Java Code Examples for org.apache.hadoop.hdfs.inotify.MissingEventsException

The following examples show how to use org.apache.hadoop.hdfs.inotify.MissingEventsException. These examples are extracted from open source projects. You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may check out the related API usage on the sidebar.
Example 1
Source Project: localization_nifi   Source File: GetHDFSEvents.java    License: Apache License 2.0 6 votes vote down vote up
private EventBatch getEventBatch(DFSInotifyEventInputStream eventStream, long duration, TimeUnit timeUnit, int retries) throws IOException, InterruptedException, MissingEventsException {
    // According to the inotify API we should retry a few times if poll throws an IOException.
    // Please see org.apache.hadoop.hdfs.DFSInotifyEventInputStream#poll for documentation.
    int i = 0;
    while (true) {
        try {
            i += 1;
            return eventStream.poll(duration, timeUnit);
        } catch (IOException e) {
            if (i > retries) {
                getLogger().debug("Failed to poll for event batch. Reached max retry times.", e);
                throw e;
            } else {
                getLogger().debug("Attempt {} failed to poll for event batch. Retrying.", new Object[]{i});
            }
        }
    }
}
 
Example 2
Source Project: hadoop   Source File: DFSInotifyEventInputStream.java    License: Apache License 2.0 6 votes vote down vote up
/**
 * Returns the next batch of events in the stream, waiting indefinitely if
 * a new batch  is not immediately available.
 *
 * @throws IOException see {@link DFSInotifyEventInputStream#poll()}
 * @throws MissingEventsException see
 * {@link DFSInotifyEventInputStream#poll()}
 * @throws InterruptedException if the calling thread is interrupted
 */
public EventBatch take() throws IOException, InterruptedException,
    MissingEventsException {
  TraceScope scope = Trace.startSpan("inotifyTake", traceSampler);
  EventBatch next = null;
  try {
    int nextWaitMin = INITIAL_WAIT_MS;
    while ((next = poll()) == null) {
      // sleep for a random period between nextWaitMin and nextWaitMin * 2
      // to avoid stampedes at the NN if there are multiple clients
      int sleepTime = nextWaitMin + rng.nextInt(nextWaitMin);
      LOG.debug("take(): poll() returned null, sleeping for {} ms", sleepTime);
      Thread.sleep(sleepTime);
      // the maximum sleep is 2 minutes
      nextWaitMin = Math.min(60000, nextWaitMin * 2);
    }
  } finally {
    scope.close();
  }

  return next;
}
 
Example 3
Source Project: big-c   Source File: DFSInotifyEventInputStream.java    License: Apache License 2.0 6 votes vote down vote up
/**
 * Returns the next batch of events in the stream, waiting indefinitely if
 * a new batch  is not immediately available.
 *
 * @throws IOException see {@link DFSInotifyEventInputStream#poll()}
 * @throws MissingEventsException see
 * {@link DFSInotifyEventInputStream#poll()}
 * @throws InterruptedException if the calling thread is interrupted
 */
public EventBatch take() throws IOException, InterruptedException,
    MissingEventsException {
  TraceScope scope = Trace.startSpan("inotifyTake", traceSampler);
  EventBatch next = null;
  try {
    int nextWaitMin = INITIAL_WAIT_MS;
    while ((next = poll()) == null) {
      // sleep for a random period between nextWaitMin and nextWaitMin * 2
      // to avoid stampedes at the NN if there are multiple clients
      int sleepTime = nextWaitMin + rng.nextInt(nextWaitMin);
      LOG.debug("take(): poll() returned null, sleeping for {} ms", sleepTime);
      Thread.sleep(sleepTime);
      // the maximum sleep is 2 minutes
      nextWaitMin = Math.min(60000, nextWaitMin * 2);
    }
  } finally {
    scope.close();
  }

  return next;
}
 
Example 4
Source Project: nifi   Source File: GetHDFSEvents.java    License: Apache License 2.0 6 votes vote down vote up
private EventBatch getEventBatch(DFSInotifyEventInputStream eventStream, long duration, TimeUnit timeUnit, int retries) throws IOException, InterruptedException, MissingEventsException {
    // According to the inotify API we should retry a few times if poll throws an IOException.
    // Please see org.apache.hadoop.hdfs.DFSInotifyEventInputStream#poll for documentation.
    int i = 0;
    while (true) {
        try {
            i += 1;
            return eventStream.poll(duration, timeUnit);
        } catch (IOException e) {
            if (i > retries) {
                getLogger().debug("Failed to poll for event batch. Reached max retry times.", e);
                throw e;
            } else {
                getLogger().debug("Attempt {} failed to poll for event batch. Retrying.", new Object[]{i});
            }
        }
    }
}
 
Example 5
Source Project: hadoop   Source File: DFSInotifyEventInputStream.java    License: Apache License 2.0 5 votes vote down vote up
/**
 * Returns the next event batch in the stream, waiting up to the specified
 * amount of time for a new batch. Returns null if one is not available at the
 * end of the specified amount of time. The time before the method returns may
 * exceed the specified amount of time by up to the time required for an RPC
 * to the NameNode.
 *
 * @param time number of units of the given TimeUnit to wait
 * @param tu the desired TimeUnit
 * @throws IOException see {@link DFSInotifyEventInputStream#poll()}
 * @throws MissingEventsException
 * see {@link DFSInotifyEventInputStream#poll()}
 * @throws InterruptedException if the calling thread is interrupted
 */
public EventBatch poll(long time, TimeUnit tu) throws IOException,
    InterruptedException, MissingEventsException {
  TraceScope scope = Trace.startSpan("inotifyPollWithTimeout", traceSampler);
  EventBatch next = null;
  try {
    long initialTime = Time.monotonicNow();
    long totalWait = TimeUnit.MILLISECONDS.convert(time, tu);
    long nextWait = INITIAL_WAIT_MS;
    while ((next = poll()) == null) {
      long timeLeft = totalWait - (Time.monotonicNow() - initialTime);
      if (timeLeft <= 0) {
        LOG.debug("timed poll(): timed out");
        break;
      } else if (timeLeft < nextWait * 2) {
        nextWait = timeLeft;
      } else {
        nextWait *= 2;
      }
      LOG.debug("timed poll(): poll() returned null, sleeping for {} ms",
          nextWait);
      Thread.sleep(nextWait);
    }
  } finally {
    scope.close();
  }
  return next;
}
 
Example 6
Source Project: hadoop   Source File: TestDFSInotifyEventInputStream.java    License: Apache License 2.0 5 votes vote down vote up
@Test(timeout = 120000)
public void testNNFailover() throws IOException, URISyntaxException,
    MissingEventsException {
  Configuration conf = new HdfsConfiguration();
  MiniQJMHACluster cluster = new MiniQJMHACluster.Builder(conf).build();

  try {
    cluster.getDfsCluster().waitActive();
    cluster.getDfsCluster().transitionToActive(0);
    DFSClient client = ((DistributedFileSystem) HATestUtil.configureFailoverFs
        (cluster.getDfsCluster(), conf)).dfs;
    DFSInotifyEventInputStream eis = client.getInotifyEventStream();
    for (int i = 0; i < 10; i++) {
      client.mkdirs("/dir" + i, null, false);
    }
    cluster.getDfsCluster().shutdownNameNode(0);
    cluster.getDfsCluster().transitionToActive(1);
    EventBatch batch = null;
    // we can read all of the edits logged by the old active from the new
    // active
    for (int i = 0; i < 10; i++) {
      batch = waitForNextEvents(eis);
      Assert.assertEquals(1, batch.getEvents().length);
      Assert.assertTrue(batch.getEvents()[0].getEventType() == Event.EventType.CREATE);
      Assert.assertTrue(((Event.CreateEvent) batch.getEvents()[0]).getPath().equals("/dir" +
          i));
    }
    Assert.assertTrue(eis.poll() == null);
  } finally {
    cluster.shutdown();
  }
}
 
Example 7
Source Project: hadoop   Source File: TestDFSInotifyEventInputStream.java    License: Apache License 2.0 5 votes vote down vote up
@Test(timeout = 120000)
public void testReadEventsWithTimeout() throws IOException,
    InterruptedException, MissingEventsException {
  Configuration conf = new HdfsConfiguration();
  MiniQJMHACluster cluster = new MiniQJMHACluster.Builder(conf).build();

  try {
    cluster.getDfsCluster().waitActive();
    cluster.getDfsCluster().transitionToActive(0);
    final DFSClient client = new DFSClient(cluster.getDfsCluster()
        .getNameNode(0).getNameNodeAddress(), conf);
    DFSInotifyEventInputStream eis = client.getInotifyEventStream();
    ScheduledExecutorService ex = Executors
        .newSingleThreadScheduledExecutor();
    ex.schedule(new Runnable() {
      @Override
      public void run() {
        try {
          client.mkdirs("/dir", null, false);
        } catch (IOException e) {
          // test will fail
          LOG.error("Unable to create /dir", e);
        }
      }
    }, 1, TimeUnit.SECONDS);
    // a very generous wait period -- the edit will definitely have been
    // processed by the time this is up
    EventBatch batch = eis.poll(5, TimeUnit.SECONDS);
    Assert.assertNotNull(batch);
    Assert.assertEquals(1, batch.getEvents().length);
    Assert.assertTrue(batch.getEvents()[0].getEventType() == Event.EventType.CREATE);
    Assert.assertEquals("/dir", ((Event.CreateEvent) batch.getEvents()[0]).getPath());
  } finally {
    cluster.shutdown();
  }
}
 
Example 8
Source Project: big-c   Source File: DFSInotifyEventInputStream.java    License: Apache License 2.0 5 votes vote down vote up
/**
 * Returns the next event batch in the stream, waiting up to the specified
 * amount of time for a new batch. Returns null if one is not available at the
 * end of the specified amount of time. The time before the method returns may
 * exceed the specified amount of time by up to the time required for an RPC
 * to the NameNode.
 *
 * @param time number of units of the given TimeUnit to wait
 * @param tu the desired TimeUnit
 * @throws IOException see {@link DFSInotifyEventInputStream#poll()}
 * @throws MissingEventsException
 * see {@link DFSInotifyEventInputStream#poll()}
 * @throws InterruptedException if the calling thread is interrupted
 */
public EventBatch poll(long time, TimeUnit tu) throws IOException,
    InterruptedException, MissingEventsException {
  TraceScope scope = Trace.startSpan("inotifyPollWithTimeout", traceSampler);
  EventBatch next = null;
  try {
    long initialTime = Time.monotonicNow();
    long totalWait = TimeUnit.MILLISECONDS.convert(time, tu);
    long nextWait = INITIAL_WAIT_MS;
    while ((next = poll()) == null) {
      long timeLeft = totalWait - (Time.monotonicNow() - initialTime);
      if (timeLeft <= 0) {
        LOG.debug("timed poll(): timed out");
        break;
      } else if (timeLeft < nextWait * 2) {
        nextWait = timeLeft;
      } else {
        nextWait *= 2;
      }
      LOG.debug("timed poll(): poll() returned null, sleeping for {} ms",
          nextWait);
      Thread.sleep(nextWait);
    }
  } finally {
    scope.close();
  }
  return next;
}
 
Example 9
Source Project: big-c   Source File: TestDFSInotifyEventInputStream.java    License: Apache License 2.0 5 votes vote down vote up
@Test(timeout = 120000)
public void testNNFailover() throws IOException, URISyntaxException,
    MissingEventsException {
  Configuration conf = new HdfsConfiguration();
  MiniQJMHACluster cluster = new MiniQJMHACluster.Builder(conf).build();

  try {
    cluster.getDfsCluster().waitActive();
    cluster.getDfsCluster().transitionToActive(0);
    DFSClient client = ((DistributedFileSystem) HATestUtil.configureFailoverFs
        (cluster.getDfsCluster(), conf)).dfs;
    DFSInotifyEventInputStream eis = client.getInotifyEventStream();
    for (int i = 0; i < 10; i++) {
      client.mkdirs("/dir" + i, null, false);
    }
    cluster.getDfsCluster().shutdownNameNode(0);
    cluster.getDfsCluster().transitionToActive(1);
    EventBatch batch = null;
    // we can read all of the edits logged by the old active from the new
    // active
    for (int i = 0; i < 10; i++) {
      batch = waitForNextEvents(eis);
      Assert.assertEquals(1, batch.getEvents().length);
      Assert.assertTrue(batch.getEvents()[0].getEventType() == Event.EventType.CREATE);
      Assert.assertTrue(((Event.CreateEvent) batch.getEvents()[0]).getPath().equals("/dir" +
          i));
    }
    Assert.assertTrue(eis.poll() == null);
  } finally {
    cluster.shutdown();
  }
}
 
Example 10
Source Project: big-c   Source File: TestDFSInotifyEventInputStream.java    License: Apache License 2.0 5 votes vote down vote up
@Test(timeout = 120000)
public void testReadEventsWithTimeout() throws IOException,
    InterruptedException, MissingEventsException {
  Configuration conf = new HdfsConfiguration();
  MiniQJMHACluster cluster = new MiniQJMHACluster.Builder(conf).build();

  try {
    cluster.getDfsCluster().waitActive();
    cluster.getDfsCluster().transitionToActive(0);
    final DFSClient client = new DFSClient(cluster.getDfsCluster()
        .getNameNode(0).getNameNodeAddress(), conf);
    DFSInotifyEventInputStream eis = client.getInotifyEventStream();
    ScheduledExecutorService ex = Executors
        .newSingleThreadScheduledExecutor();
    ex.schedule(new Runnable() {
      @Override
      public void run() {
        try {
          client.mkdirs("/dir", null, false);
        } catch (IOException e) {
          // test will fail
          LOG.error("Unable to create /dir", e);
        }
      }
    }, 1, TimeUnit.SECONDS);
    // a very generous wait period -- the edit will definitely have been
    // processed by the time this is up
    EventBatch batch = eis.poll(5, TimeUnit.SECONDS);
    Assert.assertNotNull(batch);
    Assert.assertEquals(1, batch.getEvents().length);
    Assert.assertTrue(batch.getEvents()[0].getEventType() == Event.EventType.CREATE);
    Assert.assertEquals("/dir", ((Event.CreateEvent) batch.getEvents()[0]).getPath());
  } finally {
    cluster.shutdown();
  }
}
 
Example 11
Source Project: hadoop   Source File: DFSInotifyEventInputStream.java    License: Apache License 2.0 4 votes vote down vote up
/**
 * Returns the next batch of events in the stream or null if no new
 * batches are currently available.
 *
 * @throws IOException because of network error or edit log
 * corruption. Also possible if JournalNodes are unresponsive in the
 * QJM setting (even one unresponsive JournalNode is enough in rare cases),
 * so catching this exception and retrying at least a few times is
 * recommended.
 * @throws MissingEventsException if we cannot return the next batch in the
 * stream because the data for the events (and possibly some subsequent
 * events) has been deleted (generally because this stream is a very large
 * number of transactions behind the current state of the NameNode). It is
 * safe to continue reading from the stream after this exception is thrown
 * The next available batch of events will be returned.
 */
public EventBatch poll() throws IOException, MissingEventsException {
  TraceScope scope =
      Trace.startSpan("inotifyPoll", traceSampler);
  try {
    // need to keep retrying until the NN sends us the latest committed txid
    if (lastReadTxid == -1) {
      LOG.debug("poll(): lastReadTxid is -1, reading current txid from NN");
      lastReadTxid = namenode.getCurrentEditLogTxid();
      return null;
    }
    if (!it.hasNext()) {
      EventBatchList el = namenode.getEditsFromTxid(lastReadTxid + 1);
      if (el.getLastTxid() != -1) {
        // we only want to set syncTxid when we were actually able to read some
        // edits on the NN -- otherwise it will seem like edits are being
        // generated faster than we can read them when the problem is really
        // that we are temporarily unable to read edits
        syncTxid = el.getSyncTxid();
        it = el.getBatches().iterator();
        long formerLastReadTxid = lastReadTxid;
        lastReadTxid = el.getLastTxid();
        if (el.getFirstTxid() != formerLastReadTxid + 1) {
          throw new MissingEventsException(formerLastReadTxid + 1,
              el.getFirstTxid());
        }
      } else {
        LOG.debug("poll(): read no edits from the NN when requesting edits " +
          "after txid {}", lastReadTxid);
        return null;
      }
    }

    if (it.hasNext()) { // can be empty if el.getLastTxid != -1 but none of the
      // newly seen edit log ops actually got converted to events
      return it.next();
    } else {
      return null;
    }
  } finally {
    scope.close();
  }
}
 
Example 12
Source Project: hadoop   Source File: TestDFSInotifyEventInputStream.java    License: Apache License 2.0 4 votes vote down vote up
private static EventBatch waitForNextEvents(DFSInotifyEventInputStream eis)
  throws IOException, MissingEventsException {
  EventBatch batch = null;
  while ((batch = eis.poll()) == null);
  return batch;
}
 
Example 13
Source Project: hadoop   Source File: TestDFSInotifyEventInputStream.java    License: Apache License 2.0 4 votes vote down vote up
@Test(timeout = 120000)
public void testTwoActiveNNs() throws IOException, MissingEventsException {
  Configuration conf = new HdfsConfiguration();
  MiniQJMHACluster cluster = new MiniQJMHACluster.Builder(conf).build();

  try {
    cluster.getDfsCluster().waitActive();
    cluster.getDfsCluster().transitionToActive(0);
    DFSClient client0 = new DFSClient(cluster.getDfsCluster().getNameNode(0)
        .getNameNodeAddress(), conf);
    DFSClient client1 = new DFSClient(cluster.getDfsCluster().getNameNode(1)
        .getNameNodeAddress(), conf);
    DFSInotifyEventInputStream eis = client0.getInotifyEventStream();
    for (int i = 0; i < 10; i++) {
      client0.mkdirs("/dir" + i, null, false);
    }

    cluster.getDfsCluster().transitionToActive(1);
    for (int i = 10; i < 20; i++) {
      client1.mkdirs("/dir" + i, null, false);
    }

    // make sure that the old active can't read any further than the edits
    // it logged itself (it has no idea whether the in-progress edits from
    // the other writer have actually been committed)
    EventBatch batch = null;
    for (int i = 0; i < 10; i++) {
      batch = waitForNextEvents(eis);
      Assert.assertEquals(1, batch.getEvents().length);
      Assert.assertTrue(batch.getEvents()[0].getEventType() == Event.EventType.CREATE);
      Assert.assertTrue(((Event.CreateEvent) batch.getEvents()[0]).getPath().equals("/dir" +
          i));
    }
    Assert.assertTrue(eis.poll() == null);
  } finally {
    try {
      cluster.shutdown();
    } catch (ExitUtil.ExitException e) {
      // expected because the old active will be unable to flush the
      // end-of-segment op since it is fenced
    }
  }
}
 
Example 14
Source Project: big-c   Source File: DFSInotifyEventInputStream.java    License: Apache License 2.0 4 votes vote down vote up
/**
 * Returns the next batch of events in the stream or null if no new
 * batches are currently available.
 *
 * @throws IOException because of network error or edit log
 * corruption. Also possible if JournalNodes are unresponsive in the
 * QJM setting (even one unresponsive JournalNode is enough in rare cases),
 * so catching this exception and retrying at least a few times is
 * recommended.
 * @throws MissingEventsException if we cannot return the next batch in the
 * stream because the data for the events (and possibly some subsequent
 * events) has been deleted (generally because this stream is a very large
 * number of transactions behind the current state of the NameNode). It is
 * safe to continue reading from the stream after this exception is thrown
 * The next available batch of events will be returned.
 */
public EventBatch poll() throws IOException, MissingEventsException {
  TraceScope scope =
      Trace.startSpan("inotifyPoll", traceSampler);
  try {
    // need to keep retrying until the NN sends us the latest committed txid
    if (lastReadTxid == -1) {
      LOG.debug("poll(): lastReadTxid is -1, reading current txid from NN");
      lastReadTxid = namenode.getCurrentEditLogTxid();
      return null;
    }
    if (!it.hasNext()) {
      EventBatchList el = namenode.getEditsFromTxid(lastReadTxid + 1);
      if (el.getLastTxid() != -1) {
        // we only want to set syncTxid when we were actually able to read some
        // edits on the NN -- otherwise it will seem like edits are being
        // generated faster than we can read them when the problem is really
        // that we are temporarily unable to read edits
        syncTxid = el.getSyncTxid();
        it = el.getBatches().iterator();
        long formerLastReadTxid = lastReadTxid;
        lastReadTxid = el.getLastTxid();
        if (el.getFirstTxid() != formerLastReadTxid + 1) {
          throw new MissingEventsException(formerLastReadTxid + 1,
              el.getFirstTxid());
        }
      } else {
        LOG.debug("poll(): read no edits from the NN when requesting edits " +
          "after txid {}", lastReadTxid);
        return null;
      }
    }

    if (it.hasNext()) { // can be empty if el.getLastTxid != -1 but none of the
      // newly seen edit log ops actually got converted to events
      return it.next();
    } else {
      return null;
    }
  } finally {
    scope.close();
  }
}
 
Example 15
Source Project: big-c   Source File: TestDFSInotifyEventInputStream.java    License: Apache License 2.0 4 votes vote down vote up
private static EventBatch waitForNextEvents(DFSInotifyEventInputStream eis)
  throws IOException, MissingEventsException {
  EventBatch batch = null;
  while ((batch = eis.poll()) == null);
  return batch;
}
 
Example 16
Source Project: big-c   Source File: TestDFSInotifyEventInputStream.java    License: Apache License 2.0 4 votes vote down vote up
@Test(timeout = 120000)
public void testTwoActiveNNs() throws IOException, MissingEventsException {
  Configuration conf = new HdfsConfiguration();
  MiniQJMHACluster cluster = new MiniQJMHACluster.Builder(conf).build();

  try {
    cluster.getDfsCluster().waitActive();
    cluster.getDfsCluster().transitionToActive(0);
    DFSClient client0 = new DFSClient(cluster.getDfsCluster().getNameNode(0)
        .getNameNodeAddress(), conf);
    DFSClient client1 = new DFSClient(cluster.getDfsCluster().getNameNode(1)
        .getNameNodeAddress(), conf);
    DFSInotifyEventInputStream eis = client0.getInotifyEventStream();
    for (int i = 0; i < 10; i++) {
      client0.mkdirs("/dir" + i, null, false);
    }

    cluster.getDfsCluster().transitionToActive(1);
    for (int i = 10; i < 20; i++) {
      client1.mkdirs("/dir" + i, null, false);
    }

    // make sure that the old active can't read any further than the edits
    // it logged itself (it has no idea whether the in-progress edits from
    // the other writer have actually been committed)
    EventBatch batch = null;
    for (int i = 0; i < 10; i++) {
      batch = waitForNextEvents(eis);
      Assert.assertEquals(1, batch.getEvents().length);
      Assert.assertTrue(batch.getEvents()[0].getEventType() == Event.EventType.CREATE);
      Assert.assertTrue(((Event.CreateEvent) batch.getEvents()[0]).getPath().equals("/dir" +
          i));
    }
    Assert.assertTrue(eis.poll() == null);
  } finally {
    try {
      cluster.shutdown();
    } catch (ExitUtil.ExitException e) {
      // expected because the old active will be unable to flush the
      // end-of-segment op since it is fenced
    }
  }
}