anotherService = new ZookeeperElectionService("ANOTHER_CLIENT:8899", anotherClient, ELECTION_PATH, anotherElectionCandidate);
    anotherClient.start();
    anotherClient.blockUntilConnected();
    anotherService.start();
    KillSession.kill(client.getZookeeperClient().getZooKeeper(), EmbedTestingServer.getConnectionString());
    service.stop();
    verify(anotherElectionCandidate).startLeadership();
}
 

private static CuratorFramework createConnection() {
    String url = ZkConfig.getInstance().getZkURL();

    CuratorFramework curatorFramework = CuratorFrameworkFactory.newClient(url, new ExponentialBackoffRetry(100, 6));

    // start connection
    curatorFramework.start();
    // wait 3 second to establish connect
    try {
        curatorFramework.blockUntilConnected(3, TimeUnit.SECONDS);
        if (curatorFramework.getZookeeperClient().isConnected()) {
            return curatorFramework;
        }
    } catch (InterruptedException ignored) {
        Thread.currentThread().interrupt();
    }

    // fail situation
    curatorFramework.close();
    throw new RuntimeException("failed to connect to zookeeper service : " + url);
}
 

@Override
public CuratorFramework create(String address) throws InterruptedException {

	Builder builder = CuratorFrameworkFactory.builder();
	builder.connectionTimeoutMs(getZkConnectionTimeoutMillis());
	builder.connectString(address);
	builder.maxCloseWaitMs(getZkCloseWaitMillis());
	builder.namespace(getZkNamespace());
	builder.retryPolicy(new RetryNTimes(getZkRetries(), getSleepMsBetweenRetries()));
	builder.sessionTimeoutMs(getZkSessionTimeoutMillis());
	builder.threadFactory(XpipeThreadFactory.create("Xpipe-ZK-" + address, true));

	logger.info("[create]{}, {}", Codec.DEFAULT.encode(this), address);
	CuratorFramework curatorFramework = builder.build();
	curatorFramework.start();
	curatorFramework.blockUntilConnected(waitForZkConnectedMillis(), TimeUnit.MILLISECONDS);
	
	return curatorFramework;
}
 

private static CuratorFramework createConnection() {
    String url = ZkConfig.getInstance().getZkURL();
    CuratorFramework framework = CuratorFrameworkFactory.newClient(url, new ExponentialBackoffRetry(100, 6));
    // start connection
    framework.start();
    // wait 3 second to establish connect
    try {
        framework.blockUntilConnected(3, TimeUnit.SECONDS);
        if (framework.getZookeeperClient().isConnected()) {
            LOGGER.info("CuratorFramework createConnection success");
            return framework;
        }
    } catch (InterruptedException ignored) {
        LOGGER.info("CuratorFramework createConnection error", ignored);
        Thread.currentThread().interrupt();
    }
    // fail situation
    framework.close();
    throw new RuntimeException("failed to connect to zookeeper service : " + url);
}
 

private static CuratorFramework provideInitializedZookeeperClient(String zkConnection) throws Exception {

        LOG.info("Creating Zookeeper Client connecting to {}", zkConnection);

        RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000, 3);
        CuratorFramework zkClient = CuratorFrameworkFactory
                .builder()
                .namespace(NAMESPACE)
                .connectString(zkConnection)
                .retryPolicy(retryPolicy).build();

        LOG.info("Connecting to ZK cluster {}", zkClient.getState());
        zkClient.start();
        zkClient.blockUntilConnected();
        LOG.info("Connection to ZK cluster {}", zkClient.getState());

        return zkClient;
    }
 

/**
 * Spawns a new new background thread that will block until a connection is available and
 * then execute the 'runAfterConnection' logic
 *
 * @param client             The curator client
 * @param runAfterConnection The logic to run
 * @return future of the task so it can be canceled, etc. if needed
 */
public static Future<?> execute(final CuratorFramework client, final Runnable runAfterConnection) throws Exception
{
    //Block until connected
    final ExecutorService executor = ThreadUtils.newSingleThreadExecutor(ThreadUtils.getProcessName(runAfterConnection.getClass()));
    Runnable internalCall = new Runnable()
    {
        @Override
        public void run()
        {
            try
            {
                client.blockUntilConnected();
                runAfterConnection.run();
            }
            catch ( Exception e )
            {
                ThreadUtils.checkInterrupted(e);
                log.error("An error occurred blocking until a connection is available", e);
            }
            finally
            {
                executor.shutdown();
            }
        }
    };
    return executor.submit(internalCall);
}
 

@Test
public void testDisconnectEventOnWatcherDoesNotRetry() throws Exception
{
    final CountDownLatch gotSuspendEvent = new CountDownLatch(1);

    CuratorFramework curatorFramework = CuratorFrameworkFactory.newClient(server.getConnectString(), new RetryNTimes(10, 1000));
    curatorFramework.start();
    curatorFramework.blockUntilConnected();

    SharedCount sharedCount = new SharedCount(curatorFramework, "/count", 10);
    sharedCount.start();

    curatorFramework.getConnectionStateListenable().addListener(new ConnectionStateListener() {
        @Override
        public void stateChanged(CuratorFramework client, ConnectionState newState) {
            if (newState == ConnectionState.SUSPENDED) {
                gotSuspendEvent.countDown();
            }
        }
    });

    try
    {
        server.stop();
        // if watcher goes into 10second retry loop we won't get timely notification
        Assert.assertTrue(gotSuspendEvent.await(5, TimeUnit.SECONDS));
    }
    finally
    {
        CloseableUtils.closeQuietly(sharedCount);
        CloseableUtils.closeQuietly(curatorFramework);
    }
}
 

@Override
protected Result check() throws Exception {
	String mesosMaster = cfg.getMesosMaster();
	int zkIndex = mesosMaster.indexOf("zk://", 0);
	if (zkIndex >= 0) {
		String zkHostPorts = mesosMaster.substring(5,
				mesosMaster.indexOf("/", 5));

		String[] hostPorts = zkHostPorts.split(",");

		for (String hostPort : hostPorts) {
			CuratorFramework client = CuratorFrameworkFactory.newClient(
					hostPort, new ExponentialBackoffRetry(1000, 3));
			client.start();
			client.blockUntilConnected(5, TimeUnit.SECONDS);

			switch (client.getState()) {
			case STARTED:
				return Result.healthy();
			case STOPPED:
				LOGGER.fine("Unable to reach: " + hostPort);
			case LATENT:
				LOGGER.fine("Unable to reach: " + hostPort);
			default:
				LOGGER.fine("Unable to reach: " + hostPort);
			}
		}
	} else {
		if (HealthCheckUtils.checkHostPort(mesosMaster)) {
			return Result.healthy();
		}
	}

	return Result.unhealthy("Unable to connect to: " + mesosMaster);
}
 

@Bean(destroyMethod = "close")
@ConditionalOnMissingBean
public CuratorFramework curatorFramework(RetryPolicy retryPolicy,
		ZookeeperProperties properties,
		ObjectProvider<CuratorFrameworkCustomizer> optionalCuratorFrameworkCustomizerProvider,
		ObjectProvider<EnsembleProvider> optionalEnsembleProvider,
		ObjectProvider<TracerDriver> optionalTracerDriverProvider) throws Exception {
	CuratorFrameworkFactory.Builder builder = CuratorFrameworkFactory.builder();

	EnsembleProvider ensembleProvider = optionalEnsembleProvider.getIfAvailable();
	if (ensembleProvider != null) {
		builder.ensembleProvider(ensembleProvider);
	}
	else {
		builder.connectString(properties.getConnectString());
	}
	builder.sessionTimeoutMs((int) properties.getSessionTimeout().toMillis())
			.connectionTimeoutMs((int) properties.getConnectionTimeout().toMillis())
			.retryPolicy(retryPolicy);

	optionalCuratorFrameworkCustomizerProvider.orderedStream()
			.forEach(curatorFrameworkCustomizer -> curatorFrameworkCustomizer
					.customize(builder));

	CuratorFramework curator = builder.build();
	optionalTracerDriverProvider.ifAvailable(tracerDriver -> {
		if (curator.getZookeeperClient() != null) {
			curator.getZookeeperClient().setTracerDriver(tracerDriver);
		}
	});

	curator.start();
	log.trace("blocking until connected to zookeeper for "
			+ properties.getBlockUntilConnectedWait()
			+ properties.getBlockUntilConnectedUnit());
	curator.blockUntilConnected(properties.getBlockUntilConnectedWait(),
			properties.getBlockUntilConnectedUnit());
	log.trace("connected to zookeeper");
	return curator;
}
 

@Test
public void assertInitWithDigestSuccess() throws Exception {
    CuratorFramework client = CuratorFrameworkFactory.builder()
        .connectString(EmbedTestingServer.getConnectionString())
        .retryPolicy(new RetryOneTime(2000))
        .authorization("digest", "digest:password".getBytes()).build();
    client.start();
    client.blockUntilConnected();
    assertThat(client.getData().forPath("/" + ZookeeperRegistryCenterForAuthTest.class.getName() + "/test/deep/nested"), is("deepNested".getBytes()));
}
 

@Test(expected = NoAuthException.class)
public void assertInitWithDigestFailure() throws Exception {
    CuratorFramework client = CuratorFrameworkFactory.newClient(EmbedTestingServer.getConnectionString(), new RetryOneTime(2000));
    client.start();
    client.blockUntilConnected();
    client.getData().forPath("/" + ZookeeperRegistryCenterForAuthTest.class.getName() + "/test/deep/nested");
}
 

@Test
public void assertPersistEphemeral() throws Exception {
    zkRegCenter.persist("/persist", "persist_value");
    zkRegCenter.persistEphemeral("/ephemeral", "ephemeral_value");
    assertThat(zkRegCenter.get("/persist"), is("persist_value"));
    assertThat(zkRegCenter.get("/ephemeral"), is("ephemeral_value"));
    zkRegCenter.close();
    CuratorFramework client = CuratorFrameworkFactory.newClient(EmbedTestingServer.getConnectionString(), new RetryOneTime(2000));
    client.start();
    client.blockUntilConnected();
    assertThat(client.getData().forPath("/" + ZookeeperRegistryCenterModifyTest.class.getName() + "/persist"), is("persist_value".getBytes()));
    assertNull(client.checkExists().forPath("/" + ZookeeperRegistryCenterModifyTest.class.getName() + "/ephemeral"));
    zkRegCenter.init();
}
 

@Test(expected = NoAuthException.class)
public void assertInitWithDigestFailure() throws Exception {
    CuratorFramework client = CuratorFrameworkFactory.newClient(EmbedTestingServer.getConnectionString(), new RetryOneTime(2000));
    client.start();
    client.blockUntilConnected();
    client.getData().forPath("/" + ZookeeperRegistryCenterForAuthTest.class.getName() + "/test/deep/nested");
}
 

public static CuratorFramework provideConnectedZKClient(String zkCluster) throws Exception {

        LOG.info("Creating Zookeeper Client connecting to {}", zkCluster);

        RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000, 3);
        CuratorFramework zkClient = CuratorFrameworkFactory.builder().namespace("omid")
                .connectString(zkCluster).retryPolicy(retryPolicy).build();

        LOG.info("Connecting to ZK cluster {}", zkClient.getState());
        zkClient.start();
        zkClient.blockUntilConnected();
        LOG.info("Connection to ZK cluster {}", zkClient.getState());

        return zkClient;
    }
 

@Test
public void testReconnection() throws Exception {
  Record record = new Record().setName("my-service").setStatus(Status.UP);
  assertThat(record.getRegistration()).isNull();

  // Insertion
  AtomicReference<Record> reference = new AtomicReference<>();
  backend.store(record, ar -> {
    if (!ar.succeeded()) {
      ar.cause().printStackTrace();
    }
    reference.set(ar.result());
  });

  await().until(() -> reference.get() != null);
  assertThat(reference.get().getName()).isEqualToIgnoringCase("my-service");
  assertThat(reference.get().getRegistration()).isNotNull();
  record = reference.get();

  // Retrieve
  reference.set(null);
  backend.getRecord(record.getRegistration(), ar -> reference.set(ar.result()));
  await().until(() -> reference.get() != null);
  assertThat(reference.get().getName()).isEqualToIgnoringCase("my-service");
  assertThat(reference.get().getRegistration()).isNotNull();

  server.stop();

  AtomicReference<Throwable> error = new AtomicReference<>();
  backend.getRecord(record.getRegistration(), ar -> error.set(ar.cause()));
  await().until(() -> error.get() != null);
  assertThat(error.get()).isInstanceOf(KeeperException.ConnectionLossException.class);

  server.restart();
  CuratorFramework client = CuratorFrameworkFactory.builder()
      .connectString(server.getConnectString())
      .retryPolicy(new ExponentialBackoffRetry(10, 3))
      .build();
  client.start();
  // Wait until we have been connected to the server
  client.blockUntilConnected();

  reference.set(null);
  backend.getRecord(record.getRegistration(), ar -> {
    if (ar.failed()) {
      ar.cause().printStackTrace();
    }
    reference.set(ar.result());
  });


  await().until(() -> reference.get() != null);
  assertThat(reference.get().getName()).isEqualToIgnoringCase("my-service");
  assertThat(reference.get().getRegistration()).isNotNull();

  server.stop();

  // Remove
  AtomicBoolean completed = new AtomicBoolean();
  completed.set(false);
  backend.remove(record, ar -> completed.set(ar.failed()));
  await().untilAtomic(completed, is(true));

  server.restart();

  completed.set(false);
  backend.remove(record, ar -> completed.set(ar.succeeded()));
  await().untilAtomic(completed, is(true));

  client.close();
}
 

@ConditionalOnExpression("#{'${keymaster.address}' "
        + "matches '^((\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})|[a-z\\.]+):[0-9]+$'}")
@Bean
public CuratorFramework curatorFramework() throws InterruptedException {
    if (StringUtils.isNotBlank(username) && StringUtils.isNotBlank(password)) {
        javax.security.auth.login.Configuration.setConfiguration(new javax.security.auth.login.Configuration() {

            private final AppConfigurationEntry[] entries = {
                new AppConfigurationEntry(
                DigestLoginModule.class.getName(),
                AppConfigurationEntry.LoginModuleControlFlag.REQUIRED,
                Map.of(
                "username", username,
                "password", password
                ))
            };

            @Override
            public AppConfigurationEntry[] getAppConfigurationEntry(final String name) {
                return entries;
            }
        });
    }

    CuratorFrameworkFactory.Builder clientBuilder = CuratorFrameworkFactory.builder().
            connectString(address).
            retryPolicy(new ExponentialBackoffRetry(baseSleepTimeMs, maxRetries));
    if (StringUtils.isNotBlank(username)) {
        clientBuilder.authorization("digest", username.getBytes()).aclProvider(new ACLProvider() {

            @Override
            public List<ACL> getDefaultAcl() {
                return ZooDefs.Ids.CREATOR_ALL_ACL;
            }

            @Override
            public List<ACL> getAclForPath(final String path) {
                return ZooDefs.Ids.CREATOR_ALL_ACL;
            }
        });
    }
    CuratorFramework client = clientBuilder.build();
    client.start();
    client.blockUntilConnected(3, TimeUnit.SECONDS);

    return client;
}
 

/**
 * Test the case where we are not currently connected and the thread gets interrupted
 * prior to a connection becoming available
 */
@Test
public void testBlockUntilConnectedInterrupt()
{
    //Kill the server
    CloseableUtils.closeQuietly(server);

    final CuratorFramework client = CuratorFrameworkFactory.builder().
        connectString(server.getConnectString()).
        retryPolicy(new RetryOneTime(1)).
        build();

    try
    {
        client.start();

        final Thread threadToInterrupt = Thread.currentThread();

        Timer timer = new Timer();
        timer.schedule(new TimerTask()
        {

            @Override
            public void run()
            {
                threadToInterrupt.interrupt();
            }
        }, 3000);

        client.blockUntilConnected(5, TimeUnit.SECONDS);
        Assert.fail("Expected interruption did not occur");
    }
    catch ( InterruptedException e )
    {
        //This is expected
    }
    finally
    {
        CloseableUtils.closeQuietly(client);
    }
}