HDFS-4698. Provide client-side metrics for remote reads, local reads, and short-circuit reads. Contributed by Colin Patrick McCabe.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1481121 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Aaron Myers 2013-05-10 17:58:07 +00:00
parent 1161ceb2c9
commit 4ed1fc58c0
14 changed files with 411 additions and 7 deletions

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@ -844,6 +844,9 @@ Release 2.0.5-beta - UNRELEASED
HDFS-4804. WARN when users set the block balanced preference percent below
0.5 or above 1.0. (Stephen Chu via atm)
HDFS-4698. Provide client-side metrics for remote reads, local reads, and
short-circuit reads. (Colin Patrick McCabe via atm)
OPTIMIZATIONS
BUG FIXES

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@ -1197,6 +1197,24 @@ int hdfsFileIsOpenForRead(hdfsFile file)
return (file->type == INPUT);
}
int hdfsFileGetReadStatistics(hdfsFile file,
struct hdfsReadStatistics **stats)
{
errno = ENOTSUP;
return -1;
}
int64_t hdfsReadStatisticsGetRemoteBytesRead(
const struct hdfsReadStatistics *stats)
{
return stats->totalBytesRead - stats->totalLocalBytesRead;
}
void hdfsFileFreeReadStatistics(struct hdfsReadStatistics *stats)
{
free(stats);
}
int hdfsFileIsOpenForWrite(hdfsFile file)
{
return (file->type == OUTPUT);

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@ -70,4 +70,15 @@ public interface BlockReader extends ByteBufferReadable {
* filled or the next call will return EOF.
*/
int readAll(byte[] buf, int offset, int len) throws IOException;
/**
* @return true only if this is a local read.
*/
boolean isLocal();
/**
* @return true only if this is a short-circuit read.
* All short-circuit reads are also local.
*/
boolean isShortCircuit();
}

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@ -531,4 +531,14 @@ class BlockReaderLocal implements BlockReader {
// We never do network I/O in BlockReaderLocal.
return Integer.MAX_VALUE;
}
@Override
public boolean isLocal() {
return true;
}
@Override
public boolean isShortCircuit() {
return true;
}
}

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@ -700,4 +700,14 @@ class BlockReaderLocalLegacy implements BlockReader {
// We never do network I/O in BlockReaderLocalLegacy.
return Integer.MAX_VALUE;
}
@Override
public boolean isLocal() {
return true;
}
@Override
public boolean isShortCircuit() {
return true;
}
}

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@ -81,7 +81,74 @@ public class DFSInputStream extends FSInputStream implements ByteBufferReadable
private LocatedBlock currentLocatedBlock = null;
private long pos = 0;
private long blockEnd = -1;
private final ReadStatistics readStatistics = new ReadStatistics();
public static class ReadStatistics {
public ReadStatistics() {
this.totalBytesRead = 0;
this.totalLocalBytesRead = 0;
this.totalShortCircuitBytesRead = 0;
}
public ReadStatistics(ReadStatistics rhs) {
this.totalBytesRead = rhs.getTotalBytesRead();
this.totalLocalBytesRead = rhs.getTotalLocalBytesRead();
this.totalShortCircuitBytesRead = rhs.getTotalShortCircuitBytesRead();
}
/**
* @return The total bytes read. This will always be at least as
* high as the other numbers, since it includes all of them.
*/
public long getTotalBytesRead() {
return totalBytesRead;
}
/**
* @return The total local bytes read. This will always be at least
* as high as totalShortCircuitBytesRead, since all short-circuit
* reads are also local.
*/
public long getTotalLocalBytesRead() {
return totalLocalBytesRead;
}
/**
* @return The total short-circuit local bytes read.
*/
public long getTotalShortCircuitBytesRead() {
return totalShortCircuitBytesRead;
}
/**
* @return The total number of bytes read which were not local.
*/
public long getRemoteBytesRead() {
return totalBytesRead - totalLocalBytesRead;
}
void addRemoteBytes(long amt) {
this.totalBytesRead += amt;
}
void addLocalBytes(long amt) {
this.totalBytesRead += amt;
this.totalLocalBytesRead += amt;
}
void addShortCircuitBytes(long amt) {
this.totalBytesRead += amt;
this.totalLocalBytesRead += amt;
this.totalShortCircuitBytesRead += amt;
}
private long totalBytesRead;
private long totalLocalBytesRead;
private long totalShortCircuitBytesRead;
}
private final FileInputStreamCache fileInputStreamCache;
/**
@ -546,9 +613,25 @@ public class DFSInputStream extends FSInputStream implements ByteBufferReadable
* strategy-agnostic.
*/
private interface ReaderStrategy {
public int doRead(BlockReader blockReader, int off, int len) throws ChecksumException, IOException;
public int doRead(BlockReader blockReader, int off, int len,
ReadStatistics readStatistics) throws ChecksumException, IOException;
}
private static void updateReadStatistics(ReadStatistics readStatistics,
int nRead, BlockReader blockReader) {
if (nRead <= 0) return;
if (blockReader.isShortCircuit()) {
readStatistics.totalBytesRead += nRead;
readStatistics.totalLocalBytesRead += nRead;
readStatistics.totalShortCircuitBytesRead += nRead;
} else if (blockReader.isLocal()) {
readStatistics.totalBytesRead += nRead;
readStatistics.totalLocalBytesRead += nRead;
} else {
readStatistics.totalBytesRead += nRead;
}
}
/**
* Used to read bytes into a byte[]
*/
@ -560,8 +643,11 @@ public class DFSInputStream extends FSInputStream implements ByteBufferReadable
}
@Override
public int doRead(BlockReader blockReader, int off, int len) throws ChecksumException, IOException {
return blockReader.read(buf, off, len);
public int doRead(BlockReader blockReader, int off, int len,
ReadStatistics readStatistics) throws ChecksumException, IOException {
int nRead = blockReader.read(buf, off, len);
updateReadStatistics(readStatistics, nRead, blockReader);
return nRead;
}
}
@ -575,13 +661,15 @@ public class DFSInputStream extends FSInputStream implements ByteBufferReadable
}
@Override
public int doRead(BlockReader blockReader, int off, int len) throws ChecksumException, IOException {
public int doRead(BlockReader blockReader, int off, int len,
ReadStatistics readStatistics) throws ChecksumException, IOException {
int oldpos = buf.position();
int oldlimit = buf.limit();
boolean success = false;
try {
int ret = blockReader.read(buf);
success = true;
updateReadStatistics(readStatistics, ret, blockReader);
return ret;
} finally {
if (!success) {
@ -613,7 +701,7 @@ public class DFSInputStream extends FSInputStream implements ByteBufferReadable
while (true) {
// retry as many times as seekToNewSource allows.
try {
return reader.doRead(blockReader, off, len);
return reader.doRead(blockReader, off, len, readStatistics);
} catch ( ChecksumException ce ) {
DFSClient.LOG.warn("Found Checksum error for "
+ getCurrentBlock() + " from " + currentNode
@ -1275,4 +1363,11 @@ public class DFSInputStream extends FSInputStream implements ByteBufferReadable
this.addr = addr;
}
}
/**
* Get statistics about the reads which this DFSInputStream has done.
*/
public synchronized ReadStatistics getReadStatistics() {
return new ReadStatistics(readStatistics);
}
}

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@ -40,6 +40,7 @@ import org.apache.hadoop.hdfs.protocol.proto.DataTransferProtos.Status;
import org.apache.hadoop.hdfs.protocolPB.PBHelper;
import org.apache.hadoop.hdfs.security.token.block.BlockTokenIdentifier;
import org.apache.hadoop.io.IOUtils;
import org.apache.hadoop.net.NetUtils;
import org.apache.hadoop.security.token.Token;
import org.apache.hadoop.util.DataChecksum;
@ -78,6 +79,11 @@ public class RemoteBlockReader extends FSInputChecker implements BlockReader {
* at the beginning so that the read can begin on a chunk boundary.
*/
private final long bytesNeededToFinish;
/**
* True if we are reading from a local DataNode.
*/
private final boolean isLocal;
private boolean eos = false;
private boolean sentStatusCode = false;
@ -329,6 +335,9 @@ public class RemoteBlockReader extends FSInputChecker implements BlockReader {
checksum.getChecksumSize() > 0? checksum : null,
checksum.getBytesPerChecksum(),
checksum.getChecksumSize());
this.isLocal = DFSClient.isLocalAddress(NetUtils.
createSocketAddr(datanodeID.getXferAddr()));
this.peer = peer;
this.datanodeID = datanodeID;
@ -477,4 +486,14 @@ public class RemoteBlockReader extends FSInputChecker implements BlockReader {
// to us without doing network I/O.
return DFSClient.TCP_WINDOW_SIZE;
}
@Override
public boolean isLocal() {
return isLocal;
}
@Override
public boolean isShortCircuit() {
return false;
}
}

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@ -44,6 +44,7 @@ import org.apache.hadoop.hdfs.security.token.block.DataEncryptionKey;
import org.apache.hadoop.hdfs.protocolPB.PBHelper;
import org.apache.hadoop.hdfs.security.token.block.BlockTokenIdentifier;
import org.apache.hadoop.hdfs.security.token.block.InvalidBlockTokenException;
import org.apache.hadoop.net.NetUtils;
import org.apache.hadoop.security.token.Token;
import org.apache.hadoop.util.DataChecksum;
@ -106,6 +107,11 @@ public class RemoteBlockReader2 implements BlockReader {
*/
private long bytesNeededToFinish;
/**
* True if we are reading from a local DataNode.
*/
private final boolean isLocal;
private final boolean verifyChecksum;
private boolean sentStatusCode = false;
@ -255,6 +261,8 @@ public class RemoteBlockReader2 implements BlockReader {
DataChecksum checksum, boolean verifyChecksum,
long startOffset, long firstChunkOffset, long bytesToRead, Peer peer,
DatanodeID datanodeID, PeerCache peerCache) {
this.isLocal = DFSClient.isLocalAddress(NetUtils.
createSocketAddr(datanodeID.getXferAddr()));
// Path is used only for printing block and file information in debug
this.peer = peer;
this.datanodeID = datanodeID;
@ -431,4 +439,14 @@ public class RemoteBlockReader2 implements BlockReader {
// to us without doing network I/O.
return DFSClient.TCP_WINDOW_SIZE;
}
@Override
public boolean isLocal() {
return isLocal;
}
@Override
public boolean isShortCircuit() {
return false;
}
}

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@ -68,4 +68,14 @@ public class HdfsDataInputStream extends FSDataInputStream {
public long getVisibleLength() throws IOException {
return ((DFSInputStream) in).getFileLength();
}
/**
* Get statistics about the reads which this DFSInputStream has done.
* Note that because HdfsDataInputStream is buffered, these stats may
* be higher than you would expect just by adding up the number of
* bytes read through HdfsDataInputStream.
*/
public synchronized DFSInputStream.ReadStatistics getReadStatistics() {
return ((DFSInputStream) in).getReadStatistics();
}
}

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@ -214,7 +214,7 @@ public class JspHelper {
new ExtendedBlock(poolId, blockId, 0, genStamp), blockToken,
offsetIntoBlock, amtToRead, true,
"JspHelper", TcpPeerServer.peerFromSocketAndKey(s, encryptionKey),
new DatanodeID(addr.getAddress().toString(),
new DatanodeID(addr.getAddress().getHostAddress(),
addr.getHostName(), poolId, addr.getPort(), 0, 0), null,
null, null, false);

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@ -81,6 +81,93 @@ int hdfsFileIsOpenForRead(hdfsFile file)
return (file->type == INPUT);
}
int hdfsFileGetReadStatistics(hdfsFile file,
struct hdfsReadStatistics **stats)
{
jthrowable jthr;
jobject readStats = NULL;
jvalue jVal;
struct hdfsReadStatistics *s = NULL;
int ret;
JNIEnv* env = getJNIEnv();
if (env == NULL) {
errno = EINTERNAL;
return -1;
}
if (file->type != INPUT) {
ret = EINVAL;
goto done;
}
jthr = invokeMethod(env, &jVal, INSTANCE, file->file,
"org/apache/hadoop/hdfs/client/HdfsDataInputStream",
"getReadStatistics",
"()Lorg/apache/hadoop/hdfs/DFSInputStream$ReadStatistics;");
if (jthr) {
ret = printExceptionAndFree(env, jthr, PRINT_EXC_ALL,
"hdfsFileGetReadStatistics: getReadStatistics failed");
goto done;
}
readStats = jVal.l;
s = malloc(sizeof(struct hdfsReadStatistics));
if (!s) {
ret = ENOMEM;
goto done;
}
jthr = invokeMethod(env, &jVal, INSTANCE, readStats,
"org/apache/hadoop/hdfs/DFSInputStream$ReadStatistics",
"getTotalBytesRead", "()J");
if (jthr) {
ret = printExceptionAndFree(env, jthr, PRINT_EXC_ALL,
"hdfsFileGetReadStatistics: getTotalBytesRead failed");
goto done;
}
s->totalBytesRead = jVal.j;
jthr = invokeMethod(env, &jVal, INSTANCE, readStats,
"org/apache/hadoop/hdfs/DFSInputStream$ReadStatistics",
"getTotalLocalBytesRead", "()J");
if (jthr) {
ret = printExceptionAndFree(env, jthr, PRINT_EXC_ALL,
"hdfsFileGetReadStatistics: getTotalLocalBytesRead failed");
goto done;
}
s->totalLocalBytesRead = jVal.j;
jthr = invokeMethod(env, &jVal, INSTANCE, readStats,
"org/apache/hadoop/hdfs/DFSInputStream$ReadStatistics",
"getTotalShortCircuitBytesRead", "()J");
if (jthr) {
ret = printExceptionAndFree(env, jthr, PRINT_EXC_ALL,
"hdfsFileGetReadStatistics: getTotalShortCircuitBytesRead failed");
goto done;
}
s->totalShortCircuitBytesRead = jVal.j;
*stats = s;
s = NULL;
ret = 0;
done:
destroyLocalReference(env, readStats);
free(s);
if (ret) {
errno = ret;
return -1;
}
return 0;
}
int64_t hdfsReadStatisticsGetRemoteBytesRead(
const struct hdfsReadStatistics *stats)
{
return stats->totalBytesRead - stats->totalLocalBytesRead;
}
void hdfsFileFreeReadStatistics(struct hdfsReadStatistics *stats)
{
free(stats);
}
int hdfsFileIsOpenForWrite(hdfsFile file)
{
return (file->type == OUTPUT);

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@ -81,6 +81,43 @@ extern "C" {
*/
int hdfsFileIsOpenForWrite(hdfsFile file);
struct hdfsReadStatistics {
uint64_t totalBytesRead;
uint64_t totalLocalBytesRead;
uint64_t totalShortCircuitBytesRead;
};
/**
* Get read statistics about a file. This is only applicable to files
* opened for reading.
*
* @param file The HDFS file
* @param stats (out parameter) on a successful return, the read
* statistics. Unchanged otherwise. You must free the
* returned statistics with hdfsFileFreeReadStatistics.
* @return 0 if the statistics were successfully returned,
* -1 otherwise. On a failure, please check errno against
* ENOTSUP. webhdfs, LocalFilesystem, and so forth may
* not support read statistics.
*/
int hdfsFileGetReadStatistics(hdfsFile file,
struct hdfsReadStatistics **stats);
/**
* @param stats HDFS read statistics for a file.
*
* @return the number of remote bytes read.
*/
int64_t hdfsReadStatisticsGetRemoteBytesRead(
const struct hdfsReadStatistics *stats);
/**
* Free some HDFS read statistics.
*
* @param stats The HDFS read statistics to free.
*/
void hdfsFileFreeReadStatistics(struct hdfsReadStatistics *stats);
/**
* hdfsConnectAsUser - Connect to a hdfs file system as a specific user
* Connect to the hdfs.

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@ -116,6 +116,7 @@ static int doTestHdfsOperations(struct tlhThreadInfo *ti, hdfsFS fs)
hdfsFile file;
int ret, expected;
hdfsFileInfo *fileInfo;
struct hdfsReadStatistics *readStats = NULL;
snprintf(prefix, sizeof(prefix), "/tlhData%04d", ti->threadIdx);
@ -157,6 +158,12 @@ static int doTestHdfsOperations(struct tlhThreadInfo *ti, hdfsFS fs)
file = hdfsOpenFile(fs, tmp, O_RDONLY, 0, 0, 0);
EXPECT_NONNULL(file);
EXPECT_ZERO(hdfsFileGetReadStatistics(file, &readStats));
errno = 0;
EXPECT_ZERO(readStats->totalBytesRead);
EXPECT_ZERO(readStats->totalLocalBytesRead);
EXPECT_ZERO(readStats->totalShortCircuitBytesRead);
hdfsFileFreeReadStatistics(readStats);
/* TODO: implement readFully and use it here */
ret = hdfsRead(fs, file, tmp, sizeof(tmp));
if (ret < 0) {
@ -169,6 +176,10 @@ static int doTestHdfsOperations(struct tlhThreadInfo *ti, hdfsFS fs)
"it read %d\n", ret, expected);
return EIO;
}
EXPECT_ZERO(hdfsFileGetReadStatistics(file, &readStats));
errno = 0;
EXPECT_INT_EQ(expected, readStats->totalBytesRead);
hdfsFileFreeReadStatistics(readStats);
EXPECT_ZERO(memcmp(prefix, tmp, expected));
EXPECT_ZERO(hdfsCloseFile(fs, file));

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@ -25,14 +25,19 @@ import java.io.RandomAccessFile;
import java.nio.ByteBuffer;
import java.util.concurrent.TimeoutException;
import org.apache.hadoop.hdfs.DFSInputStream.ReadStatistics;
import org.apache.hadoop.fs.ChecksumException;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.client.HdfsDataInputStream;
import org.apache.hadoop.hdfs.protocol.DatanodeID;
import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
import org.apache.hadoop.io.IOUtils;
import org.apache.hadoop.net.unix.DomainSocket;
import org.apache.hadoop.net.unix.TemporarySocketDirectory;
import org.junit.Assert;
import org.junit.Assume;
import org.junit.Test;
public class TestBlockReaderLocal {
@ -339,11 +344,81 @@ public class TestBlockReaderLocal {
}
}
}
@Test
public void testBlockReaderLocalReadCorrupt()
throws IOException {
runBlockReaderLocalTest(new TestBlockReaderLocalReadCorrupt(), true);
runBlockReaderLocalTest(new TestBlockReaderLocalReadCorrupt(), false);
}
@Test(timeout=60000)
public void TestStatisticsForShortCircuitLocalRead() throws Exception {
testStatistics(true);
}
@Test(timeout=60000)
public void TestStatisticsForLocalRead() throws Exception {
testStatistics(false);
}
private void testStatistics(boolean isShortCircuit) throws Exception {
Assume.assumeTrue(DomainSocket.getLoadingFailureReason() == null);
HdfsConfiguration conf = new HdfsConfiguration();
TemporarySocketDirectory sockDir = null;
if (isShortCircuit) {
DFSInputStream.tcpReadsDisabledForTesting = true;
sockDir = new TemporarySocketDirectory();
conf.set(DFSConfigKeys.DFS_DOMAIN_SOCKET_PATH_KEY,
new File(sockDir.getDir(), "TestStatisticsForLocalRead.%d.sock").
getAbsolutePath());
conf.setBoolean(DFSConfigKeys.DFS_CLIENT_READ_SHORTCIRCUIT_KEY, true);
DomainSocket.disableBindPathValidation();
} else {
conf.setBoolean(DFSConfigKeys.DFS_CLIENT_READ_SHORTCIRCUIT_KEY, false);
}
MiniDFSCluster cluster = null;
final Path TEST_PATH = new Path("/a");
final long RANDOM_SEED = 4567L;
FSDataInputStream fsIn = null;
byte original[] = new byte[BlockReaderLocalTest.TEST_LENGTH];
try {
cluster = new MiniDFSCluster.Builder(conf).numDataNodes(1).build();
cluster.waitActive();
FileSystem fs = cluster.getFileSystem();
DFSTestUtil.createFile(fs, TEST_PATH,
BlockReaderLocalTest.TEST_LENGTH, (short)1, RANDOM_SEED);
try {
DFSTestUtil.waitReplication(fs, TEST_PATH, (short)1);
} catch (InterruptedException e) {
Assert.fail("unexpected InterruptedException during " +
"waitReplication: " + e);
} catch (TimeoutException e) {
Assert.fail("unexpected TimeoutException during " +
"waitReplication: " + e);
}
fsIn = fs.open(TEST_PATH);
IOUtils.readFully(fsIn, original, 0,
BlockReaderLocalTest.TEST_LENGTH);
HdfsDataInputStream dfsIn = (HdfsDataInputStream)fsIn;
Assert.assertEquals(BlockReaderLocalTest.TEST_LENGTH,
dfsIn.getReadStatistics().getTotalBytesRead());
Assert.assertEquals(BlockReaderLocalTest.TEST_LENGTH,
dfsIn.getReadStatistics().getTotalLocalBytesRead());
if (isShortCircuit) {
Assert.assertEquals(BlockReaderLocalTest.TEST_LENGTH,
dfsIn.getReadStatistics().getTotalShortCircuitBytesRead());
} else {
Assert.assertEquals(0,
dfsIn.getReadStatistics().getTotalShortCircuitBytesRead());
}
fsIn.close();
fsIn = null;
} finally {
DFSInputStream.tcpReadsDisabledForTesting = false;
if (fsIn != null) fsIn.close();
if (cluster != null) cluster.shutdown();
if (sockDir != null) sockDir.close();
}
}
}