HDFS-10861. Refactor StripeReaders and use ECChunk version decode API. Contributed by Sammi Chen

This commit is contained in:
Kai Zheng 2016-09-21 21:34:48 +08:00
parent 2b66d9ec5b
commit 734d54c1a8
10 changed files with 844 additions and 678 deletions

View File

@ -29,6 +29,9 @@ public class ECChunk {
private ByteBuffer chunkBuffer;
// TODO: should be in a more general flags
private boolean allZero = false;
/**
* Wrapping a ByteBuffer
* @param buffer buffer to be wrapped by the chunk
@ -37,6 +40,13 @@ public class ECChunk {
this.chunkBuffer = buffer;
}
public ECChunk(ByteBuffer buffer, int offset, int len) {
ByteBuffer tmp = buffer.duplicate();
tmp.position(offset);
tmp.limit(offset + len);
this.chunkBuffer = tmp.slice();
}
/**
* Wrapping a bytes array
* @param buffer buffer to be wrapped by the chunk
@ -45,6 +55,18 @@ public class ECChunk {
this.chunkBuffer = ByteBuffer.wrap(buffer);
}
public ECChunk(byte[] buffer, int offset, int len) {
this.chunkBuffer = ByteBuffer.wrap(buffer, offset, len);
}
public boolean isAllZero() {
return allZero;
}
public void setAllZero(boolean allZero) {
this.allZero = allZero;
}
/**
* Convert to ByteBuffer
* @return ByteBuffer

View File

@ -115,6 +115,9 @@ final class CoderUtil {
buffers[i] = null;
} else {
buffers[i] = chunk.getBuffer();
if (chunk.isAllZero()) {
CoderUtil.resetBuffer(buffers[i], buffers[i].remaining());
}
}
}

View File

@ -240,7 +240,7 @@ public class DFSInputStream extends FSInputStream
Iterator<LocatedBlock> oldIter = locatedBlocks.getLocatedBlocks().iterator();
Iterator<LocatedBlock> newIter = newInfo.getLocatedBlocks().iterator();
while (oldIter.hasNext() && newIter.hasNext()) {
if (! oldIter.next().getBlock().equals(newIter.next().getBlock())) {
if (!oldIter.next().getBlock().equals(newIter.next().getBlock())) {
throw new IOException("Blocklist for " + src + " has changed!");
}
}
@ -677,8 +677,8 @@ public class DFSInputStream extends FSInputStream
if (oneByteBuf == null) {
oneByteBuf = new byte[1];
}
int ret = read( oneByteBuf, 0, 1 );
return ( ret <= 0 ) ? -1 : (oneByteBuf[0] & 0xff);
int ret = read(oneByteBuf, 0, 1);
return (ret <= 0) ? -1 : (oneByteBuf[0] & 0xff);
}
/* This is a used by regular read() and handles ChecksumExceptions.
@ -702,7 +702,7 @@ public class DFSInputStream extends FSInputStream
// retry as many times as seekToNewSource allows.
try {
return reader.readFromBlock(blockReader, len);
} catch ( ChecksumException ce ) {
} catch (ChecksumException ce) {
DFSClient.LOG.warn("Found Checksum error for "
+ getCurrentBlock() + " from " + currentNode
+ " at " + ce.getPos());
@ -710,7 +710,7 @@ public class DFSInputStream extends FSInputStream
retryCurrentNode = false;
// we want to remember which block replicas we have tried
corruptedBlocks.addCorruptedBlock(getCurrentBlock(), currentNode);
} catch ( IOException e ) {
} catch (IOException e) {
if (!retryCurrentNode) {
DFSClient.LOG.warn("Exception while reading from "
+ getCurrentBlock() + " of " + src + " from "
@ -779,7 +779,9 @@ public class DFSInputStream extends FSInputStream
DFSClient.LOG.warn("DFS Read", e);
}
blockEnd = -1;
if (currentNode != null) { addToDeadNodes(currentNode); }
if (currentNode != null) {
addToDeadNodes(currentNode);
}
if (--retries == 0) {
throw e;
}
@ -1397,10 +1399,10 @@ public class DFSInputStream extends FSInputStream
@Override
public long skip(long n) throws IOException {
if ( n > 0 ) {
if (n > 0) {
long curPos = getPos();
long fileLen = getFileLength();
if( n+curPos > fileLen ) {
if (n+curPos > fileLen) {
n = fileLen - curPos;
}
seek(curPos+n);
@ -1550,7 +1552,7 @@ public class DFSInputStream extends FSInputStream
* Get statistics about the reads which this DFSInputStream has done.
*/
public ReadStatistics getReadStatistics() {
return new ReadStatistics(readStatistics);
return readStatistics;
}
/**

View File

@ -17,24 +17,21 @@
*/
package org.apache.hadoop.hdfs;
import com.google.common.base.Preconditions;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.fs.ChecksumException;
import org.apache.hadoop.fs.ReadOption;
import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
import org.apache.hadoop.hdfs.protocol.LocatedBlock;
import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
import org.apache.hadoop.hdfs.protocol.LocatedStripedBlock;
import org.apache.hadoop.hdfs.protocol.datatransfer.InvalidEncryptionKeyException;
import org.apache.hadoop.hdfs.DFSUtilClient.CorruptedBlocks;
import org.apache.hadoop.hdfs.StripeReader.BlockReaderInfo;
import org.apache.hadoop.hdfs.StripeReader.ReaderRetryPolicy;
import org.apache.hadoop.hdfs.util.StripedBlockUtil;
import org.apache.hadoop.hdfs.util.StripedBlockUtil.AlignedStripe;
import org.apache.hadoop.hdfs.util.StripedBlockUtil.StripeRange;
import org.apache.hadoop.io.ByteBufferPool;
import static org.apache.hadoop.hdfs.util.StripedBlockUtil.AlignedStripe;
import static org.apache.hadoop.hdfs.util.StripedBlockUtil.StripingChunk;
import static org.apache.hadoop.hdfs.util.StripedBlockUtil.StripingChunkReadResult;
import org.apache.hadoop.io.ElasticByteBufferPool;
import org.apache.hadoop.io.erasurecode.CodecUtil;
import org.apache.hadoop.hdfs.protocol.ErasureCodingPolicy;
@ -44,7 +41,6 @@ import org.apache.hadoop.io.erasurecode.rawcoder.RawErasureDecoder;
import java.io.EOFException;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Arrays;
@ -53,111 +49,32 @@ import java.util.EnumSet;
import java.util.List;
import java.util.Set;
import java.util.Collection;
import java.util.Map;
import java.util.HashMap;
import java.util.concurrent.CompletionService;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ExecutorCompletionService;
import java.util.concurrent.Callable;
import java.util.concurrent.Future;
import java.util.concurrent.ThreadPoolExecutor;
/**
* DFSStripedInputStream reads from striped block groups
* DFSStripedInputStream reads from striped block groups.
*/
@InterfaceAudience.Private
public class DFSStripedInputStream extends DFSInputStream {
private static class ReaderRetryPolicy {
private int fetchEncryptionKeyTimes = 1;
private int fetchTokenTimes = 1;
void refetchEncryptionKey() {
fetchEncryptionKeyTimes--;
}
void refetchToken() {
fetchTokenTimes--;
}
boolean shouldRefetchEncryptionKey() {
return fetchEncryptionKeyTimes > 0;
}
boolean shouldRefetchToken() {
return fetchTokenTimes > 0;
}
}
/** Used to indicate the buffered data's range in the block group */
private static class StripeRange {
/** start offset in the block group (inclusive) */
final long offsetInBlock;
/** length of the stripe range */
final long length;
StripeRange(long offsetInBlock, long length) {
Preconditions.checkArgument(offsetInBlock >= 0 && length >= 0);
this.offsetInBlock = offsetInBlock;
this.length = length;
}
boolean include(long pos) {
return pos >= offsetInBlock && pos < offsetInBlock + length;
}
}
private static class BlockReaderInfo {
final BlockReader reader;
final DatanodeInfo datanode;
/**
* when initializing block readers, their starting offsets are set to the same
* number: the smallest internal block offsets among all the readers. This is
* because it is possible that for some internal blocks we have to read
* "backwards" for decoding purpose. We thus use this offset array to track
* offsets for all the block readers so that we can skip data if necessary.
*/
long blockReaderOffset;
/**
* We use this field to indicate whether we should use this reader. In case
* we hit any issue with this reader, we set this field to true and avoid
* using it for the next stripe.
*/
boolean shouldSkip = false;
BlockReaderInfo(BlockReader reader, DatanodeInfo dn, long offset) {
this.reader = reader;
this.datanode = dn;
this.blockReaderOffset = offset;
}
void setOffset(long offset) {
this.blockReaderOffset = offset;
}
void skip() {
this.shouldSkip = true;
}
}
private static final ByteBufferPool BUFFER_POOL = new ElasticByteBufferPool();
private final BlockReaderInfo[] blockReaders;
private final int cellSize;
private final short dataBlkNum;
private final short parityBlkNum;
private final int groupSize;
/** the buffer for a complete stripe */
/** the buffer for a complete stripe. */
private ByteBuffer curStripeBuf;
private ByteBuffer parityBuf;
private final ErasureCodingPolicy ecPolicy;
private final RawErasureDecoder decoder;
/**
* indicate the start/end offset of the current buffered stripe in the
* block group
* Indicate the start/end offset of the current buffered stripe in the
* block group.
*/
private StripeRange curStripeRange;
private final CompletionService<Void> readingService;
/**
* When warning the user of a lost block in striping mode, we remember the
@ -167,8 +84,8 @@ public class DFSStripedInputStream extends DFSInputStream {
*
* To minimize the overhead, we only store the datanodeUuid in this set
*/
private final Set<String> warnedNodes = Collections.newSetFromMap(
new ConcurrentHashMap<String, Boolean>());
private final Set<String> warnedNodes =
Collections.newSetFromMap(new ConcurrentHashMap<>());
DFSStripedInputStream(DFSClient dfsClient, String src,
boolean verifyChecksum, ErasureCodingPolicy ecPolicy,
@ -183,8 +100,6 @@ public class DFSStripedInputStream extends DFSInputStream {
groupSize = dataBlkNum + parityBlkNum;
blockReaders = new BlockReaderInfo[groupSize];
curStripeRange = new StripeRange(0, 0);
readingService =
new ExecutorCompletionService<>(dfsClient.getStripedReadsThreadPool());
ErasureCoderOptions coderOptions = new ErasureCoderOptions(
dataBlkNum, parityBlkNum);
decoder = CodecUtil.createRawDecoder(dfsClient.getConfiguration(),
@ -198,7 +113,7 @@ public class DFSStripedInputStream extends DFSInputStream {
return decoder.preferDirectBuffer();
}
private void resetCurStripeBuffer() {
void resetCurStripeBuffer() {
if (curStripeBuf == null) {
curStripeBuf = BUFFER_POOL.getBuffer(useDirectBuffer(),
cellSize * dataBlkNum);
@ -207,7 +122,7 @@ public class DFSStripedInputStream extends DFSInputStream {
curStripeRange = new StripeRange(0, 0);
}
private ByteBuffer getParityBuffer() {
protected ByteBuffer getParityBuffer() {
if (parityBuf == null) {
parityBuf = BUFFER_POOL.getBuffer(useDirectBuffer(),
cellSize * parityBlkNum);
@ -216,6 +131,29 @@ public class DFSStripedInputStream extends DFSInputStream {
return parityBuf;
}
protected ByteBuffer getCurStripeBuf() {
return curStripeBuf;
}
protected String getSrc() {
return src;
}
protected DFSClient getDFSClient() {
return dfsClient;
}
protected LocatedBlocks getLocatedBlocks() {
return locatedBlocks;
}
protected ByteBufferPool getBufferPool() {
return BUFFER_POOL;
}
protected ThreadPoolExecutor getStripedReadsThreadPool(){
return dfsClient.getStripedReadsThreadPool();
}
/**
* When seeking into a new block group, create blockReader for each internal
* block in the group.
@ -268,7 +206,7 @@ public class DFSStripedInputStream extends DFSInputStream {
blockEnd = -1;
}
private void closeReader(BlockReaderInfo readerInfo) {
protected void closeReader(BlockReaderInfo readerInfo) {
if (readerInfo != null) {
if (readerInfo.reader != null) {
try {
@ -288,6 +226,59 @@ public class DFSStripedInputStream extends DFSInputStream {
return pos - currentLocatedBlock.getStartOffset();
}
boolean createBlockReader(LocatedBlock block, long offsetInBlock,
LocatedBlock[] targetBlocks, BlockReaderInfo[] readerInfos,
int chunkIndex) throws IOException {
BlockReader reader = null;
final ReaderRetryPolicy retry = new ReaderRetryPolicy();
DFSInputStream.DNAddrPair dnInfo =
new DFSInputStream.DNAddrPair(null, null, null);
while (true) {
try {
// the cached block location might have been re-fetched, so always
// get it from cache.
block = refreshLocatedBlock(block);
targetBlocks[chunkIndex] = block;
// internal block has one location, just rule out the deadNodes
dnInfo = getBestNodeDNAddrPair(block, null);
if (dnInfo == null) {
break;
}
reader = getBlockReader(block, offsetInBlock,
block.getBlockSize() - offsetInBlock,
dnInfo.addr, dnInfo.storageType, dnInfo.info);
} catch (IOException e) {
if (e instanceof InvalidEncryptionKeyException &&
retry.shouldRefetchEncryptionKey()) {
DFSClient.LOG.info("Will fetch a new encryption key and retry, "
+ "encryption key was invalid when connecting to " + dnInfo.addr
+ " : " + e);
dfsClient.clearDataEncryptionKey();
retry.refetchEncryptionKey();
} else if (retry.shouldRefetchToken() &&
tokenRefetchNeeded(e, dnInfo.addr)) {
fetchBlockAt(block.getStartOffset());
retry.refetchToken();
} else {
//TODO: handles connection issues
DFSClient.LOG.warn("Failed to connect to " + dnInfo.addr + " for " +
"block" + block.getBlock(), e);
// re-fetch the block in case the block has been moved
fetchBlockAt(block.getStartOffset());
addToDeadNodes(dnInfo.info);
}
}
if (reader != null) {
readerInfos[chunkIndex] =
new BlockReaderInfo(reader, dnInfo.info, offsetInBlock);
return true;
}
}
return false;
}
/**
* Read a new stripe covering the current position, and store the data in the
* {@link #curStripeBuf}.
@ -303,20 +294,20 @@ public class DFSStripedInputStream extends DFSInputStream {
final int stripeBufOffset = (int) (offsetInBlockGroup % stripeLen);
final int stripeLimit = (int) Math.min(currentLocatedBlock.getBlockSize()
- (stripeIndex * stripeLen), stripeLen);
StripeRange stripeRange = new StripeRange(offsetInBlockGroup,
stripeLimit - stripeBufOffset);
StripeRange stripeRange =
new StripeRange(offsetInBlockGroup, stripeLimit - stripeBufOffset);
LocatedStripedBlock blockGroup = (LocatedStripedBlock) currentLocatedBlock;
AlignedStripe[] stripes = StripedBlockUtil.divideOneStripe(ecPolicy,
cellSize, blockGroup, offsetInBlockGroup,
offsetInBlockGroup + stripeRange.length - 1, curStripeBuf);
offsetInBlockGroup + stripeRange.getLength() - 1, curStripeBuf);
final LocatedBlock[] blks = StripedBlockUtil.parseStripedBlockGroup(
blockGroup, cellSize, dataBlkNum, parityBlkNum);
// read the whole stripe
for (AlignedStripe stripe : stripes) {
// Parse group to get chosen DN location
StripeReader sreader = new StatefulStripeReader(readingService, stripe,
blks, blockReaders, corruptedBlocks);
StripeReader sreader = new StatefulStripeReader(stripe, ecPolicy, blks,
blockReaders, corruptedBlocks, decoder, this);
sreader.readStripe();
}
curStripeBuf.position(stripeBufOffset);
@ -324,69 +315,8 @@ public class DFSStripedInputStream extends DFSInputStream {
curStripeRange = stripeRange;
}
private Callable<Void> readCells(final BlockReader reader,
final DatanodeInfo datanode, final long currentReaderOffset,
final long targetReaderOffset, final ByteBufferStrategy[] strategies,
final ExtendedBlock currentBlock,
final CorruptedBlocks corruptedBlocks) {
return new Callable<Void>() {
@Override
public Void call() throws Exception {
// reader can be null if getBlockReaderWithRetry failed or
// the reader hit exception before
if (reader == null) {
throw new IOException("The BlockReader is null. " +
"The BlockReader creation failed or the reader hit exception.");
}
Preconditions.checkState(currentReaderOffset <= targetReaderOffset);
if (currentReaderOffset < targetReaderOffset) {
long skipped = reader.skip(targetReaderOffset - currentReaderOffset);
Preconditions.checkState(
skipped == targetReaderOffset - currentReaderOffset);
}
int result = 0;
for (ByteBufferStrategy strategy : strategies) {
result += readToBuffer(reader, datanode, strategy, currentBlock,
corruptedBlocks);
}
return null;
}
};
}
private int readToBuffer(BlockReader blockReader,
DatanodeInfo currentNode, ByteBufferStrategy strategy,
ExtendedBlock currentBlock,
CorruptedBlocks corruptedBlocks)
throws IOException {
final int targetLength = strategy.getTargetLength();
int length = 0;
try {
while (length < targetLength) {
int ret = strategy.readFromBlock(blockReader);
if (ret < 0) {
throw new IOException("Unexpected EOS from the reader");
}
length += ret;
}
return length;
} catch (ChecksumException ce) {
DFSClient.LOG.warn("Found Checksum error for "
+ currentBlock + " from " + currentNode
+ " at " + ce.getPos());
// we want to remember which block replicas we have tried
corruptedBlocks.addCorruptedBlock(currentBlock, currentNode);
throw ce;
} catch (IOException e) {
DFSClient.LOG.warn("Exception while reading from "
+ currentBlock + " of " + src + " from "
+ currentNode, e);
throw e;
}
}
/**
* Seek to a new arbitrary location
* Seek to a new arbitrary location.
*/
@Override
public synchronized void seek(long targetPos) throws IOException {
@ -469,7 +399,7 @@ public class DFSStripedInputStream extends DFSInputStream {
}
/**
* Copy the data from {@link #curStripeBuf} into the given buffer
* Copy the data from {@link #curStripeBuf} into the given buffer.
* @param strategy the ReaderStrategy containing the given buffer
* @param length target length
* @return number of bytes copied
@ -530,17 +460,19 @@ public class DFSStripedInputStream extends DFSInputStream {
AlignedStripe[] stripes = StripedBlockUtil.divideByteRangeIntoStripes(
ecPolicy, cellSize, blockGroup, start, end, buf);
CompletionService<Void> readService = new ExecutorCompletionService<>(
dfsClient.getStripedReadsThreadPool());
final LocatedBlock[] blks = StripedBlockUtil.parseStripedBlockGroup(
blockGroup, cellSize, dataBlkNum, parityBlkNum);
final BlockReaderInfo[] preaderInfos = new BlockReaderInfo[groupSize];
try {
for (AlignedStripe stripe : stripes) {
// Parse group to get chosen DN location
StripeReader preader = new PositionStripeReader(readService, stripe,
blks, preaderInfos, corruptedBlocks);
StripeReader preader = new PositionStripeReader(stripe, ecPolicy, blks,
preaderInfos, corruptedBlocks, decoder, this);
try {
preader.readStripe();
} finally {
preader.close();
}
}
buf.position(buf.position() + (int)(end - start + 1));
} finally {
@ -570,376 +502,6 @@ public class DFSStripedInputStream extends DFSInputStream {
}
}
/**
* The reader for reading a complete {@link AlignedStripe}. Note that an
* {@link AlignedStripe} may cross multiple stripes with cellSize width.
*/
private abstract class StripeReader {
final Map<Future<Void>, Integer> futures = new HashMap<>();
final AlignedStripe alignedStripe;
final CompletionService<Void> service;
final LocatedBlock[] targetBlocks;
final CorruptedBlocks corruptedBlocks;
final BlockReaderInfo[] readerInfos;
StripeReader(CompletionService<Void> service, AlignedStripe alignedStripe,
LocatedBlock[] targetBlocks, BlockReaderInfo[] readerInfos,
CorruptedBlocks corruptedBlocks) {
this.service = service;
this.alignedStripe = alignedStripe;
this.targetBlocks = targetBlocks;
this.readerInfos = readerInfos;
this.corruptedBlocks = corruptedBlocks;
}
/** prepare all the data chunks */
abstract void prepareDecodeInputs();
/** prepare the parity chunk and block reader if necessary */
abstract boolean prepareParityChunk(int index);
abstract void decode();
void updateState4SuccessRead(StripingChunkReadResult result) {
Preconditions.checkArgument(
result.state == StripingChunkReadResult.SUCCESSFUL);
readerInfos[result.index].setOffset(alignedStripe.getOffsetInBlock()
+ alignedStripe.getSpanInBlock());
}
private void checkMissingBlocks() throws IOException {
if (alignedStripe.missingChunksNum > parityBlkNum) {
clearFutures(futures.keySet());
throw new IOException(alignedStripe.missingChunksNum
+ " missing blocks, the stripe is: " + alignedStripe
+ "; locatedBlocks is: " + locatedBlocks);
}
}
/**
* We need decoding. Thus go through all the data chunks and make sure we
* submit read requests for all of them.
*/
private void readDataForDecoding() throws IOException {
prepareDecodeInputs();
for (int i = 0; i < dataBlkNum; i++) {
Preconditions.checkNotNull(alignedStripe.chunks[i]);
if (alignedStripe.chunks[i].state == StripingChunk.REQUESTED) {
if (!readChunk(targetBlocks[i], i)) {
alignedStripe.missingChunksNum++;
}
}
}
checkMissingBlocks();
}
void readParityChunks(int num) throws IOException {
for (int i = dataBlkNum, j = 0; i < dataBlkNum + parityBlkNum && j < num;
i++) {
if (alignedStripe.chunks[i] == null) {
if (prepareParityChunk(i) && readChunk(targetBlocks[i], i)) {
j++;
} else {
alignedStripe.missingChunksNum++;
}
}
}
checkMissingBlocks();
}
boolean createBlockReader(LocatedBlock block, int chunkIndex)
throws IOException {
BlockReader reader = null;
final ReaderRetryPolicy retry = new ReaderRetryPolicy();
DNAddrPair dnInfo = new DNAddrPair(null, null, null);
while(true) {
try {
// the cached block location might have been re-fetched, so always
// get it from cache.
block = refreshLocatedBlock(block);
targetBlocks[chunkIndex] = block;
// internal block has one location, just rule out the deadNodes
dnInfo = getBestNodeDNAddrPair(block, null);
if (dnInfo == null) {
break;
}
reader = getBlockReader(block, alignedStripe.getOffsetInBlock(),
block.getBlockSize() - alignedStripe.getOffsetInBlock(),
dnInfo.addr, dnInfo.storageType, dnInfo.info);
} catch (IOException e) {
if (e instanceof InvalidEncryptionKeyException &&
retry.shouldRefetchEncryptionKey()) {
DFSClient.LOG.info("Will fetch a new encryption key and retry, "
+ "encryption key was invalid when connecting to " + dnInfo.addr
+ " : " + e);
dfsClient.clearDataEncryptionKey();
retry.refetchEncryptionKey();
} else if (retry.shouldRefetchToken() &&
tokenRefetchNeeded(e, dnInfo.addr)) {
fetchBlockAt(block.getStartOffset());
retry.refetchToken();
} else {
//TODO: handles connection issues
DFSClient.LOG.warn("Failed to connect to " + dnInfo.addr + " for " +
"block" + block.getBlock(), e);
// re-fetch the block in case the block has been moved
fetchBlockAt(block.getStartOffset());
addToDeadNodes(dnInfo.info);
}
}
if (reader != null) {
readerInfos[chunkIndex] = new BlockReaderInfo(reader, dnInfo.info,
alignedStripe.getOffsetInBlock());
return true;
}
}
return false;
}
private ByteBufferStrategy[] getReadStrategies(StripingChunk chunk) {
if (chunk.useByteBuffer()) {
ByteBufferStrategy strategy = new ByteBufferStrategy(
chunk.getByteBuffer(), readStatistics, dfsClient);
return new ByteBufferStrategy[]{strategy};
} else {
ByteBufferStrategy[] strategies =
new ByteBufferStrategy[chunk.getChunkBuffer().getSlices().size()];
for (int i = 0; i < strategies.length; i++) {
ByteBuffer buffer = chunk.getChunkBuffer().getSlice(i);
strategies[i] =
new ByteBufferStrategy(buffer, readStatistics, dfsClient);
}
return strategies;
}
}
boolean readChunk(final LocatedBlock block, int chunkIndex)
throws IOException {
final StripingChunk chunk = alignedStripe.chunks[chunkIndex];
if (block == null) {
chunk.state = StripingChunk.MISSING;
return false;
}
if (readerInfos[chunkIndex] == null) {
if (!createBlockReader(block, chunkIndex)) {
chunk.state = StripingChunk.MISSING;
return false;
}
} else if (readerInfos[chunkIndex].shouldSkip) {
chunk.state = StripingChunk.MISSING;
return false;
}
chunk.state = StripingChunk.PENDING;
Callable<Void> readCallable = readCells(readerInfos[chunkIndex].reader,
readerInfos[chunkIndex].datanode,
readerInfos[chunkIndex].blockReaderOffset,
alignedStripe.getOffsetInBlock(), getReadStrategies(chunk),
block.getBlock(), corruptedBlocks);
Future<Void> request = service.submit(readCallable);
futures.put(request, chunkIndex);
return true;
}
/** read the whole stripe. do decoding if necessary */
void readStripe() throws IOException {
for (int i = 0; i < dataBlkNum; i++) {
if (alignedStripe.chunks[i] != null &&
alignedStripe.chunks[i].state != StripingChunk.ALLZERO) {
if (!readChunk(targetBlocks[i], i)) {
alignedStripe.missingChunksNum++;
}
}
}
// There are missing block locations at this stage. Thus we need to read
// the full stripe and one more parity block.
if (alignedStripe.missingChunksNum > 0) {
checkMissingBlocks();
readDataForDecoding();
// read parity chunks
readParityChunks(alignedStripe.missingChunksNum);
}
// TODO: for a full stripe we can start reading (dataBlkNum + 1) chunks
// Input buffers for potential decode operation, which remains null until
// first read failure
while (!futures.isEmpty()) {
try {
StripingChunkReadResult r = StripedBlockUtil
.getNextCompletedStripedRead(service, futures, 0);
if (DFSClient.LOG.isDebugEnabled()) {
DFSClient.LOG.debug("Read task returned: " + r + ", for stripe "
+ alignedStripe);
}
StripingChunk returnedChunk = alignedStripe.chunks[r.index];
Preconditions.checkNotNull(returnedChunk);
Preconditions.checkState(returnedChunk.state == StripingChunk.PENDING);
if (r.state == StripingChunkReadResult.SUCCESSFUL) {
returnedChunk.state = StripingChunk.FETCHED;
alignedStripe.fetchedChunksNum++;
updateState4SuccessRead(r);
if (alignedStripe.fetchedChunksNum == dataBlkNum) {
clearFutures(futures.keySet());
break;
}
} else {
returnedChunk.state = StripingChunk.MISSING;
// close the corresponding reader
closeReader(readerInfos[r.index]);
final int missing = alignedStripe.missingChunksNum;
alignedStripe.missingChunksNum++;
checkMissingBlocks();
readDataForDecoding();
readParityChunks(alignedStripe.missingChunksNum - missing);
}
} catch (InterruptedException ie) {
String err = "Read request interrupted";
DFSClient.LOG.error(err);
clearFutures(futures.keySet());
// Don't decode if read interrupted
throw new InterruptedIOException(err);
}
}
if (alignedStripe.missingChunksNum > 0) {
decode();
}
}
}
class PositionStripeReader extends StripeReader {
private ByteBuffer[] decodeInputs = null;
PositionStripeReader(CompletionService<Void> service,
AlignedStripe alignedStripe, LocatedBlock[] targetBlocks,
BlockReaderInfo[] readerInfos, CorruptedBlocks corruptedBlocks) {
super(service, alignedStripe, targetBlocks, readerInfos,
corruptedBlocks);
}
@Override
void prepareDecodeInputs() {
if (decodeInputs == null) {
decodeInputs = StripedBlockUtil.initDecodeInputs(alignedStripe,
dataBlkNum, parityBlkNum);
}
}
@Override
boolean prepareParityChunk(int index) {
Preconditions.checkState(index >= dataBlkNum &&
alignedStripe.chunks[index] == null);
alignedStripe.chunks[index] = new StripingChunk(decodeInputs[index]);
return true;
}
@Override
void decode() {
StripedBlockUtil.finalizeDecodeInputs(decodeInputs, alignedStripe);
StripedBlockUtil.decodeAndFillBuffer(decodeInputs, alignedStripe,
dataBlkNum, parityBlkNum, decoder);
}
}
class StatefulStripeReader extends StripeReader {
ByteBuffer[] decodeInputs;
StatefulStripeReader(CompletionService<Void> service,
AlignedStripe alignedStripe, LocatedBlock[] targetBlocks,
BlockReaderInfo[] readerInfos, CorruptedBlocks corruptedBlocks) {
super(service, alignedStripe, targetBlocks, readerInfos,
corruptedBlocks);
}
@Override
void prepareDecodeInputs() {
if (decodeInputs == null) {
decodeInputs = new ByteBuffer[dataBlkNum + parityBlkNum];
final ByteBuffer cur;
synchronized (DFSStripedInputStream.this) {
cur = curStripeBuf.duplicate();
}
StripedBlockUtil.VerticalRange range = alignedStripe.range;
for (int i = 0; i < dataBlkNum; i++) {
cur.limit(cur.capacity());
int pos = (int) (range.offsetInBlock % cellSize + cellSize * i);
cur.position(pos);
cur.limit((int) (pos + range.spanInBlock));
decodeInputs[i] = cur.slice();
if (alignedStripe.chunks[i] == null) {
alignedStripe.chunks[i] = new StripingChunk(decodeInputs[i]);
}
}
}
}
@Override
boolean prepareParityChunk(int index) {
Preconditions.checkState(index >= dataBlkNum
&& alignedStripe.chunks[index] == null);
if (blockReaders[index] != null && blockReaders[index].shouldSkip) {
alignedStripe.chunks[index] = new StripingChunk(StripingChunk.MISSING);
// we have failed the block reader before
return false;
}
final int parityIndex = index - dataBlkNum;
ByteBuffer buf = getParityBuffer().duplicate();
buf.position(cellSize * parityIndex);
buf.limit(cellSize * parityIndex + (int) alignedStripe.range.spanInBlock);
decodeInputs[index] = buf.slice();
alignedStripe.chunks[index] = new StripingChunk(decodeInputs[index]);
return true;
}
@Override
void decode() {
final int span = (int) alignedStripe.getSpanInBlock();
for (int i = 0; i < alignedStripe.chunks.length; i++) {
if (alignedStripe.chunks[i] != null &&
alignedStripe.chunks[i].state == StripingChunk.ALLZERO) {
for (int j = 0; j < span; j++) {
decodeInputs[i].put((byte) 0);
}
decodeInputs[i].flip();
} else if (alignedStripe.chunks[i] != null &&
alignedStripe.chunks[i].state == StripingChunk.FETCHED) {
decodeInputs[i].position(0);
decodeInputs[i].limit(span);
}
}
int[] decodeIndices = new int[parityBlkNum];
int pos = 0;
for (int i = 0; i < alignedStripe.chunks.length; i++) {
if (alignedStripe.chunks[i] != null &&
alignedStripe.chunks[i].state == StripingChunk.MISSING) {
if (i < dataBlkNum) {
decodeIndices[pos++] = i;
} else {
decodeInputs[i] = null;
}
}
}
decodeIndices = Arrays.copyOf(decodeIndices, pos);
final int decodeChunkNum = decodeIndices.length;
ByteBuffer[] outputs = new ByteBuffer[decodeChunkNum];
for (int i = 0; i < decodeChunkNum; i++) {
outputs[i] = decodeInputs[decodeIndices[i]];
outputs[i].position(0);
outputs[i].limit((int) alignedStripe.range.spanInBlock);
decodeInputs[decodeIndices[i]] = null;
}
decoder.decode(decodeInputs, decodeIndices, outputs);
}
}
/**
* May need online read recovery, zero-copy read doesn't make
* sense, so don't support it.
@ -957,12 +519,4 @@ public class DFSStripedInputStream extends DFSInputStream {
throw new UnsupportedOperationException(
"Not support enhanced byte buffer access.");
}
/** A variation to {@link DFSInputStream#cancelAll} */
private void clearFutures(Collection<Future<Void>> futures) {
for (Future<Void> future : futures) {
future.cancel(false);
}
futures.clear();
}
}

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@ -0,0 +1,104 @@
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hdfs;
import com.google.common.base.Preconditions;
import org.apache.commons.configuration.SystemConfiguration;
import org.apache.hadoop.hdfs.protocol.ErasureCodingPolicy;
import org.apache.hadoop.hdfs.protocol.LocatedBlock;
import org.apache.hadoop.hdfs.util.StripedBlockUtil;
import org.apache.hadoop.hdfs.util.StripedBlockUtil.StripingChunk;
import org.apache.hadoop.hdfs.util.StripedBlockUtil.AlignedStripe;
import org.apache.hadoop.io.erasurecode.ECChunk;
import org.apache.hadoop.io.erasurecode.rawcoder.RawErasureDecoder;
import org.apache.hadoop.hdfs.DFSUtilClient.CorruptedBlocks;
import java.nio.ByteBuffer;
/**
* The reader for reading a complete {@link StripedBlockUtil.AlignedStripe}
* which may cross multiple stripes with cellSize width.
*/
class PositionStripeReader extends StripeReader {
private ByteBuffer codingBuffer;
PositionStripeReader(AlignedStripe alignedStripe,
ErasureCodingPolicy ecPolicy, LocatedBlock[] targetBlocks,
BlockReaderInfo[] readerInfos, CorruptedBlocks corruptedBlocks,
RawErasureDecoder decoder, DFSStripedInputStream dfsStripedInputStream) {
super(alignedStripe, ecPolicy, targetBlocks, readerInfos,
corruptedBlocks, decoder, dfsStripedInputStream);
}
@Override
void prepareDecodeInputs() {
if (codingBuffer == null) {
this.decodeInputs = new ECChunk[dataBlkNum + parityBlkNum];
initDecodeInputs(alignedStripe);
}
}
@Override
boolean prepareParityChunk(int index) {
Preconditions.checkState(index >= dataBlkNum &&
alignedStripe.chunks[index] == null);
alignedStripe.chunks[index] =
new StripingChunk(decodeInputs[index].getBuffer());
return true;
}
@Override
void decode() {
finalizeDecodeInputs();
decodeAndFillBuffer(true);
}
void initDecodeInputs(AlignedStripe alignedStripe) {
int bufLen = (int) alignedStripe.getSpanInBlock();
int bufCount = dataBlkNum + parityBlkNum;
codingBuffer = dfsStripedInputStream.getBufferPool().
getBuffer(useDirectBuffer(), bufLen * bufCount);
ByteBuffer buffer;
for (int i = 0; i < decodeInputs.length; i++) {
buffer = codingBuffer.duplicate();
decodeInputs[i] = new ECChunk(buffer, i * bufLen, bufLen);
}
for (int i = 0; i < dataBlkNum; i++) {
if (alignedStripe.chunks[i] == null) {
alignedStripe.chunks[i] =
new StripingChunk(decodeInputs[i].getBuffer());
}
}
}
void close() {
if (decodeInputs != null) {
for (int i = 0; i < decodeInputs.length; i++) {
decodeInputs[i] = null;
}
}
if (codingBuffer != null) {
dfsStripedInputStream.getBufferPool().putBuffer(codingBuffer);
codingBuffer = null;
}
}
}

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@ -0,0 +1,95 @@
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hdfs;
import com.google.common.base.Preconditions;
import org.apache.hadoop.hdfs.protocol.ErasureCodingPolicy;
import org.apache.hadoop.hdfs.protocol.LocatedBlock;
import org.apache.hadoop.hdfs.util.StripedBlockUtil;
import org.apache.hadoop.hdfs.util.StripedBlockUtil.StripingChunk;
import org.apache.hadoop.hdfs.util.StripedBlockUtil.AlignedStripe;
import org.apache.hadoop.io.erasurecode.ECChunk;
import org.apache.hadoop.io.erasurecode.rawcoder.RawErasureDecoder;
import org.apache.hadoop.hdfs.DFSUtilClient.CorruptedBlocks;
import java.nio.ByteBuffer;
/**
* The reader for reading a complete {@link StripedBlockUtil.AlignedStripe}
* which belongs to a single stripe.
* Reading cross multiple strips is not supported in this reader.
*/
class StatefulStripeReader extends StripeReader {
StatefulStripeReader(AlignedStripe alignedStripe,
ErasureCodingPolicy ecPolicy, LocatedBlock[] targetBlocks,
BlockReaderInfo[] readerInfos, CorruptedBlocks corruptedBlocks,
RawErasureDecoder decoder, DFSStripedInputStream dfsStripedInputStream) {
super(alignedStripe, ecPolicy, targetBlocks, readerInfos,
corruptedBlocks, decoder, dfsStripedInputStream);
}
@Override
void prepareDecodeInputs() {
final ByteBuffer cur;
synchronized (dfsStripedInputStream) {
cur = dfsStripedInputStream.getCurStripeBuf().duplicate();
}
this.decodeInputs = new ECChunk[dataBlkNum + parityBlkNum];
int bufLen = (int) alignedStripe.getSpanInBlock();
int bufOff = (int) alignedStripe.getOffsetInBlock();
for (int i = 0; i < dataBlkNum; i++) {
cur.limit(cur.capacity());
int pos = bufOff % cellSize + cellSize * i;
cur.position(pos);
cur.limit(pos + bufLen);
decodeInputs[i] = new ECChunk(cur.slice(), 0, bufLen);
if (alignedStripe.chunks[i] == null) {
alignedStripe.chunks[i] =
new StripingChunk(decodeInputs[i].getBuffer());
}
}
}
@Override
boolean prepareParityChunk(int index) {
Preconditions.checkState(index >= dataBlkNum
&& alignedStripe.chunks[index] == null);
if (readerInfos[index] != null && readerInfos[index].shouldSkip) {
alignedStripe.chunks[index] = new StripingChunk(StripingChunk.MISSING);
// we have failed the block reader before
return false;
}
final int parityIndex = index - dataBlkNum;
ByteBuffer buf = dfsStripedInputStream.getParityBuffer().duplicate();
buf.position(cellSize * parityIndex);
buf.limit(cellSize * parityIndex + (int) alignedStripe.range.spanInBlock);
decodeInputs[index] =
new ECChunk(buf.slice(), 0, (int) alignedStripe.range.spanInBlock);
alignedStripe.chunks[index] =
new StripingChunk(decodeInputs[index].getBuffer());
return true;
}
@Override
void decode() {
finalizeDecodeInputs();
decodeAndFillBuffer(false);
}
}

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@ -0,0 +1,463 @@
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hdfs;
import com.google.common.base.Preconditions;
import org.apache.hadoop.fs.ChecksumException;
import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
import org.apache.hadoop.hdfs.protocol.ErasureCodingPolicy;
import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
import org.apache.hadoop.hdfs.protocol.LocatedBlock;
import org.apache.hadoop.hdfs.util.StripedBlockUtil;
import org.apache.hadoop.hdfs.util.StripedBlockUtil.StripingChunk;
import org.apache.hadoop.hdfs.util.StripedBlockUtil.AlignedStripe;
import org.apache.hadoop.hdfs.util.StripedBlockUtil.StripingChunkReadResult;
import org.apache.hadoop.io.erasurecode.ECChunk;
import org.apache.hadoop.io.erasurecode.rawcoder.RawErasureDecoder;
import org.apache.hadoop.hdfs.DFSUtilClient.CorruptedBlocks;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.nio.ByteBuffer;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.Callable;
import java.util.concurrent.CompletionService;
import java.util.concurrent.ExecutorCompletionService;
import java.util.concurrent.Future;
/**
* The reader for reading a complete {@link StripedBlockUtil.AlignedStripe}.
* Note that an {@link StripedBlockUtil.AlignedStripe} may cross multiple
* stripes with cellSize width.
*/
abstract class StripeReader {
static class ReaderRetryPolicy {
private int fetchEncryptionKeyTimes = 1;
private int fetchTokenTimes = 1;
void refetchEncryptionKey() {
fetchEncryptionKeyTimes--;
}
void refetchToken() {
fetchTokenTimes--;
}
boolean shouldRefetchEncryptionKey() {
return fetchEncryptionKeyTimes > 0;
}
boolean shouldRefetchToken() {
return fetchTokenTimes > 0;
}
}
static class BlockReaderInfo {
final BlockReader reader;
final DatanodeInfo datanode;
/**
* when initializing block readers, their starting offsets are set to the
* same number: the smallest internal block offsets among all the readers.
* This is because it is possible that for some internal blocks we have to
* read "backwards" for decoding purpose. We thus use this offset array to
* track offsets for all the block readers so that we can skip data if
* necessary.
*/
long blockReaderOffset;
/**
* We use this field to indicate whether we should use this reader. In case
* we hit any issue with this reader, we set this field to true and avoid
* using it for the next stripe.
*/
boolean shouldSkip = false;
BlockReaderInfo(BlockReader reader, DatanodeInfo dn, long offset) {
this.reader = reader;
this.datanode = dn;
this.blockReaderOffset = offset;
}
void setOffset(long offset) {
this.blockReaderOffset = offset;
}
void skip() {
this.shouldSkip = true;
}
}
protected final Map<Future<Void>, Integer> futures = new HashMap<>();
protected final AlignedStripe alignedStripe;
protected final CompletionService<Void> service;
protected final LocatedBlock[] targetBlocks;
protected final CorruptedBlocks corruptedBlocks;
protected final BlockReaderInfo[] readerInfos;
protected final ErasureCodingPolicy ecPolicy;
protected final short dataBlkNum;
protected final short parityBlkNum;
protected final int cellSize;
protected final RawErasureDecoder decoder;
protected final DFSStripedInputStream dfsStripedInputStream;
protected ECChunk[] decodeInputs;
StripeReader(AlignedStripe alignedStripe,
ErasureCodingPolicy ecPolicy, LocatedBlock[] targetBlocks,
BlockReaderInfo[] readerInfos, CorruptedBlocks corruptedBlocks,
RawErasureDecoder decoder,
DFSStripedInputStream dfsStripedInputStream) {
this.alignedStripe = alignedStripe;
this.ecPolicy = ecPolicy;
this.dataBlkNum = (short)ecPolicy.getNumDataUnits();
this.parityBlkNum = (short)ecPolicy.getNumParityUnits();
this.cellSize = ecPolicy.getCellSize();
this.targetBlocks = targetBlocks;
this.readerInfos = readerInfos;
this.corruptedBlocks = corruptedBlocks;
this.decoder = decoder;
this.dfsStripedInputStream = dfsStripedInputStream;
service = new ExecutorCompletionService<>(
dfsStripedInputStream.getStripedReadsThreadPool());
}
/**
* Prepare all the data chunks.
*/
abstract void prepareDecodeInputs();
/**
* Prepare the parity chunk and block reader if necessary.
*/
abstract boolean prepareParityChunk(int index);
/*
* Decode to get the missing data.
*/
abstract void decode();
/*
* Default close do nothing.
*/
void close() {
}
void updateState4SuccessRead(StripingChunkReadResult result) {
Preconditions.checkArgument(
result.state == StripingChunkReadResult.SUCCESSFUL);
readerInfos[result.index].setOffset(alignedStripe.getOffsetInBlock()
+ alignedStripe.getSpanInBlock());
}
private void checkMissingBlocks() throws IOException {
if (alignedStripe.missingChunksNum > parityBlkNum) {
clearFutures();
throw new IOException(alignedStripe.missingChunksNum
+ " missing blocks, the stripe is: " + alignedStripe
+ "; locatedBlocks is: " + dfsStripedInputStream.getLocatedBlocks());
}
}
/**
* We need decoding. Thus go through all the data chunks and make sure we
* submit read requests for all of them.
*/
private void readDataForDecoding() throws IOException {
prepareDecodeInputs();
for (int i = 0; i < dataBlkNum; i++) {
Preconditions.checkNotNull(alignedStripe.chunks[i]);
if (alignedStripe.chunks[i].state == StripingChunk.REQUESTED) {
if (!readChunk(targetBlocks[i], i)) {
alignedStripe.missingChunksNum++;
}
}
}
checkMissingBlocks();
}
void readParityChunks(int num) throws IOException {
for (int i = dataBlkNum, j = 0; i < dataBlkNum + parityBlkNum && j < num;
i++) {
if (alignedStripe.chunks[i] == null) {
if (prepareParityChunk(i) && readChunk(targetBlocks[i], i)) {
j++;
} else {
alignedStripe.missingChunksNum++;
}
}
}
checkMissingBlocks();
}
private ByteBufferStrategy[] getReadStrategies(StripingChunk chunk) {
if (chunk.useByteBuffer()) {
ByteBufferStrategy strategy = new ByteBufferStrategy(
chunk.getByteBuffer(), dfsStripedInputStream.getReadStatistics(),
dfsStripedInputStream.getDFSClient());
return new ByteBufferStrategy[]{strategy};
}
ByteBufferStrategy[] strategies =
new ByteBufferStrategy[chunk.getChunkBuffer().getSlices().size()];
for (int i = 0; i < strategies.length; i++) {
ByteBuffer buffer = chunk.getChunkBuffer().getSlice(i);
strategies[i] = new ByteBufferStrategy(buffer,
dfsStripedInputStream.getReadStatistics(),
dfsStripedInputStream.getDFSClient());
}
return strategies;
}
private int readToBuffer(BlockReader blockReader,
DatanodeInfo currentNode, ByteBufferStrategy strategy,
ExtendedBlock currentBlock) throws IOException {
final int targetLength = strategy.getTargetLength();
int length = 0;
try {
while (length < targetLength) {
int ret = strategy.readFromBlock(blockReader);
if (ret < 0) {
throw new IOException("Unexpected EOS from the reader");
}
length += ret;
}
return length;
} catch (ChecksumException ce) {
DFSClient.LOG.warn("Found Checksum error for "
+ currentBlock + " from " + currentNode
+ " at " + ce.getPos());
// we want to remember which block replicas we have tried
corruptedBlocks.addCorruptedBlock(currentBlock, currentNode);
throw ce;
} catch (IOException e) {
DFSClient.LOG.warn("Exception while reading from "
+ currentBlock + " of " + dfsStripedInputStream.getSrc() + " from "
+ currentNode, e);
throw e;
}
}
private Callable<Void> readCells(final BlockReader reader,
final DatanodeInfo datanode, final long currentReaderOffset,
final long targetReaderOffset, final ByteBufferStrategy[] strategies,
final ExtendedBlock currentBlock) {
return () -> {
// reader can be null if getBlockReaderWithRetry failed or
// the reader hit exception before
if (reader == null) {
throw new IOException("The BlockReader is null. " +
"The BlockReader creation failed or the reader hit exception.");
}
Preconditions.checkState(currentReaderOffset <= targetReaderOffset);
if (currentReaderOffset < targetReaderOffset) {
long skipped = reader.skip(targetReaderOffset - currentReaderOffset);
Preconditions.checkState(
skipped == targetReaderOffset - currentReaderOffset);
}
for (ByteBufferStrategy strategy : strategies) {
readToBuffer(reader, datanode, strategy, currentBlock);
}
return null;
};
}
boolean readChunk(final LocatedBlock block, int chunkIndex)
throws IOException {
final StripingChunk chunk = alignedStripe.chunks[chunkIndex];
if (block == null) {
chunk.state = StripingChunk.MISSING;
return false;
}
if (readerInfos[chunkIndex] == null) {
if (!dfsStripedInputStream.createBlockReader(block,
alignedStripe.getOffsetInBlock(), targetBlocks,
readerInfos, chunkIndex)) {
chunk.state = StripingChunk.MISSING;
return false;
}
} else if (readerInfos[chunkIndex].shouldSkip) {
chunk.state = StripingChunk.MISSING;
return false;
}
chunk.state = StripingChunk.PENDING;
Callable<Void> readCallable = readCells(readerInfos[chunkIndex].reader,
readerInfos[chunkIndex].datanode,
readerInfos[chunkIndex].blockReaderOffset,
alignedStripe.getOffsetInBlock(), getReadStrategies(chunk),
block.getBlock());
Future<Void> request = service.submit(readCallable);
futures.put(request, chunkIndex);
return true;
}
/**
* read the whole stripe. do decoding if necessary
*/
void readStripe() throws IOException {
for (int i = 0; i < dataBlkNum; i++) {
if (alignedStripe.chunks[i] != null &&
alignedStripe.chunks[i].state != StripingChunk.ALLZERO) {
if (!readChunk(targetBlocks[i], i)) {
alignedStripe.missingChunksNum++;
}
}
}
// There are missing block locations at this stage. Thus we need to read
// the full stripe and one more parity block.
if (alignedStripe.missingChunksNum > 0) {
checkMissingBlocks();
readDataForDecoding();
// read parity chunks
readParityChunks(alignedStripe.missingChunksNum);
}
// TODO: for a full stripe we can start reading (dataBlkNum + 1) chunks
// Input buffers for potential decode operation, which remains null until
// first read failure
while (!futures.isEmpty()) {
try {
StripingChunkReadResult r = StripedBlockUtil
.getNextCompletedStripedRead(service, futures, 0);
if (DFSClient.LOG.isDebugEnabled()) {
DFSClient.LOG.debug("Read task returned: " + r + ", for stripe "
+ alignedStripe);
}
StripingChunk returnedChunk = alignedStripe.chunks[r.index];
Preconditions.checkNotNull(returnedChunk);
Preconditions.checkState(returnedChunk.state == StripingChunk.PENDING);
if (r.state == StripingChunkReadResult.SUCCESSFUL) {
returnedChunk.state = StripingChunk.FETCHED;
alignedStripe.fetchedChunksNum++;
updateState4SuccessRead(r);
if (alignedStripe.fetchedChunksNum == dataBlkNum) {
clearFutures();
break;
}
} else {
returnedChunk.state = StripingChunk.MISSING;
// close the corresponding reader
dfsStripedInputStream.closeReader(readerInfos[r.index]);
final int missing = alignedStripe.missingChunksNum;
alignedStripe.missingChunksNum++;
checkMissingBlocks();
readDataForDecoding();
readParityChunks(alignedStripe.missingChunksNum - missing);
}
} catch (InterruptedException ie) {
String err = "Read request interrupted";
DFSClient.LOG.error(err);
clearFutures();
// Don't decode if read interrupted
throw new InterruptedIOException(err);
}
}
if (alignedStripe.missingChunksNum > 0) {
decode();
}
}
/**
* Some fetched {@link StripingChunk} might be stored in original application
* buffer instead of prepared decode input buffers. Some others are beyond
* the range of the internal blocks and should correspond to all zero bytes.
* When all pending requests have returned, this method should be called to
* finalize decode input buffers.
*/
void finalizeDecodeInputs() {
for (int i = 0; i < alignedStripe.chunks.length; i++) {
final StripingChunk chunk = alignedStripe.chunks[i];
if (chunk != null && chunk.state == StripingChunk.FETCHED) {
if (chunk.useChunkBuffer()) {
chunk.getChunkBuffer().copyTo(decodeInputs[i].getBuffer());
} else {
chunk.getByteBuffer().flip();
}
} else if (chunk != null && chunk.state == StripingChunk.ALLZERO) {
decodeInputs[i].setAllZero(true);
}
}
}
/**
* Decode based on the given input buffers and erasure coding policy.
*/
void decodeAndFillBuffer(boolean fillBuffer) {
// Step 1: prepare indices and output buffers for missing data units
int[] decodeIndices = prepareErasedIndices();
final int decodeChunkNum = decodeIndices.length;
ECChunk[] outputs = new ECChunk[decodeChunkNum];
for (int i = 0; i < decodeChunkNum; i++) {
outputs[i] = decodeInputs[decodeIndices[i]];
decodeInputs[decodeIndices[i]] = null;
}
// Step 2: decode into prepared output buffers
decoder.decode(decodeInputs, decodeIndices, outputs);
// Step 3: fill original application buffer with decoded data
if (fillBuffer) {
for (int i = 0; i < decodeIndices.length; i++) {
int missingBlkIdx = decodeIndices[i];
StripingChunk chunk = alignedStripe.chunks[missingBlkIdx];
if (chunk.state == StripingChunk.MISSING && chunk.useChunkBuffer()) {
chunk.getChunkBuffer().copyFrom(outputs[i].getBuffer());
}
}
}
}
/**
* Prepare erased indices.
*/
int[] prepareErasedIndices() {
int[] decodeIndices = new int[parityBlkNum];
int pos = 0;
for (int i = 0; i < alignedStripe.chunks.length; i++) {
if (alignedStripe.chunks[i] != null &&
alignedStripe.chunks[i].state == StripingChunk.MISSING){
decodeIndices[pos++] = i;
}
}
int[] erasedIndices = Arrays.copyOf(decodeIndices, pos);
return erasedIndices;
}
void clearFutures() {
for (Future<Void> future : futures.keySet()) {
future.cancel(false);
}
futures.clear();
}
boolean useDirectBuffer() {
return decoder.preferDirectBuffer();
}
}

View File

@ -22,7 +22,6 @@ import com.google.common.annotations.VisibleForTesting;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.fs.StorageType;
import org.apache.hadoop.hdfs.DFSStripedOutputStream;
import org.apache.hadoop.hdfs.protocol.Block;
import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
@ -32,7 +31,7 @@ import org.apache.hadoop.hdfs.protocol.LocatedStripedBlock;
import com.google.common.base.Preconditions;
import org.apache.hadoop.hdfs.security.token.block.BlockTokenIdentifier;
import org.apache.hadoop.hdfs.protocol.ErasureCodingPolicy;
import org.apache.hadoop.io.erasurecode.rawcoder.RawErasureDecoder;
import org.apache.hadoop.hdfs.DFSStripedOutputStream;
import org.apache.hadoop.security.token.Token;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
@ -76,18 +75,6 @@ public class StripedBlockUtil {
public static final Logger LOG =
LoggerFactory.getLogger(StripedBlockUtil.class);
/**
* Parses a striped block group into individual blocks.
* @param bg The striped block group
* @param ecPolicy The erasure coding policy
* @return An array of the blocks in the group
*/
public static LocatedBlock[] parseStripedBlockGroup(LocatedStripedBlock bg,
ErasureCodingPolicy ecPolicy) {
return parseStripedBlockGroup(bg, ecPolicy.getCellSize(),
ecPolicy.getNumDataUnits(), ecPolicy.getNumParityUnits());
}
/**
* This method parses a striped block group into individual blocks.
*
@ -112,7 +99,7 @@ public class StripedBlockUtil {
}
/**
* This method creates an internal block at the given index of a block group
* This method creates an internal block at the given index of a block group.
*
* @param idxInReturnedLocs The index in the stored locations in the
* {@link LocatedStripedBlock} object
@ -169,7 +156,7 @@ public class StripedBlockUtil {
}
/**
* Get the size of an internal block at the given index of a block group
* Get the size of an internal block at the given index of a block group.
*
* @param dataSize Size of the block group only counting data blocks
* @param cellSize The size of a striping cell
@ -237,7 +224,7 @@ public class StripedBlockUtil {
/**
* Given a byte's offset in an internal block, calculate the offset in
* the block group
* the block group.
*/
public static long offsetInBlkToOffsetInBG(int cellSize, int dataBlkNum,
long offsetInBlk, int idxInBlockGroup) {
@ -248,12 +235,12 @@ public class StripedBlockUtil {
}
/**
* Get the next completed striped read task
* Get the next completed striped read task.
*
* @return {@link StripingChunkReadResult} indicating the status of the read task
* succeeded, and the block index of the task. If the method times
* out without getting any completed read tasks, -1 is returned as
* block index.
* @return {@link StripingChunkReadResult} indicating the status of the read
* task succeeded, and the block index of the task. If the method
* times out without getting any completed read tasks, -1 is
* returned as block index.
* @throws InterruptedException
*/
public static StripingChunkReadResult getNextCompletedStripedRead(
@ -287,7 +274,7 @@ public class StripedBlockUtil {
/**
* Get the total usage of the striped blocks, which is the total of data
* blocks and parity blocks
* blocks and parity blocks.
*
* @param numDataBlkBytes
* Size of the block group only counting data blocks
@ -307,91 +294,6 @@ public class StripedBlockUtil {
return numDataBlkBytes + numParityBlkBytes;
}
/**
* Initialize the decoding input buffers based on the chunk states in an
* {@link AlignedStripe}. For each chunk that was not initially requested,
* schedule a new fetch request with the decoding input buffer as transfer
* destination.
*/
public static ByteBuffer[] initDecodeInputs(AlignedStripe alignedStripe,
int dataBlkNum, int parityBlkNum) {
ByteBuffer[] decodeInputs = new ByteBuffer[dataBlkNum + parityBlkNum];
for (int i = 0; i < decodeInputs.length; i++) {
decodeInputs[i] = ByteBuffer.allocate(
(int) alignedStripe.getSpanInBlock());
}
// read the full data aligned stripe
for (int i = 0; i < dataBlkNum; i++) {
if (alignedStripe.chunks[i] == null) {
alignedStripe.chunks[i] = new StripingChunk(decodeInputs[i]);
}
}
return decodeInputs;
}
/**
* Some fetched {@link StripingChunk} might be stored in original application
* buffer instead of prepared decode input buffers. Some others are beyond
* the range of the internal blocks and should correspond to all zero bytes.
* When all pending requests have returned, this method should be called to
* finalize decode input buffers.
*/
public static void finalizeDecodeInputs(final ByteBuffer[] decodeInputs,
AlignedStripe alignedStripe) {
for (int i = 0; i < alignedStripe.chunks.length; i++) {
final StripingChunk chunk = alignedStripe.chunks[i];
if (chunk != null && chunk.state == StripingChunk.FETCHED) {
if (chunk.useChunkBuffer()) {
chunk.getChunkBuffer().copyTo(decodeInputs[i]);
} else {
chunk.getByteBuffer().flip();
}
} else if (chunk != null && chunk.state == StripingChunk.ALLZERO) {
//ZERO it. Will be better handled in other following issue.
byte[] emptyBytes = new byte[decodeInputs[i].limit()];
decodeInputs[i].put(emptyBytes);
decodeInputs[i].flip();
} else {
decodeInputs[i] = null;
}
}
}
/**
* Decode based on the given input buffers and erasure coding policy.
*/
public static void decodeAndFillBuffer(final ByteBuffer[] decodeInputs,
AlignedStripe alignedStripe, int dataBlkNum, int parityBlkNum,
RawErasureDecoder decoder) {
// Step 1: prepare indices and output buffers for missing data units
int[] decodeIndices = new int[parityBlkNum];
int pos = 0;
for (int i = 0; i < dataBlkNum; i++) {
if (alignedStripe.chunks[i] != null &&
alignedStripe.chunks[i].state == StripingChunk.MISSING){
decodeIndices[pos++] = i;
}
}
decodeIndices = Arrays.copyOf(decodeIndices, pos);
ByteBuffer[] decodeOutputs = new ByteBuffer[decodeIndices.length];
for (int i = 0; i < decodeOutputs.length; i++) {
decodeOutputs[i] = ByteBuffer.allocate(
(int) alignedStripe.getSpanInBlock());
}
// Step 2: decode into prepared output buffers
decoder.decode(decodeInputs, decodeIndices, decodeOutputs);
// Step 3: fill original application buffer with decoded data
for (int i = 0; i < decodeIndices.length; i++) {
int missingBlkIdx = decodeIndices[i];
StripingChunk chunk = alignedStripe.chunks[missingBlkIdx];
if (chunk.state == StripingChunk.MISSING && chunk.useChunkBuffer()) {
chunk.getChunkBuffer().copyFrom(decodeOutputs[i]);
}
}
}
/**
* Similar functionality with {@link #divideByteRangeIntoStripes}, but is used
* by stateful read and uses ByteBuffer as reading target buffer. Besides the
@ -485,7 +387,7 @@ public class StripedBlockUtil {
/**
* Map the logical byte range to a set of inclusive {@link StripingCell}
* instances, each representing the overlap of the byte range to a cell
* used by {@link DFSStripedOutputStream} in encoding
* used by {@link DFSStripedOutputStream} in encoding.
*/
@VisibleForTesting
private static StripingCell[] getStripingCellsOfByteRange(
@ -530,7 +432,7 @@ public class StripedBlockUtil {
int dataBlkNum = ecPolicy.getNumDataUnits();
int parityBlkNum = ecPolicy.getNumParityUnits();
VerticalRange ranges[] = new VerticalRange[dataBlkNum + parityBlkNum];
VerticalRange[] ranges = new VerticalRange[dataBlkNum + parityBlkNum];
long earliestStart = Long.MAX_VALUE;
long latestEnd = -1;
@ -675,7 +577,7 @@ public class StripedBlockUtil {
@VisibleForTesting
static class StripingCell {
final ErasureCodingPolicy ecPolicy;
/** Logical order in a block group, used when doing I/O to a block group */
/** Logical order in a block group, used when doing I/O to a block group. */
final int idxInBlkGroup;
final int idxInInternalBlk;
final int idxInStripe;
@ -738,7 +640,7 @@ public class StripedBlockUtil {
*/
public static class AlignedStripe {
public VerticalRange range;
/** status of each chunk in the stripe */
/** status of each chunk in the stripe. */
public final StripingChunk[] chunks;
public int fetchedChunksNum = 0;
public int missingChunksNum = 0;
@ -790,9 +692,9 @@ public class StripedBlockUtil {
* +-----+
*/
public static class VerticalRange {
/** start offset in the block group (inclusive) */
/** start offset in the block group (inclusive). */
public long offsetInBlock;
/** length of the stripe range */
/** length of the stripe range. */
public long spanInBlock;
public VerticalRange(long offsetInBlock, long length) {
@ -801,7 +703,7 @@ public class StripedBlockUtil {
this.spanInBlock = length;
}
/** whether a position is in the range */
/** whether a position is in the range. */
public boolean include(long pos) {
return pos >= offsetInBlock && pos < offsetInBlock + spanInBlock;
}
@ -915,7 +817,7 @@ public class StripedBlockUtil {
/**
* Note: target will be ready-to-read state after the call.
*/
void copyTo(ByteBuffer target) {
public void copyTo(ByteBuffer target) {
for (ByteBuffer slice : slices) {
slice.flip();
target.put(slice);
@ -923,7 +825,7 @@ public class StripedBlockUtil {
target.flip();
}
void copyFrom(ByteBuffer src) {
public void copyFrom(ByteBuffer src) {
ByteBuffer tmp;
int len;
for (ByteBuffer slice : slices) {
@ -970,6 +872,28 @@ public class StripedBlockUtil {
}
}
/** Used to indicate the buffered data's range in the block group. */
public static class StripeRange {
/** start offset in the block group (inclusive). */
final long offsetInBlock;
/** length of the stripe range. */
final long length;
public StripeRange(long offsetInBlock, long length) {
Preconditions.checkArgument(offsetInBlock >= 0 && length >= 0);
this.offsetInBlock = offsetInBlock;
this.length = length;
}
public boolean include(long pos) {
return pos >= offsetInBlock && pos < offsetInBlock + length;
}
public long getLength() {
return length;
}
}
/**
* Check if the information such as IDs and generation stamps in block-i
* match the block group.

View File

@ -283,5 +283,4 @@ public class TestStripedBlockUtil {
}
}
}
}