Java Code Examples for org.apache.hadoop.fs.HdfsBlockLocation

The following examples show how to use org.apache.hadoop.fs.HdfsBlockLocation. 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: hadoop   Source File: TestCombineFileInputFormat.java    License: Apache License 2.0 6 votes vote down vote up
@Override
public BlockLocation[] getFileBlockLocations(
    FileStatus stat, long start, long len) throws IOException {
  if (stat.isDir()) {
    return null;
  }
  System.out.println("File " + stat.getPath());
  String name = stat.getPath().toUri().getPath();
  BlockLocation[] locs =
    super.getFileBlockLocations(stat, start, len);
  if (name.equals(fileWithMissingBlocks)) {
    System.out.println("Returning missing blocks for " + fileWithMissingBlocks);
    locs[0] = new HdfsBlockLocation(new BlockLocation(new String[0],
        new String[0], locs[0].getOffset(), locs[0].getLength()), null);
  }
  return locs;
}
 
Example 2
Source Project: hadoop   Source File: DFSClient.java    License: Apache License 2.0 6 votes vote down vote up
/**
 * Get block location info about file
 * 
 * getBlockLocations() returns a list of hostnames that store 
 * data for a specific file region.  It returns a set of hostnames
 * for every block within the indicated region.
 *
 * This function is very useful when writing code that considers
 * data-placement when performing operations.  For example, the
 * MapReduce system tries to schedule tasks on the same machines
 * as the data-block the task processes. 
 */
public BlockLocation[] getBlockLocations(String src, long start, 
      long length) throws IOException, UnresolvedLinkException {
  TraceScope scope = getPathTraceScope("getBlockLocations", src);
  try {
    LocatedBlocks blocks = getLocatedBlocks(src, start, length);
    BlockLocation[] locations =  DFSUtil.locatedBlocks2Locations(blocks);
    HdfsBlockLocation[] hdfsLocations = new HdfsBlockLocation[locations.length];
    for (int i = 0; i < locations.length; i++) {
      hdfsLocations[i] = new HdfsBlockLocation(locations[i], blocks.get(i));
    }
    return hdfsLocations;
  } finally {
    scope.close();
  }
}
 
Example 3
Source Project: hadoop   Source File: TestFsDatasetCache.java    License: Apache License 2.0 6 votes vote down vote up
@Test(timeout=60000)
public void testUncacheUnknownBlock() throws Exception {
  // Create a file
  Path fileName = new Path("/testUncacheUnknownBlock");
  int fileLen = 4096;
  DFSTestUtil.createFile(fs, fileName, fileLen, (short)1, 0xFDFD);
  HdfsBlockLocation[] locs = (HdfsBlockLocation[])fs.getFileBlockLocations(
      fileName, 0, fileLen);

  // Try to uncache it without caching it first
  setHeartbeatResponse(uncacheBlocks(locs));

  GenericTestUtils.waitFor(new Supplier<Boolean>() {
    @Override
    public Boolean get() {
      return fsd.getNumBlocksFailedToUncache() > 0;
    }
  }, 100, 10000);
}
 
Example 4
Source Project: hadoop   Source File: TestFsDatasetCache.java    License: Apache License 2.0 6 votes vote down vote up
@Test(timeout=60000)
public void testPageRounder() throws Exception {
  // Write a small file
  Path fileName = new Path("/testPageRounder");
  final int smallBlocks = 512; // This should be smaller than the page size
  assertTrue("Page size should be greater than smallBlocks!",
      PAGE_SIZE > smallBlocks);
  final int numBlocks = 5;
  final int fileLen = smallBlocks * numBlocks;
  FSDataOutputStream out =
      fs.create(fileName, false, 4096, (short)1, smallBlocks);
  out.write(new byte[fileLen]);
  out.close();
  HdfsBlockLocation[] locs = (HdfsBlockLocation[])fs.getFileBlockLocations(
      fileName, 0, fileLen);
  // Cache the file and check the sizes match the page size
  setHeartbeatResponse(cacheBlocks(locs));
  DFSTestUtil.verifyExpectedCacheUsage(PAGE_SIZE * numBlocks, numBlocks, fsd);
  // Uncache and check that it decrements by the page size too
  setHeartbeatResponse(uncacheBlocks(locs));
  DFSTestUtil.verifyExpectedCacheUsage(0, 0, fsd);
}
 
Example 5
Source Project: big-c   Source File: TestCombineFileInputFormat.java    License: Apache License 2.0 6 votes vote down vote up
@Override
public BlockLocation[] getFileBlockLocations(
    FileStatus stat, long start, long len) throws IOException {
  if (stat.isDir()) {
    return null;
  }
  System.out.println("File " + stat.getPath());
  String name = stat.getPath().toUri().getPath();
  BlockLocation[] locs =
    super.getFileBlockLocations(stat, start, len);
  if (name.equals(fileWithMissingBlocks)) {
    System.out.println("Returning missing blocks for " + fileWithMissingBlocks);
    locs[0] = new HdfsBlockLocation(new BlockLocation(new String[0],
        new String[0], locs[0].getOffset(), locs[0].getLength()), null);
  }
  return locs;
}
 
Example 6
Source Project: big-c   Source File: DFSClient.java    License: Apache License 2.0 6 votes vote down vote up
/**
 * Get block location info about file
 * 
 * getBlockLocations() returns a list of hostnames that store 
 * data for a specific file region.  It returns a set of hostnames
 * for every block within the indicated region.
 *
 * This function is very useful when writing code that considers
 * data-placement when performing operations.  For example, the
 * MapReduce system tries to schedule tasks on the same machines
 * as the data-block the task processes. 
 */
public BlockLocation[] getBlockLocations(String src, long start, 
      long length) throws IOException, UnresolvedLinkException {
  TraceScope scope = getPathTraceScope("getBlockLocations", src);
  try {
    LocatedBlocks blocks = getLocatedBlocks(src, start, length);
    BlockLocation[] locations =  DFSUtil.locatedBlocks2Locations(blocks);
    HdfsBlockLocation[] hdfsLocations = new HdfsBlockLocation[locations.length];
    for (int i = 0; i < locations.length; i++) {
      hdfsLocations[i] = new HdfsBlockLocation(locations[i], blocks.get(i));
    }
    return hdfsLocations;
  } finally {
    scope.close();
  }
}
 
Example 7
Source Project: big-c   Source File: TestFsDatasetCache.java    License: Apache License 2.0 6 votes vote down vote up
@Test(timeout=60000)
public void testUncacheUnknownBlock() throws Exception {
  // Create a file
  Path fileName = new Path("/testUncacheUnknownBlock");
  int fileLen = 4096;
  DFSTestUtil.createFile(fs, fileName, fileLen, (short)1, 0xFDFD);
  HdfsBlockLocation[] locs = (HdfsBlockLocation[])fs.getFileBlockLocations(
      fileName, 0, fileLen);

  // Try to uncache it without caching it first
  setHeartbeatResponse(uncacheBlocks(locs));

  GenericTestUtils.waitFor(new Supplier<Boolean>() {
    @Override
    public Boolean get() {
      return fsd.getNumBlocksFailedToUncache() > 0;
    }
  }, 100, 10000);
}
 
Example 8
Source Project: big-c   Source File: TestFsDatasetCache.java    License: Apache License 2.0 6 votes vote down vote up
@Test(timeout=60000)
public void testPageRounder() throws Exception {
  // Write a small file
  Path fileName = new Path("/testPageRounder");
  final int smallBlocks = 512; // This should be smaller than the page size
  assertTrue("Page size should be greater than smallBlocks!",
      PAGE_SIZE > smallBlocks);
  final int numBlocks = 5;
  final int fileLen = smallBlocks * numBlocks;
  FSDataOutputStream out =
      fs.create(fileName, false, 4096, (short)1, smallBlocks);
  out.write(new byte[fileLen]);
  out.close();
  HdfsBlockLocation[] locs = (HdfsBlockLocation[])fs.getFileBlockLocations(
      fileName, 0, fileLen);
  // Cache the file and check the sizes match the page size
  setHeartbeatResponse(cacheBlocks(locs));
  DFSTestUtil.verifyExpectedCacheUsage(PAGE_SIZE * numBlocks, numBlocks, fsd);
  // Uncache and check that it decrements by the page size too
  setHeartbeatResponse(uncacheBlocks(locs));
  DFSTestUtil.verifyExpectedCacheUsage(0, 0, fsd);
}
 
Example 9
Source Project: hadoop   Source File: TestFsDatasetCache.java    License: Apache License 2.0 5 votes vote down vote up
/**
 * Creates a cache or uncache DatanodeCommand from an array of locations
 */
private static DatanodeCommand getResponse(HdfsBlockLocation[] locs,
    int action) {
  String bpid = locs[0].getLocatedBlock().getBlock().getBlockPoolId();
  long[] blocks = new long[locs.length];
  for (int i=0; i<locs.length; i++) {
    blocks[i] = locs[i].getLocatedBlock().getBlock().getBlockId();
  }
  return new BlockIdCommand(action, bpid, blocks);
}
 
Example 10
Source Project: big-c   Source File: TestFsDatasetCache.java    License: Apache License 2.0 5 votes vote down vote up
/**
 * Creates a cache or uncache DatanodeCommand from an array of locations
 */
private static DatanodeCommand getResponse(HdfsBlockLocation[] locs,
    int action) {
  String bpid = locs[0].getLocatedBlock().getBlock().getBlockPoolId();
  long[] blocks = new long[locs.length];
  for (int i=0; i<locs.length; i++) {
    blocks[i] = locs[i].getLocatedBlock().getBlock().getBlockId();
  }
  return new BlockIdCommand(action, bpid, blocks);
}
 
Example 11
private static String getFirstBlockId(FileSystem fileSystem, Path realFile) throws IOException {
  FileStatus fileStatus = fileSystem.getFileStatus(realFile);
  BlockLocation[] locations = fileSystem.getFileBlockLocations(fileStatus, 0, 1);
  HdfsBlockLocation location = (HdfsBlockLocation) locations[0];
  LocatedBlock locatedBlock = location.getLocatedBlock();
  ExtendedBlock block = locatedBlock.getBlock();
  return toNiceString(block.getBlockId());
}
 
Example 12
Source Project: hadoop   Source File: DFSClient.java    License: Apache License 2.0 4 votes vote down vote up
/**
 * Get block location information about a list of {@link HdfsBlockLocation}.
 * Used by {@link DistributedFileSystem#getFileBlockStorageLocations(List)} to
 * get {@link BlockStorageLocation}s for blocks returned by
 * {@link DistributedFileSystem#getFileBlockLocations(org.apache.hadoop.fs.FileStatus, long, long)}
 * .
 * 
 * This is done by making a round of RPCs to the associated datanodes, asking
 * the volume of each block replica. The returned array of
 * {@link BlockStorageLocation} expose this information as a
 * {@link VolumeId}.
 * 
 * @param blockLocations
 *          target blocks on which to query volume location information
 * @return volumeBlockLocations original block array augmented with additional
 *         volume location information for each replica.
 */
public BlockStorageLocation[] getBlockStorageLocations(
    List<BlockLocation> blockLocations) throws IOException,
    UnsupportedOperationException, InvalidBlockTokenException {
  if (!getConf().getHdfsBlocksMetadataEnabled) {
    throw new UnsupportedOperationException("Datanode-side support for " +
        "getVolumeBlockLocations() must also be enabled in the client " +
        "configuration.");
  }
  // Downcast blockLocations and fetch out required LocatedBlock(s)
  List<LocatedBlock> blocks = new ArrayList<LocatedBlock>();
  for (BlockLocation loc : blockLocations) {
    if (!(loc instanceof HdfsBlockLocation)) {
      throw new ClassCastException("DFSClient#getVolumeBlockLocations " +
          "expected to be passed HdfsBlockLocations");
    }
    HdfsBlockLocation hdfsLoc = (HdfsBlockLocation) loc;
    blocks.add(hdfsLoc.getLocatedBlock());
  }
  
  // Re-group the LocatedBlocks to be grouped by datanodes, with the values
  // a list of the LocatedBlocks on the datanode.
  Map<DatanodeInfo, List<LocatedBlock>> datanodeBlocks = 
      new LinkedHashMap<DatanodeInfo, List<LocatedBlock>>();
  for (LocatedBlock b : blocks) {
    for (DatanodeInfo info : b.getLocations()) {
      if (!datanodeBlocks.containsKey(info)) {
        datanodeBlocks.put(info, new ArrayList<LocatedBlock>());
      }
      List<LocatedBlock> l = datanodeBlocks.get(info);
      l.add(b);
    }
  }
      
  // Make RPCs to the datanodes to get volume locations for its replicas
  TraceScope scope =
    Trace.startSpan("getBlockStorageLocations", traceSampler);
  Map<DatanodeInfo, HdfsBlocksMetadata> metadatas;
  try {
    metadatas = BlockStorageLocationUtil.
        queryDatanodesForHdfsBlocksMetadata(conf, datanodeBlocks,
            getConf().getFileBlockStorageLocationsNumThreads,
            getConf().getFileBlockStorageLocationsTimeoutMs,
            getConf().connectToDnViaHostname);
    if (LOG.isTraceEnabled()) {
      LOG.trace("metadata returned: "
          + Joiner.on("\n").withKeyValueSeparator("=").join(metadatas));
    }
  } finally {
    scope.close();
  }
  
  // Regroup the returned VolumeId metadata to again be grouped by
  // LocatedBlock rather than by datanode
  Map<LocatedBlock, List<VolumeId>> blockVolumeIds = BlockStorageLocationUtil
      .associateVolumeIdsWithBlocks(blocks, metadatas);
  
  // Combine original BlockLocations with new VolumeId information
  BlockStorageLocation[] volumeBlockLocations = BlockStorageLocationUtil
      .convertToVolumeBlockLocations(blocks, blockVolumeIds);

  return volumeBlockLocations;
}
 
Example 13
Source Project: hadoop   Source File: TestFsDatasetCache.java    License: Apache License 2.0 4 votes vote down vote up
private static DatanodeCommand[] cacheBlock(HdfsBlockLocation loc) {
  return cacheBlocks(new HdfsBlockLocation[] {loc});
}
 
Example 14
Source Project: hadoop   Source File: TestFsDatasetCache.java    License: Apache License 2.0 4 votes vote down vote up
private static DatanodeCommand[] cacheBlocks(HdfsBlockLocation[] locs) {
  return new DatanodeCommand[] {
      getResponse(locs, DatanodeProtocol.DNA_CACHE)
  };
}
 
Example 15
Source Project: hadoop   Source File: TestFsDatasetCache.java    License: Apache License 2.0 4 votes vote down vote up
private static DatanodeCommand[] uncacheBlock(HdfsBlockLocation loc) {
  return uncacheBlocks(new HdfsBlockLocation[] {loc});
}
 
Example 16
Source Project: hadoop   Source File: TestFsDatasetCache.java    License: Apache License 2.0 4 votes vote down vote up
private static DatanodeCommand[] uncacheBlocks(HdfsBlockLocation[] locs) {
  return new DatanodeCommand[] {
      getResponse(locs, DatanodeProtocol.DNA_UNCACHE)
  };
}
 
Example 17
Source Project: hadoop   Source File: TestFsDatasetCache.java    License: Apache License 2.0 4 votes vote down vote up
@Test(timeout=600000)
public void testFilesExceedMaxLockedMemory() throws Exception {
  LOG.info("beginning testFilesExceedMaxLockedMemory");

  // Create some test files that will exceed total cache capacity
  final int numFiles = 5;
  final long fileSize = CACHE_CAPACITY / (numFiles-1);

  final Path[] testFiles = new Path[numFiles];
  final HdfsBlockLocation[][] fileLocs = new HdfsBlockLocation[numFiles][];
  final long[] fileSizes = new long[numFiles];
  for (int i=0; i<numFiles; i++) {
    testFiles[i] = new Path("/testFilesExceedMaxLockedMemory-" + i);
    DFSTestUtil.createFile(fs, testFiles[i], fileSize, (short)1, 0xDFAl);
    fileLocs[i] = (HdfsBlockLocation[])fs.getFileBlockLocations(
        testFiles[i], 0, fileSize);
    // Get the file size (sum of blocks)
    long[] sizes = getBlockSizes(fileLocs[i]);
    for (int j=0; j<sizes.length; j++) {
      fileSizes[i] += sizes[j];
    }
  }

  // Cache the first n-1 files
  long total = 0;
  DFSTestUtil.verifyExpectedCacheUsage(0, 0, fsd);
  for (int i=0; i<numFiles-1; i++) {
    setHeartbeatResponse(cacheBlocks(fileLocs[i]));
    total = DFSTestUtil.verifyExpectedCacheUsage(
        rounder.round(total + fileSizes[i]), 4 * (i + 1), fsd);
  }

  // nth file should hit a capacity exception
  final LogVerificationAppender appender = new LogVerificationAppender();
  final Logger logger = Logger.getRootLogger();
  logger.addAppender(appender);
  setHeartbeatResponse(cacheBlocks(fileLocs[numFiles-1]));

  GenericTestUtils.waitFor(new Supplier<Boolean>() {
    @Override
    public Boolean get() {
      int lines = appender.countLinesWithMessage(
          "more bytes in the cache: " +
          DFSConfigKeys.DFS_DATANODE_MAX_LOCKED_MEMORY_KEY);
      return lines > 0;
    }
  }, 500, 30000);
  // Also check the metrics for the failure
  assertTrue("Expected more than 0 failed cache attempts",
      fsd.getNumBlocksFailedToCache() > 0);

  // Uncache the n-1 files
  int curCachedBlocks = 16;
  for (int i=0; i<numFiles-1; i++) {
    setHeartbeatResponse(uncacheBlocks(fileLocs[i]));
    long uncachedBytes = rounder.round(fileSizes[i]);
    total -= uncachedBytes;
    curCachedBlocks -= uncachedBytes / BLOCK_SIZE;
    DFSTestUtil.verifyExpectedCacheUsage(total, curCachedBlocks, fsd);
  }
  LOG.info("finishing testFilesExceedMaxLockedMemory");
}
 
Example 18
Source Project: big-c   Source File: DFSClient.java    License: Apache License 2.0 4 votes vote down vote up
/**
 * Get block location information about a list of {@link HdfsBlockLocation}.
 * Used by {@link DistributedFileSystem#getFileBlockStorageLocations(List)} to
 * get {@link BlockStorageLocation}s for blocks returned by
 * {@link DistributedFileSystem#getFileBlockLocations(org.apache.hadoop.fs.FileStatus, long, long)}
 * .
 * 
 * This is done by making a round of RPCs to the associated datanodes, asking
 * the volume of each block replica. The returned array of
 * {@link BlockStorageLocation} expose this information as a
 * {@link VolumeId}.
 * 
 * @param blockLocations
 *          target blocks on which to query volume location information
 * @return volumeBlockLocations original block array augmented with additional
 *         volume location information for each replica.
 */
public BlockStorageLocation[] getBlockStorageLocations(
    List<BlockLocation> blockLocations) throws IOException,
    UnsupportedOperationException, InvalidBlockTokenException {
  if (!getConf().getHdfsBlocksMetadataEnabled) {
    throw new UnsupportedOperationException("Datanode-side support for " +
        "getVolumeBlockLocations() must also be enabled in the client " +
        "configuration.");
  }
  // Downcast blockLocations and fetch out required LocatedBlock(s)
  List<LocatedBlock> blocks = new ArrayList<LocatedBlock>();
  for (BlockLocation loc : blockLocations) {
    if (!(loc instanceof HdfsBlockLocation)) {
      throw new ClassCastException("DFSClient#getVolumeBlockLocations " +
          "expected to be passed HdfsBlockLocations");
    }
    HdfsBlockLocation hdfsLoc = (HdfsBlockLocation) loc;
    blocks.add(hdfsLoc.getLocatedBlock());
  }
  
  // Re-group the LocatedBlocks to be grouped by datanodes, with the values
  // a list of the LocatedBlocks on the datanode.
  Map<DatanodeInfo, List<LocatedBlock>> datanodeBlocks = 
      new LinkedHashMap<DatanodeInfo, List<LocatedBlock>>();
  for (LocatedBlock b : blocks) {
    for (DatanodeInfo info : b.getLocations()) {
      if (!datanodeBlocks.containsKey(info)) {
        datanodeBlocks.put(info, new ArrayList<LocatedBlock>());
      }
      List<LocatedBlock> l = datanodeBlocks.get(info);
      l.add(b);
    }
  }
      
  // Make RPCs to the datanodes to get volume locations for its replicas
  TraceScope scope =
    Trace.startSpan("getBlockStorageLocations", traceSampler);
  Map<DatanodeInfo, HdfsBlocksMetadata> metadatas;
  try {
    metadatas = BlockStorageLocationUtil.
        queryDatanodesForHdfsBlocksMetadata(conf, datanodeBlocks,
            getConf().getFileBlockStorageLocationsNumThreads,
            getConf().getFileBlockStorageLocationsTimeoutMs,
            getConf().connectToDnViaHostname);
    if (LOG.isTraceEnabled()) {
      LOG.trace("metadata returned: "
          + Joiner.on("\n").withKeyValueSeparator("=").join(metadatas));
    }
  } finally {
    scope.close();
  }
  
  // Regroup the returned VolumeId metadata to again be grouped by
  // LocatedBlock rather than by datanode
  Map<LocatedBlock, List<VolumeId>> blockVolumeIds = BlockStorageLocationUtil
      .associateVolumeIdsWithBlocks(blocks, metadatas);
  
  // Combine original BlockLocations with new VolumeId information
  BlockStorageLocation[] volumeBlockLocations = BlockStorageLocationUtil
      .convertToVolumeBlockLocations(blocks, blockVolumeIds);

  return volumeBlockLocations;
}
 
Example 19
Source Project: big-c   Source File: TestFsDatasetCache.java    License: Apache License 2.0 4 votes vote down vote up
private static DatanodeCommand[] cacheBlock(HdfsBlockLocation loc) {
  return cacheBlocks(new HdfsBlockLocation[] {loc});
}
 
Example 20
Source Project: big-c   Source File: TestFsDatasetCache.java    License: Apache License 2.0 4 votes vote down vote up
private static DatanodeCommand[] cacheBlocks(HdfsBlockLocation[] locs) {
  return new DatanodeCommand[] {
      getResponse(locs, DatanodeProtocol.DNA_CACHE)
  };
}
 
Example 21
Source Project: big-c   Source File: TestFsDatasetCache.java    License: Apache License 2.0 4 votes vote down vote up
private static DatanodeCommand[] uncacheBlock(HdfsBlockLocation loc) {
  return uncacheBlocks(new HdfsBlockLocation[] {loc});
}
 
Example 22
Source Project: big-c   Source File: TestFsDatasetCache.java    License: Apache License 2.0 4 votes vote down vote up
private static DatanodeCommand[] uncacheBlocks(HdfsBlockLocation[] locs) {
  return new DatanodeCommand[] {
      getResponse(locs, DatanodeProtocol.DNA_UNCACHE)
  };
}
 
Example 23
Source Project: big-c   Source File: TestFsDatasetCache.java    License: Apache License 2.0 4 votes vote down vote up
@Test(timeout=600000)
public void testFilesExceedMaxLockedMemory() throws Exception {
  LOG.info("beginning testFilesExceedMaxLockedMemory");

  // Create some test files that will exceed total cache capacity
  final int numFiles = 5;
  final long fileSize = CACHE_CAPACITY / (numFiles-1);

  final Path[] testFiles = new Path[numFiles];
  final HdfsBlockLocation[][] fileLocs = new HdfsBlockLocation[numFiles][];
  final long[] fileSizes = new long[numFiles];
  for (int i=0; i<numFiles; i++) {
    testFiles[i] = new Path("/testFilesExceedMaxLockedMemory-" + i);
    DFSTestUtil.createFile(fs, testFiles[i], fileSize, (short)1, 0xDFAl);
    fileLocs[i] = (HdfsBlockLocation[])fs.getFileBlockLocations(
        testFiles[i], 0, fileSize);
    // Get the file size (sum of blocks)
    long[] sizes = getBlockSizes(fileLocs[i]);
    for (int j=0; j<sizes.length; j++) {
      fileSizes[i] += sizes[j];
    }
  }

  // Cache the first n-1 files
  long total = 0;
  DFSTestUtil.verifyExpectedCacheUsage(0, 0, fsd);
  for (int i=0; i<numFiles-1; i++) {
    setHeartbeatResponse(cacheBlocks(fileLocs[i]));
    total = DFSTestUtil.verifyExpectedCacheUsage(
        rounder.round(total + fileSizes[i]), 4 * (i + 1), fsd);
  }

  // nth file should hit a capacity exception
  final LogVerificationAppender appender = new LogVerificationAppender();
  final Logger logger = Logger.getRootLogger();
  logger.addAppender(appender);
  setHeartbeatResponse(cacheBlocks(fileLocs[numFiles-1]));

  GenericTestUtils.waitFor(new Supplier<Boolean>() {
    @Override
    public Boolean get() {
      int lines = appender.countLinesWithMessage(
          "more bytes in the cache: " +
          DFSConfigKeys.DFS_DATANODE_MAX_LOCKED_MEMORY_KEY);
      return lines > 0;
    }
  }, 500, 30000);
  // Also check the metrics for the failure
  assertTrue("Expected more than 0 failed cache attempts",
      fsd.getNumBlocksFailedToCache() > 0);

  // Uncache the n-1 files
  int curCachedBlocks = 16;
  for (int i=0; i<numFiles-1; i++) {
    setHeartbeatResponse(uncacheBlocks(fileLocs[i]));
    long uncachedBytes = rounder.round(fileSizes[i]);
    total -= uncachedBytes;
    curCachedBlocks -= uncachedBytes / BLOCK_SIZE;
    DFSTestUtil.verifyExpectedCacheUsage(total, curCachedBlocks, fsd);
  }
  LOG.info("finishing testFilesExceedMaxLockedMemory");
}