Java Discoverable类代码示例

import org.apache.twill.discovery.Discoverable; //导入依赖的package包/类
private Set<Integer> getInstances(Iterable<Discoverable> discoverables) throws IOException {
  Set<Integer> instances = Sets.newHashSet();
  for (Discoverable discoverable : discoverables) {
    InetSocketAddress socketAddress = discoverable.getSocketAddress();
    try (Socket socket = new Socket(socketAddress.getAddress(), socketAddress.getPort())) {
      PrintWriter writer = new PrintWriter(new OutputStreamWriter(socket.getOutputStream(), Charsets.UTF_8), true);
      LineReader reader = new LineReader(new InputStreamReader(socket.getInputStream(), Charsets.UTF_8));

      String msg = "Failure";
      writer.println(msg);

      String line = reader.readLine();
      Assert.assertTrue(line.endsWith(msg));
      instances.add(Integer.parseInt(line.substring(0, line.length() - msg.length())));
    }
  }
  return instances;
}
 

import org.apache.twill.discovery.Discoverable; //导入依赖的package包/类
private Set<Integer> getInstances(Iterable<Discoverable> discoverables) throws IOException {
  Set<Integer> instances = Sets.newHashSet();
  for (Discoverable discoverable : discoverables) {
    InetSocketAddress socketAddress = discoverable.getSocketAddress();
    Socket socket = new Socket(socketAddress.getAddress(), socketAddress.getPort());
    try {
      PrintWriter writer = new PrintWriter(new OutputStreamWriter(socket.getOutputStream(), Charsets.UTF_8), true);
      LineReader reader = new LineReader(new InputStreamReader(socket.getInputStream(), Charsets.UTF_8));

      String msg = "Failure";
      writer.println(msg);

      String line = reader.readLine();
      Assert.assertTrue(line.endsWith(msg));
      instances.add(Integer.parseInt(line.substring(0, line.length() - msg.length())));
    } finally {
      socket.close();
    }
  }
  return instances;
}
 

import org.apache.twill.discovery.Discoverable; //导入依赖的package包/类
@Test
public void testEnv() throws Exception {
  TwillRunner runner = getTwillRunner();

  TwillController controller = runner.prepare(new EchoApp())
    .addLogHandler(new PrinterLogHandler(new PrintWriter(System.out, true)))
    .withApplicationArguments("echo")
    .withArguments("echo1", "echo1")
    .withArguments("echo2", "echo2")
    .withEnv(ImmutableMap.of("GREETING", "Hello"))
    .withEnv("echo2", ImmutableMap.of("GREETING", "Hello2"))
    .start();

  // Service echo1 should returns "Hello" as greeting, echo2 should returns "Hello2"
  Map<String, String> runnableGreetings = ImmutableMap.of("echo1", "Hello", "echo2", "Hello2");
  for (Map.Entry<String, String> entry : runnableGreetings.entrySet()) {
    Discoverable discoverable = getDiscoverable(controller.discoverService(entry.getKey()), 60, TimeUnit.SECONDS);
    try (
      Socket socket = new Socket(discoverable.getSocketAddress().getAddress(),
                                 discoverable.getSocketAddress().getPort())
    ) {
      PrintWriter writer = new PrintWriter(new OutputStreamWriter(socket.getOutputStream(), Charsets.UTF_8), true);
      LineReader reader = new LineReader(new InputStreamReader(socket.getInputStream(), Charsets.UTF_8));

      writer.println("GREETING");
      Assert.assertEquals(entry.getValue(), reader.readLine());
    }
  }

  controller.terminate().get();
}
 

import org.apache.twill.discovery.Discoverable; //导入依赖的package包/类
@Test
public void testFailureRestart() throws Exception {
  TwillRunner runner = getTwillRunner();

  ResourceSpecification resource = ResourceSpecification.Builder.with()
    .setVirtualCores(1)
    .setMemory(512, ResourceSpecification.SizeUnit.MEGA)
    .setInstances(2)
    .build();
  TwillController controller = runner.prepare(new FailureRunnable(), resource)
    .withApplicationArguments("failure")
    .withArguments(FailureRunnable.class.getSimpleName(), "failure2")
    .addLogHandler(new PrinterLogHandler(new PrintWriter(System.out, true)))
    .start();

  Iterable<Discoverable> discoverables = controller.discoverService("failure");
  Assert.assertTrue(waitForSize(discoverables, 2, 120));

  // Make sure we see the right instance IDs
  Assert.assertEquals(Sets.newHashSet(0, 1), getInstances(discoverables));

  // Kill server with instanceId = 0
  controller.sendCommand(FailureRunnable.class.getSimpleName(), Command.Builder.of("kill0").build());

  // Make sure the runnable is killed.
  Assert.assertTrue(waitForSize(discoverables, 1, 120));

  // Wait for the restart
  Assert.assertTrue(waitForSize(discoverables, 2, 120));

  // Make sure we see the right instance IDs
  Assert.assertEquals(Sets.newHashSet(0, 1), getInstances(discoverables));

  controller.terminate().get(120, TimeUnit.SECONDS);
}
 

import org.apache.twill.discovery.Discoverable; //导入依赖的package包/类
@Provides
@Singleton
private DiscoveryService providesDiscoveryService(final ZKClientService zkClient,
                                                  final ZKDiscoveryService delegate) {
  return new DiscoveryService() {
    @Override
    public Cancellable register(Discoverable discoverable) {
      if (!zkClient.isRunning()) {
        zkClient.startAndWait();
      }
      return delegate.register(discoverable);
    }
  };
}
 

import org.apache.twill.discovery.Discoverable; //导入依赖的package包/类
@Override
public Discoverable pick() {
  // Reservoir sampling
  Discoverable result = null;
  Iterator<Discoverable> itor = endpoints.iterator();
  Random random = new Random();
  int count = 0;
  while (itor.hasNext()) {
    Discoverable next = itor.next();
    if (random.nextInt(++count) == 0) {
      result = next;
    }
  }
  return result;
}
 

import org.apache.twill.discovery.Discoverable; //导入依赖的package包/类
@Test
public void testLocalFile() throws Exception {
  String header = Files.readFirstLine(new File(getClass().getClassLoader().getResource("header.txt").toURI()),
                                      Charsets.UTF_8);

  TwillRunner runner = YarnTestUtils.getTwillRunner();

  TwillController controller = runner.prepare(new LocalFileApplication())
    .addJVMOptions(" -verbose:gc -Xloggc:gc.log -XX:+PrintGCDetails")
    .withApplicationArguments("local")
    .withArguments("LocalFileSocketServer", "local2")
    .addLogHandler(new PrinterLogHandler(new PrintWriter(System.out, true)))
    .start();

  Iterable<Discoverable> discoverables = controller.discoverService("local");
  Assert.assertTrue(YarnTestUtils.waitForSize(discoverables, 1, 60));

  InetSocketAddress socketAddress = discoverables.iterator().next().getSocketAddress();
  Socket socket = new Socket(socketAddress.getAddress(), socketAddress.getPort());
  try {
    PrintWriter writer = new PrintWriter(new OutputStreamWriter(socket.getOutputStream(), Charsets.UTF_8), true);
    LineReader reader = new LineReader(new InputStreamReader(socket.getInputStream(), Charsets.UTF_8));

    String msg = "Local file test";
    writer.println(msg);
    Assert.assertEquals(header, reader.readLine());
    Assert.assertEquals(msg, reader.readLine());
  } finally {
    socket.close();
  }

  controller.stopAndWait();

  Assert.assertTrue(YarnTestUtils.waitForSize(discoverables, 0, 60));

  TimeUnit.SECONDS.sleep(2);
}
 

import org.apache.twill.discovery.Discoverable; //导入依赖的package包/类
@Test
public void testFailureRestart() throws Exception {
  TwillRunner runner = YarnTestUtils.getTwillRunner();

  ResourceSpecification resource = ResourceSpecification.Builder.with()
    .setVirtualCores(1)
    .setMemory(512, ResourceSpecification.SizeUnit.MEGA)
    .setInstances(2)
    .build();
  TwillController controller = runner.prepare(new FailureRunnable(), resource)
    .withApplicationArguments("failure")
    .withArguments(FailureRunnable.class.getSimpleName(), "failure2")
    .addLogHandler(new PrinterLogHandler(new PrintWriter(System.out, true)))
    .start();

  Iterable<Discoverable> discoverables = controller.discoverService("failure");
  Assert.assertTrue(YarnTestUtils.waitForSize(discoverables, 2, 120));

  // Make sure we see the right instance IDs
  Assert.assertEquals(Sets.newHashSet(0, 1), getInstances(discoverables));

  // Kill server with instanceId = 0
  controller.sendCommand(FailureRunnable.class.getSimpleName(), Command.Builder.of("kill0").build());

  // Make sure the runnable is killed.
  Assert.assertTrue(YarnTestUtils.waitForSize(discoverables, 1, 120));

  // Wait for the restart
  Assert.assertTrue(YarnTestUtils.waitForSize(discoverables, 2, 120));

  // Make sure we see the right instance IDs
  Assert.assertEquals(Sets.newHashSet(0, 1), getInstances(discoverables));

  controller.stopAndWait();
}
 

import org.apache.twill.discovery.Discoverable; //导入依赖的package包/类
@Override
public Cancellable announce(final String serviceName, final int port) {
  return discoveryService.register(new Discoverable() {
    @Override
    public String getName() {
      return serviceName;
    }

    @Override
    public InetSocketAddress getSocketAddress() {
      return new InetSocketAddress(getHost(), port);
    }
  });
}
 

import org.apache.twill.discovery.Discoverable; //导入依赖的package包/类
@Test
public void testZKCleanup() throws Exception {
  final ZKClientService zkClient = ZKClientService.Builder.of(getZKConnectionString() + "/twill").build();
  zkClient.startAndWait();

  try {
    TwillRunner runner = getTwillRunner();

    // Start an application and stop it.
    TwillController controller = runner.prepare(new EchoServer())
      .addLogHandler(new PrinterLogHandler(new PrintWriter(System.out, true)))
      .withApplicationArguments("echo")
      .withArguments("EchoServer", "echo2")
      .start();

    Iterable<Discoverable> echoServices = controller.discoverService("echo");
    Assert.assertTrue(waitForSize(echoServices, 1, 120));

    controller.terminate().get();

    // Verify the ZK node gets cleanup
    waitFor(null, new Callable<Stat>() {
      @Override
      public Stat call() throws Exception {
        return zkClient.exists("/EchoServer").get();
      }
    }, 10000, 100, TimeUnit.MILLISECONDS);

    // Start two instances of the application and stop one of it
    List<TwillController> controllers = new ArrayList<>();
    for (int i = 0; i < 2; i++) {
      controllers.add(runner.prepare(new EchoServer())
                        .addLogHandler(new PrinterLogHandler(new PrintWriter(System.out, true)))
                        .withApplicationArguments("echo")
                        .withArguments("EchoServer", "echo2")
                        .start());
    }

    // There should be two instances up and running.
    echoServices = controllers.get(1).discoverService("echo");
    Assert.assertTrue(waitForSize(echoServices, 2, 120));

    // Stop one instance of the app
    controllers.get(0).terminate().get();

    // Verify the ZK node should still be there
    Assert.assertNotNull(zkClient.exists("/EchoServer").get());

    // We should still be able to do discovery, which depends on the ZK node.
    echoServices = controllers.get(1).discoverService("echo");
    Assert.assertTrue(waitForSize(echoServices, 1, 120));

    // Stop second instance of the app
    controllers.get(1).terminate().get();

    // Verify the ZK node gets cleanup
    waitFor(null, new Callable<Stat>() {
      @Override
      public Stat call() throws Exception {
        return zkClient.exists("/EchoServer").get();
      }
    }, 10000, 100, TimeUnit.MILLISECONDS);

  } finally {
    zkClient.stopAndWait();
  }
}
 

import org.apache.twill.discovery.Discoverable; //导入依赖的package包/类
@Test
public void testRunnablesGetAllowedResourcesInEnv() throws InterruptedException, IOException,
  TimeoutException, ExecutionException {
  TwillRunner runner = getTwillRunner();

  ResourceSpecification resourceSpec = ResourceSpecification.Builder.with()
    .setVirtualCores(1)
    .setMemory(2048, ResourceSpecification.SizeUnit.MEGA)
    .setInstances(1)
    .build();
  TwillController controller = runner.prepare(new EnvironmentEchoServer(), resourceSpec)
    .addLogHandler(new PrinterLogHandler(new PrintWriter(System.out, true)))
    .withApplicationArguments("envecho")
    .withArguments("EnvironmentEchoServer", "echo2")
    .start();

  final CountDownLatch running = new CountDownLatch(1);
  controller.onRunning(new Runnable() {
    @Override
    public void run() {
      running.countDown();
    }
  }, Threads.SAME_THREAD_EXECUTOR);

  Assert.assertTrue(running.await(120, TimeUnit.SECONDS));

  Iterable<Discoverable> envEchoServices = controller.discoverService("envecho");
  Assert.assertTrue(waitForSize(envEchoServices, 1, 120));

  // TODO: check virtual cores once yarn adds the ability
  Map<String, String> expectedValues = Maps.newHashMap();
  expectedValues.put(EnvKeys.YARN_CONTAINER_MEMORY_MB, "2048");
  expectedValues.put(EnvKeys.TWILL_INSTANCE_COUNT, "1");

  // check environment of the runnable.
  Discoverable discoverable = envEchoServices.iterator().next();
  for (Map.Entry<String, String> expected : expectedValues.entrySet()) {
    try (
      Socket socket = new Socket(discoverable.getSocketAddress().getHostName(),
                                 discoverable.getSocketAddress().getPort())
    ) {
      PrintWriter writer = new PrintWriter(new OutputStreamWriter(socket.getOutputStream(), Charsets.UTF_8), true);
      LineReader reader = new LineReader(new InputStreamReader(socket.getInputStream(), Charsets.UTF_8));
      writer.println(expected.getKey());
      Assert.assertEquals(expected.getValue(), reader.readLine());
    }
  }

  controller.terminate().get(120, TimeUnit.SECONDS);
  // Sleep a bit before exiting.
  TimeUnit.SECONDS.sleep(2);
}
 

import org.apache.twill.discovery.Discoverable; //导入依赖的package包/类
@Test
public void testResourceReportWithFailingContainers() throws InterruptedException, IOException,
  TimeoutException, ExecutionException {
  TwillRunner runner = getTwillRunner();

  ResourceSpecification resourceSpec = ResourceSpecification.Builder.with()
    .setVirtualCores(1)
    .setMemory(256, ResourceSpecification.SizeUnit.MEGA)
    .setInstances(2)
    .build();
  TwillController controller = runner.prepare(new BuggyServer(), resourceSpec)
    .addLogHandler(new PrinterLogHandler(new PrintWriter(System.out, true)))
    .withApplicationArguments("echo")
    .withArguments("BuggyServer", "echo2")
    .start();

  final CountDownLatch running = new CountDownLatch(1);
  controller.onRunning(new Runnable() {
    @Override
    public void run() {
      running.countDown();
    }
  }, Threads.SAME_THREAD_EXECUTOR);

  Assert.assertTrue(running.await(120, TimeUnit.SECONDS));

  Iterable<Discoverable> echoServices = controller.discoverService("echo");
  Assert.assertTrue(waitForSize(echoServices, 2, 120));
  // check that we have 2 runnables.
  ResourceReport report = getResourceReport(controller, 10000);
  Assert.assertEquals(2, report.getRunnableResources("BuggyServer").size());

  // cause a divide by 0 in one server
  Discoverable discoverable = echoServices.iterator().next();
  try (
    Socket socket = new Socket(discoverable.getSocketAddress().getAddress(),
                               discoverable.getSocketAddress().getPort())
  ) {
    PrintWriter writer = new PrintWriter(new OutputStreamWriter(socket.getOutputStream(), Charsets.UTF_8), true);
    writer.println("0");
  }

  // takes some time for app master to find out the container completed...
  int count = 0;
  while (count < 100) {
    report = getResourceReport(controller, 10000);
    // check that we have 1 runnable, not 2.
    if (report.getRunnableResources("BuggyServer").size() == 1) {
      break;
    }
    LOG.info("Wait for BuggyServer to have 1 instance left. Trial {}.", count);
    count++;
    TimeUnit.SECONDS.sleep(1);
  }
  Assert.assertTrue("Still has 2 contains running after 100 seconds", count < 100);

  controller.terminate().get(100, TimeUnit.SECONDS);
  // Sleep a bit before exiting.
  TimeUnit.SECONDS.sleep(2);
}
 

import org.apache.twill.discovery.Discoverable; //导入依赖的package包/类
@Test
public void testLocalFile() throws Exception {
  // Generate a header and a footer files.
  File headerFile = tmpFolder.newFile("header.txt");
  File footerFile = tmpFolder.newFile("footer.txt");

  String headerMsg = "Header Message";
  String footerMsg = "Footer Message";

  Files.write(headerMsg, headerFile, StandardCharsets.UTF_8);
  Files.write(footerMsg, footerFile, StandardCharsets.UTF_8);

  TwillRunner runner = getTwillRunner();

  TwillController controller = runner.prepare(new LocalFileApplication(headerFile))
    .addJVMOptions(" -verbose:gc -Xloggc:gc.log -XX:+PrintGCDetails")
    .withApplicationArguments("local")
    .withArguments("LocalFileSocketServer", "local2")
    .withResources(footerFile.toURI())
    .addLogHandler(new PrinterLogHandler(new PrintWriter(System.out, true)))
    .start();

  Iterable<Discoverable> discoverables = controller.discoverService("local");
  Assert.assertTrue(waitForSize(discoverables, 1, 60));

  InetSocketAddress socketAddress = discoverables.iterator().next().getSocketAddress();
  try (Socket socket = new Socket(socketAddress.getAddress(), socketAddress.getPort())) {
    PrintWriter writer = new PrintWriter(new OutputStreamWriter(socket.getOutputStream(), Charsets.UTF_8), true);
    LineReader reader = new LineReader(new InputStreamReader(socket.getInputStream(), Charsets.UTF_8));

    String msg = "Local file test";
    writer.println(msg);
    Assert.assertEquals(headerMsg, reader.readLine());
    Assert.assertEquals(msg, reader.readLine());
    Assert.assertEquals(footerMsg, reader.readLine());
  }

  controller.terminate().get(120, TimeUnit.SECONDS);

  Assert.assertTrue(waitForSize(discoverables, 0, 60));

  TimeUnit.SECONDS.sleep(2);
}
 

import org.apache.twill.discovery.Discoverable; //导入依赖的package包/类
@Override
public Cancellable announce(final String serviceName, final int port, final byte[] payload) {
  return discoveryService.register(new Discoverable(serviceName, new InetSocketAddress(getHost(), port), payload));
}
 

import org.apache.twill.discovery.Discoverable; //导入依赖的package包/类
protected void doRegister() {
  cancelDiscovery = discoveryService.register(new Discoverable(serviceName, getAddress()));
}