hadoop DFSOutputStream 源码
haddop DFSOutputStream 代码
文件路径：/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DFSOutputStream.java
/**
* 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 java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.nio.ByteBuffer;
import java.nio.channels.ClosedChannelException;
import java.util.EnumSet;
import java.util.concurrent.atomic.AtomicReference;
import org.apache.hadoop.HadoopIllegalArgumentException;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.crypto.CryptoProtocolVersion;
import org.apache.hadoop.fs.CanSetDropBehind;
import org.apache.hadoop.fs.CreateFlag;
import org.apache.hadoop.fs.FSOutputSummer;
import org.apache.hadoop.fs.FileAlreadyExistsException;
import org.apache.hadoop.fs.FileEncryptionInfo;
import org.apache.hadoop.fs.ParentNotDirectoryException;
import org.apache.hadoop.fs.StreamCapabilities;
import org.apache.hadoop.fs.Syncable;
import org.apache.hadoop.fs.impl.StoreImplementationUtils;
import org.apache.hadoop.fs.permission.FsPermission;
import org.apache.hadoop.hdfs.client.HdfsClientConfigKeys;
import org.apache.hadoop.hdfs.client.HdfsDataOutputStream;
import org.apache.hadoop.hdfs.client.HdfsDataOutputStream.SyncFlag;
import org.apache.hadoop.hdfs.client.impl.DfsClientConf;
import org.apache.hadoop.hdfs.protocol.DSQuotaExceededException;
import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
import org.apache.hadoop.hdfs.protocol.LocatedBlock;
import org.apache.hadoop.hdfs.protocol.NSQuotaExceededException;
import org.apache.hadoop.hdfs.protocol.QuotaByStorageTypeExceededException;
import org.apache.hadoop.hdfs.protocol.SnapshotAccessControlException;
import org.apache.hadoop.hdfs.protocol.UnresolvedPathException;
import org.apache.hadoop.hdfs.protocol.datatransfer.PacketHeader;
import org.apache.hadoop.hdfs.protocol.datatransfer.PacketReceiver;
import org.apache.hadoop.hdfs.security.token.block.BlockTokenIdentifier;
import org.apache.hadoop.hdfs.server.datanode.CachingStrategy;
import org.apache.hadoop.hdfs.server.namenode.NotReplicatedYetException;
import org.apache.hadoop.hdfs.server.namenode.RetryStartFileException;
import org.apache.hadoop.hdfs.server.namenode.SafeModeException;
import org.apache.hadoop.hdfs.util.ByteArrayManager;
import org.apache.hadoop.io.EnumSetWritable;
import org.apache.hadoop.io.MultipleIOException;
import org.apache.hadoop.ipc.RemoteException;
import org.apache.hadoop.security.AccessControlException;
import org.apache.hadoop.security.token.Token;
import org.apache.hadoop.util.DataChecksum;
import org.apache.hadoop.util.DataChecksum.Type;
import org.apache.hadoop.util.Progressable;
import org.apache.hadoop.util.Time;
import org.apache.hadoop.tracing.TraceScope;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hadoop.classification.VisibleForTesting;
import org.apache.hadoop.util.Preconditions;
import static org.apache.hadoop.hdfs.client.HdfsClientConfigKeys.Write.RECOVER_LEASE_ON_CLOSE_EXCEPTION_DEFAULT;
import static org.apache.hadoop.hdfs.client.HdfsClientConfigKeys.Write.RECOVER_LEASE_ON_CLOSE_EXCEPTION_KEY;
/****************************************************************
* DFSOutputStream creates files from a stream of bytes.
*
* The client application writes data that is cached internally by
* this stream. Data is broken up into packets, each packet is
* typically 64K in size. A packet comprises of chunks. Each chunk
* is typically 512 bytes and has an associated checksum with it.
*
* When a client application fills up the currentPacket, it is
* enqueued into the dataQueue of DataStreamer. DataStreamer is a
* thread that picks up packets from the dataQueue and sends it to
* the first datanode in the pipeline.
*
****************************************************************/
@InterfaceAudience.Private
public class DFSOutputStream extends FSOutputSummer
implements Syncable, CanSetDropBehind, StreamCapabilities {
static final Logger LOG = LoggerFactory.getLogger(DFSOutputStream.class);
/**
* Number of times to retry creating a file when there are transient
* errors (typically related to encryption zones and KeyProvider operations).
*/
@VisibleForTesting
static final int CREATE_RETRY_COUNT = 10;
@VisibleForTesting
static CryptoProtocolVersion[] SUPPORTED_CRYPTO_VERSIONS =
CryptoProtocolVersion.supported();
protected final DFSClient dfsClient;
protected final ByteArrayManager byteArrayManager;
// closed is accessed by different threads under different locks.
protected volatile boolean closed = false;
protected final String src;
protected final long fileId;
private final String namespace;
private final String uniqKey;
protected final long blockSize;
protected final int bytesPerChecksum;
protected DFSPacket currentPacket = null;
protected DataStreamer streamer;
protected int packetSize = 0; // write packet size, not including the header.
protected int chunksPerPacket = 0;
protected long lastFlushOffset = 0; // offset when flush was invoked
protected long initialFileSize = 0; // at time of file open
private final short blockReplication; // replication factor of file
protected boolean shouldSyncBlock = false; // force blocks to disk upon close
private final EnumSet<AddBlockFlag> addBlockFlags;
protected final AtomicReference<CachingStrategy> cachingStrategy;
private FileEncryptionInfo fileEncryptionInfo;
private int writePacketSize;
private boolean leaseRecovered = false;
/** Use {@link ByteArrayManager} to create buffer for non-heartbeat packets.*/
protected DFSPacket createPacket(int packetSize, int chunksPerPkt,
long offsetInBlock, long seqno, boolean lastPacketInBlock)
throws InterruptedIOException {
final byte[] buf;
final int bufferSize = PacketHeader.PKT_MAX_HEADER_LEN + packetSize;
try {
buf = byteArrayManager.newByteArray(bufferSize);
} catch (InterruptedException ie) {
final InterruptedIOException iioe = new InterruptedIOException(
"seqno=" + seqno);
iioe.initCause(ie);
throw iioe;
}
return new DFSPacket(buf, chunksPerPkt, offsetInBlock, seqno,
getChecksumSize(), lastPacketInBlock);
}
@Override
protected void checkClosed() throws IOException {
if (isClosed()) {
getStreamer().getLastException().throwException4Close();
}
}
//
// returns the list of targets, if any, that is being currently used.
//
@VisibleForTesting
public synchronized DatanodeInfo[] getPipeline() {
if (getStreamer().streamerClosed()) {
return null;
}
DatanodeInfo[] currentNodes = getStreamer().getNodes();
if (currentNodes == null) {
return null;
}
DatanodeInfo[] value = new DatanodeInfo[currentNodes.length];
System.arraycopy(currentNodes, 0, value, 0, currentNodes.length);
return value;
}
/**
* @return the object for computing checksum.
* The type is NULL if checksum is not computed.
*/
private static DataChecksum getChecksum4Compute(DataChecksum checksum,
HdfsFileStatus stat) {
if (DataStreamer.isLazyPersist(stat) && stat.getReplication() == 1) {
// do not compute checksum for writing to single replica to memory
return DataChecksum.newDataChecksum(Type.NULL,
checksum.getBytesPerChecksum());
}
return checksum;
}
private DFSOutputStream(DFSClient dfsClient, String src,
EnumSet<CreateFlag> flag,
Progressable progress, HdfsFileStatus stat, DataChecksum checksum) {
super(getChecksum4Compute(checksum, stat));
this.dfsClient = dfsClient;
this.src = src;
this.fileId = stat.getFileId();
this.namespace = stat.getNamespace();
if (this.namespace == null) {
String defaultKey = dfsClient.getConfiguration().get(
HdfsClientConfigKeys.DFS_OUTPUT_STREAM_UNIQ_DEFAULT_KEY,
HdfsClientConfigKeys.DFS_OUTPUT_STREAM_UNIQ_DEFAULT_KEY_DEFAULT);
this.uniqKey = defaultKey + "_" + this.fileId;
} else {
this.uniqKey = this.namespace + "_" + this.fileId;
}
this.blockSize = stat.getBlockSize();
this.blockReplication = stat.getReplication();
this.fileEncryptionInfo = stat.getFileEncryptionInfo();
this.cachingStrategy = new AtomicReference<>(
dfsClient.getDefaultWriteCachingStrategy());
this.addBlockFlags = EnumSet.noneOf(AddBlockFlag.class);
if (flag.contains(CreateFlag.NO_LOCAL_WRITE)) {
this.addBlockFlags.add(AddBlockFlag.NO_LOCAL_WRITE);
}
if (flag.contains(CreateFlag.NO_LOCAL_RACK)) {
this.addBlockFlags.add(AddBlockFlag.NO_LOCAL_RACK);
}
if (flag.contains(CreateFlag.IGNORE_CLIENT_LOCALITY)) {
this.addBlockFlags.add(AddBlockFlag.IGNORE_CLIENT_LOCALITY);
}
if (progress != null) {
DFSClient.LOG.debug("Set non-null progress callback on DFSOutputStream "
+"{}", src);
}
initWritePacketSize();
this.bytesPerChecksum = checksum.getBytesPerChecksum();
if (bytesPerChecksum <= 0) {
throw new HadoopIllegalArgumentException(
"Invalid value: bytesPerChecksum = " + bytesPerChecksum + " <= 0");
}
if (blockSize % bytesPerChecksum != 0) {
throw new HadoopIllegalArgumentException("Invalid values: "
+ HdfsClientConfigKeys.DFS_BYTES_PER_CHECKSUM_KEY
+ " (=" + bytesPerChecksum + ") must divide block size (=" +
blockSize + ").");
}
this.byteArrayManager = dfsClient.getClientContext().getByteArrayManager();
}
/**
* Ensures the configured writePacketSize never exceeds
* PacketReceiver.MAX_PACKET_SIZE.
*/
private void initWritePacketSize() {
writePacketSize = dfsClient.getConf().getWritePacketSize();
if (writePacketSize > PacketReceiver.MAX_PACKET_SIZE) {
LOG.warn(
"Configured write packet exceeds {} bytes as max,"
+ " using {} bytes.",
PacketReceiver.MAX_PACKET_SIZE, PacketReceiver.MAX_PACKET_SIZE);
writePacketSize = PacketReceiver.MAX_PACKET_SIZE;
}
}
/** Construct a new output stream for creating a file. */
protected DFSOutputStream(DFSClient dfsClient, String src,
HdfsFileStatus stat, EnumSet<CreateFlag> flag, Progressable progress,
DataChecksum checksum, String[] favoredNodes, boolean createStreamer) {
this(dfsClient, src, flag, progress, stat, checksum);
this.shouldSyncBlock = flag.contains(CreateFlag.SYNC_BLOCK);
computePacketChunkSize(dfsClient.getConf().getWritePacketSize(),
bytesPerChecksum);
if (createStreamer) {
streamer = new DataStreamer(stat, null, dfsClient, src, progress,
checksum, cachingStrategy, byteArrayManager, favoredNodes,
addBlockFlags);
}
}
static DFSOutputStream newStreamForCreate(DFSClient dfsClient, String src,
FsPermission masked, EnumSet<CreateFlag> flag, boolean createParent,
short replication, long blockSize, Progressable progress,
DataChecksum checksum, String[] favoredNodes, String ecPolicyName,
String storagePolicy)
throws IOException {
try (TraceScope ignored =
dfsClient.newPathTraceScope("newStreamForCreate", src)) {
HdfsFileStatus stat = null;
// Retry the create if we get a RetryStartFileException up to a maximum
// number of times
boolean shouldRetry = true;
int retryCount = CREATE_RETRY_COUNT;
while (shouldRetry) {
shouldRetry = false;
try {
stat = dfsClient.namenode.create(src, masked, dfsClient.clientName,
new EnumSetWritable<>(flag), createParent, replication,
blockSize, SUPPORTED_CRYPTO_VERSIONS, ecPolicyName,
storagePolicy);
break;
} catch (RemoteException re) {
IOException e = re.unwrapRemoteException(
AccessControlException.class,
DSQuotaExceededException.class,
QuotaByStorageTypeExceededException.class,
FileAlreadyExistsException.class,
FileNotFoundException.class,
ParentNotDirectoryException.class,
NSQuotaExceededException.class,
RetryStartFileException.class,
SafeModeException.class,
UnresolvedPathException.class,
SnapshotAccessControlException.class,
UnknownCryptoProtocolVersionException.class);
if (e instanceof RetryStartFileException) {
if (retryCount > 0) {
shouldRetry = true;
retryCount--;
} else {
throw new IOException("Too many retries because of encryption" +
" zone operations", e);
}
} else {
throw e;
}
}
}
Preconditions.checkNotNull(stat, "HdfsFileStatus should not be null!");
final DFSOutputStream out;
if(stat.getErasureCodingPolicy() != null) {
out = new DFSStripedOutputStream(dfsClient, src, stat,
flag, progress, checksum, favoredNodes);
} else {
out = new DFSOutputStream(dfsClient, src, stat,
flag, progress, checksum, favoredNodes, true);
}
out.start();
return out;
}
}
/** Construct a new output stream for append. */
private DFSOutputStream(DFSClient dfsClient, String src,
EnumSet<CreateFlag> flags, Progressable progress, LocatedBlock lastBlock,
HdfsFileStatus stat, DataChecksum checksum, String[] favoredNodes)
throws IOException {
this(dfsClient, src, flags, progress, stat, checksum);
initialFileSize = stat.getLen(); // length of file when opened
this.shouldSyncBlock = flags.contains(CreateFlag.SYNC_BLOCK);
boolean toNewBlock = flags.contains(CreateFlag.NEW_BLOCK);
this.fileEncryptionInfo = stat.getFileEncryptionInfo();
// The last partial block of the file has to be filled.
if (!toNewBlock && lastBlock != null) {
// indicate that we are appending to an existing block
streamer = new DataStreamer(lastBlock, stat, dfsClient, src, progress,
checksum, cachingStrategy, byteArrayManager);
getStreamer().setBytesCurBlock(lastBlock.getBlockSize());
adjustPacketChunkSize(stat);
getStreamer().setPipelineInConstruction(lastBlock);
} else {
computePacketChunkSize(dfsClient.getConf().getWritePacketSize(),
bytesPerChecksum);
streamer = new DataStreamer(stat,
lastBlock != null ? lastBlock.getBlock() : null, dfsClient, src,
progress, checksum, cachingStrategy, byteArrayManager, favoredNodes,
addBlockFlags);
}
}
private void adjustPacketChunkSize(HdfsFileStatus stat) throws IOException{
long usedInLastBlock = stat.getLen() % blockSize;
int freeInLastBlock = (int)(blockSize - usedInLastBlock);
// calculate the amount of free space in the pre-existing
// last crc chunk
int usedInCksum = (int)(stat.getLen() % bytesPerChecksum);
int freeInCksum = bytesPerChecksum - usedInCksum;
// if there is space in the last block, then we have to
// append to that block
if (freeInLastBlock == blockSize) {
throw new IOException("The last block for file " +
src + " is full.");
}
if (usedInCksum > 0 && freeInCksum > 0) {
// if there is space in the last partial chunk, then
// setup in such a way that the next packet will have only
// one chunk that fills up the partial chunk.
//
computePacketChunkSize(0, freeInCksum);
setChecksumBufSize(freeInCksum);
getStreamer().setAppendChunk(true);
} else {
// if the remaining space in the block is smaller than
// that expected size of of a packet, then create
// smaller size packet.
//
computePacketChunkSize(
Math.min(dfsClient.getConf().getWritePacketSize(), freeInLastBlock),
bytesPerChecksum);
}
}
static DFSOutputStream newStreamForAppend(DFSClient dfsClient, String src,
EnumSet<CreateFlag> flags, Progressable progress, LocatedBlock lastBlock,
HdfsFileStatus stat, DataChecksum checksum, String[] favoredNodes)
throws IOException {
try (TraceScope ignored =
dfsClient.newPathTraceScope("newStreamForAppend", src)) {
DFSOutputStream out;
if (stat.isErasureCoded()) {
out = new DFSStripedOutputStream(dfsClient, src, flags, progress,
lastBlock, stat, checksum, favoredNodes);
} else {
out = new DFSOutputStream(dfsClient, src, flags, progress, lastBlock,
stat, checksum, favoredNodes);
}
out.start();
return out;
}
}
protected void computePacketChunkSize(int psize, int csize) {
final int bodySize = psize - PacketHeader.PKT_MAX_HEADER_LEN;
final int chunkSize = csize + getChecksumSize();
chunksPerPacket = Math.max(bodySize/chunkSize, 1);
packetSize = chunkSize*chunksPerPacket;
DFSClient.LOG.debug("computePacketChunkSize: src={}, chunkSize={}, "
+ "chunksPerPacket={}, packetSize={}",
src, chunkSize, chunksPerPacket, packetSize);
}
protected TraceScope createWriteTraceScope() {
return dfsClient.newPathTraceScope("DFSOutputStream#write", src);
}
// @see FSOutputSummer#writeChunk()
@Override
protected synchronized void writeChunk(byte[] b, int offset, int len,
byte[] checksum, int ckoff, int cklen) throws IOException {
writeChunkPrepare(len, ckoff, cklen);
currentPacket.writeChecksum(checksum, ckoff, cklen);
currentPacket.writeData(b, offset, len);
currentPacket.incNumChunks();
getStreamer().incBytesCurBlock(len);
// If packet is full, enqueue it for transmission
if (currentPacket.getNumChunks() == currentPacket.getMaxChunks() ||
getStreamer().getBytesCurBlock() == blockSize) {
enqueueCurrentPacketFull();
}
}
/* write the data chunk in <code>buffer</code> staring at
* <code>buffer.position</code> with
* a length of <code>len > 0</code>, and its checksum
*/
protected synchronized void writeChunk(ByteBuffer buffer, int len,
byte[] checksum, int ckoff, int cklen) throws IOException {
writeChunkPrepare(len, ckoff, cklen);
currentPacket.writeChecksum(checksum, ckoff, cklen);
currentPacket.writeData(buffer, len);
currentPacket.incNumChunks();
getStreamer().incBytesCurBlock(len);
// If packet is full, enqueue it for transmission
if (currentPacket.getNumChunks() == currentPacket.getMaxChunks() ||
getStreamer().getBytesCurBlock() == blockSize) {
enqueueCurrentPacketFull();
}
}
private synchronized void writeChunkPrepare(int buflen,
int ckoff, int cklen) throws IOException {
dfsClient.checkOpen();
checkClosed();
if (buflen > bytesPerChecksum) {
throw new IOException("writeChunk() buffer size is " + buflen +
" is larger than supported bytesPerChecksum " +
bytesPerChecksum);
}
if (cklen != 0 && cklen != getChecksumSize()) {
throw new IOException("writeChunk() checksum size is supposed to be " +
getChecksumSize() + " but found to be " + cklen);
}
if (currentPacket == null) {
currentPacket = createPacket(packetSize, chunksPerPacket, getStreamer()
.getBytesCurBlock(), getStreamer().getAndIncCurrentSeqno(), false);
DFSClient.LOG.debug("WriteChunk allocating new packet seqno={},"
+ " src={}, packetSize={}, chunksPerPacket={}, bytesCurBlock={},"
+ " output stream={}",
currentPacket.getSeqno(), src, packetSize, chunksPerPacket,
getStreamer().getBytesCurBlock(), this);
}
}
void enqueueCurrentPacket() throws IOException {
getStreamer().waitAndQueuePacket(currentPacket);
currentPacket = null;
}
synchronized void enqueueCurrentPacketFull() throws IOException {
LOG.debug("enqueue full {}, src={}, bytesCurBlock={}, blockSize={},"
+ " appendChunk={}, {}", currentPacket, src, getStreamer()
.getBytesCurBlock(), blockSize, getStreamer().getAppendChunk(),
getStreamer());
enqueueCurrentPacket();
adjustChunkBoundary();
endBlock();
}
/** create an empty packet to mark the end of the block. */
void setCurrentPacketToEmpty() throws InterruptedIOException {
currentPacket = createPacket(0, 0, getStreamer().getBytesCurBlock(),
getStreamer().getAndIncCurrentSeqno(), true);
currentPacket.setSyncBlock(shouldSyncBlock);
}
/**
* If the reopened file did not end at chunk boundary and the above
* write filled up its partial chunk. Tell the summer to generate full
* crc chunks from now on.
*/
protected void adjustChunkBoundary() {
if (getStreamer().getAppendChunk() &&
getStreamer().getBytesCurBlock() % bytesPerChecksum == 0) {
getStreamer().setAppendChunk(false);
resetChecksumBufSize();
}
if (!getStreamer().getAppendChunk()) {
final int psize = (int) Math
.min(blockSize - getStreamer().getBytesCurBlock(), writePacketSize);
computePacketChunkSize(psize, bytesPerChecksum);
}
}
/**
* Used in test only.
*/
@VisibleForTesting
void setAppendChunk(final boolean appendChunk) {
getStreamer().setAppendChunk(appendChunk);
}
/**
* Used in test only.
*/
@VisibleForTesting
void setBytesCurBlock(final long bytesCurBlock) {
getStreamer().setBytesCurBlock(bytesCurBlock);
}
/**
* if encountering a block boundary, send an empty packet to
* indicate the end of block and reset bytesCurBlock.
*
* @throws IOException
*/
void endBlock() throws IOException {
if (getStreamer().getBytesCurBlock() == blockSize) {
setCurrentPacketToEmpty();
enqueueCurrentPacket();
getStreamer().setBytesCurBlock(0);
lastFlushOffset = 0;
}
}
@Override
public boolean hasCapability(String capability) {
return StoreImplementationUtils.isProbeForSyncable(capability);
}
/**
* Flushes out to all replicas of the block. The data is in the buffers
* of the DNs but not necessarily in the DN's OS buffers.
*
* It is a synchronous operation. When it returns,
* it guarantees that flushed data become visible to new readers.
* It is not guaranteed that data has been flushed to
* persistent store on the datanode.
* Block allocations are persisted on namenode.
*/
@Override
public void hflush() throws IOException {
try (TraceScope ignored = dfsClient.newPathTraceScope("hflush", src)) {
flushOrSync(false, EnumSet.noneOf(SyncFlag.class));
}
}
@Override
public void hsync() throws IOException {
try (TraceScope ignored = dfsClient.newPathTraceScope("hsync", src)) {
flushOrSync(true, EnumSet.noneOf(SyncFlag.class));
}
}
/**
* The expected semantics is all data have flushed out to all replicas
* and all replicas have done posix fsync equivalent - ie the OS has
* flushed it to the disk device (but the disk may have it in its cache).
*
* Note that only the current block is flushed to the disk device.
* To guarantee durable sync across block boundaries the stream should
* be created with {@link CreateFlag#SYNC_BLOCK}.
*
* @param syncFlags
* Indicate the semantic of the sync. Currently used to specify
* whether or not to update the block length in NameNode.
*/
public void hsync(EnumSet<SyncFlag> syncFlags) throws IOException {
try (TraceScope ignored = dfsClient.newPathTraceScope("hsync", src)) {
flushOrSync(true, syncFlags);
}
}
/**
* Flush/Sync buffered data to DataNodes.
*
* @param isSync
* Whether or not to require all replicas to flush data to the disk
* device
* @param syncFlags
* Indicate extra detailed semantic of the flush/sync. Currently
* mainly used to specify whether or not to update the file length in
* the NameNode
* @throws IOException
*/
private void flushOrSync(boolean isSync, EnumSet<SyncFlag> syncFlags)
throws IOException {
dfsClient.checkOpen();
checkClosed();
try {
long toWaitFor;
long lastBlockLength = -1L;
boolean updateLength = syncFlags.contains(SyncFlag.UPDATE_LENGTH);
boolean endBlock = syncFlags.contains(SyncFlag.END_BLOCK);
synchronized (this) {
// flush checksum buffer, but keep checksum buffer intact if we do not
// need to end the current block
int numKept = flushBuffer(!endBlock, true);
// bytesCurBlock potentially incremented if there was buffered data
DFSClient.LOG.debug("DFSClient flush(): bytesCurBlock={}, "
+ "lastFlushOffset={}, createNewBlock={}",
getStreamer().getBytesCurBlock(), lastFlushOffset, endBlock);
// Flush only if we haven't already flushed till this offset.
if (lastFlushOffset != getStreamer().getBytesCurBlock()) {
assert getStreamer().getBytesCurBlock() > lastFlushOffset;
// record the valid offset of this flush
lastFlushOffset = getStreamer().getBytesCurBlock();
if (isSync && currentPacket == null && !endBlock) {
// Nothing to send right now,
// but sync was requested.
// Send an empty packet if we do not end the block right now
currentPacket = createPacket(packetSize, chunksPerPacket,
getStreamer().getBytesCurBlock(), getStreamer()
.getAndIncCurrentSeqno(), false);
}
} else {
if (isSync && getStreamer().getBytesCurBlock() > 0 && !endBlock) {
// Nothing to send right now,
// and the block was partially written,
// and sync was requested.
// So send an empty sync packet if we do not end the block right
// now
currentPacket = createPacket(packetSize, chunksPerPacket,
getStreamer().getBytesCurBlock(), getStreamer()
.getAndIncCurrentSeqno(), false);
} else if (currentPacket != null) {
// just discard the current packet since it is already been sent.
currentPacket.releaseBuffer(byteArrayManager);
currentPacket = null;
}
}
if (currentPacket != null) {
currentPacket.setSyncBlock(isSync);
enqueueCurrentPacket();
}
if (endBlock && getStreamer().getBytesCurBlock() > 0) {
// Need to end the current block, thus send an empty packet to
// indicate this is the end of the block and reset bytesCurBlock
currentPacket = createPacket(0, 0, getStreamer().getBytesCurBlock(),
getStreamer().getAndIncCurrentSeqno(), true);
currentPacket.setSyncBlock(shouldSyncBlock || isSync);
enqueueCurrentPacket();
getStreamer().setBytesCurBlock(0);
lastFlushOffset = 0;
} else {
// Restore state of stream. Record the last flush offset
// of the last full chunk that was flushed.
getStreamer().setBytesCurBlock(
getStreamer().getBytesCurBlock() - numKept);
}
toWaitFor = getStreamer().getLastQueuedSeqno();
} // end synchronized
getStreamer().waitForAckedSeqno(toWaitFor);
// update the block length first time irrespective of flag
if (updateLength || getStreamer().getPersistBlocks().get()) {
synchronized (this) {
if (!getStreamer().streamerClosed()
&& getStreamer().getBlock() != null) {
lastBlockLength = getStreamer().getBlock().getNumBytes();
}
}
}
// If 1) any new blocks were allocated since the last flush, or 2) to
// update length in NN is required, then persist block locations on
// namenode.
if (getStreamer().getPersistBlocks().getAndSet(false) || updateLength) {
try {
dfsClient.namenode.fsync(src, fileId, dfsClient.clientName,
lastBlockLength);
} catch (IOException ioe) {
DFSClient.LOG.warn("Unable to persist blocks in hflush for " + src,
ioe);
// If we got an error here, it might be because some other thread
// called close before our hflush completed. In that case, we should
// throw an exception that the stream is closed.
checkClosed();
// If we aren't closed but failed to sync, we should expose that to
// the caller.
throw ioe;
}
}
synchronized(this) {
if (!getStreamer().streamerClosed()) {
getStreamer().setHflush();
}
}
} catch (InterruptedIOException interrupt) {
// This kind of error doesn't mean that the stream itself is broken - just
// the flushing thread got interrupted. So, we shouldn't close down the
// writer, but instead just propagate the error
throw interrupt;
} catch (IOException e) {
DFSClient.LOG.warn("Error while syncing", e);
synchronized (this) {
if (!isClosed()) {
getStreamer().getLastException().set(e);
closeThreads(true);
}
}
throw e;
}
}
/**
* @deprecated use {@link HdfsDataOutputStream#getCurrentBlockReplication()}.
*/
@Deprecated
public synchronized int getNumCurrentReplicas() throws IOException {
return getCurrentBlockReplication();
}
/**
* Note that this is not a public API;
* use {@link HdfsDataOutputStream#getCurrentBlockReplication()} instead.
*
* @return the number of valid replicas of the current block
*/
public synchronized int getCurrentBlockReplication() throws IOException {
dfsClient.checkOpen();
checkClosed();
if (getStreamer().streamerClosed()) {
return blockReplication; // no pipeline, return repl factor of file
}
DatanodeInfo[] currentNodes = getStreamer().getNodes();
if (currentNodes == null) {
return blockReplication; // no pipeline, return repl factor of file
}
return currentNodes.length;
}
/**
* Waits till all existing data is flushed and confirmations
* received from datanodes.
*/
protected void flushInternal() throws IOException {
long toWaitFor = flushInternalWithoutWaitingAck();
getStreamer().waitForAckedSeqno(toWaitFor);
}
protected synchronized void start() {
getStreamer().start();
}
/**
* Aborts this output stream and releases any system
* resources associated with this stream.
*/
void abort() throws IOException {
final MultipleIOException.Builder b = new MultipleIOException.Builder();
synchronized (this) {
if (isClosed()) {
return;
}
getStreamer().getLastException().set(
new IOException("Lease timeout of "
+ (dfsClient.getConf().getHdfsTimeout() / 1000)
+ " seconds expired."));
try {
closeThreads(true);
} catch (IOException e) {
b.add(e);
}
}
final IOException ioe = b.build();
if (ioe != null) {
throw ioe;
}
}
boolean isClosed() {
return closed || getStreamer().streamerClosed();
}
void setClosed() {
closed = true;
dfsClient.endFileLease(getUniqKey());
getStreamer().release();
}
// shutdown datastreamer and responseprocessor threads.
// interrupt datastreamer if force is true
protected void closeThreads(boolean force) throws IOException {
try {
getStreamer().close(force);
getStreamer().join();
getStreamer().closeSocket();
} catch (InterruptedException e) {
throw new IOException("Failed to shutdown streamer");
} finally {
getStreamer().setSocketToNull();
setClosed();
}
}
/**
* Closes this output stream and releases any system
* resources associated with this stream.
*/
@Override
public void close() throws IOException {
final MultipleIOException.Builder b = new MultipleIOException.Builder();
synchronized (this) {
try (TraceScope ignored = dfsClient.newPathTraceScope(
"DFSOutputStream#close", src)) {
closeImpl();
} catch (IOException e) {
b.add(e);
}
}
final IOException ioe = b.build();
if (ioe != null) {
throw ioe;
}
}
protected synchronized void closeImpl() throws IOException {
boolean recoverLeaseOnCloseException = dfsClient.getConfiguration()
.getBoolean(RECOVER_LEASE_ON_CLOSE_EXCEPTION_KEY,
RECOVER_LEASE_ON_CLOSE_EXCEPTION_DEFAULT);
if (isClosed()) {
if (!leaseRecovered) {
recoverLease(recoverLeaseOnCloseException);
}
LOG.debug("Closing an already closed stream. [Stream:{}, streamer:{}]",
closed, getStreamer().streamerClosed());
try {
getStreamer().getLastException().check(true);
} catch (IOException ioe) {
cleanupAndRethrowIOException(ioe);
} finally {
if (!closed) {
// If stream is not closed but streamer closed, clean up the stream.
// Most importantly, end the file lease.
closeThreads(true);
}
}
return;
}
try {
flushBuffer(); // flush from all upper layers
if (currentPacket != null) {
enqueueCurrentPacket();
}
if (getStreamer().getBytesCurBlock() != 0) {
setCurrentPacketToEmpty();
}
try {
flushInternal(); // flush all data to Datanodes
} catch (IOException ioe) {
cleanupAndRethrowIOException(ioe);
}
completeFile();
} catch (ClosedChannelException ignored) {
} catch (IOException ioe) {
recoverLease(recoverLeaseOnCloseException);
throw ioe;
} finally {
// Failures may happen when flushing data.
// Streamers may keep waiting for the new block information.
// Thus need to force closing these threads.
// Don't need to call setClosed() because closeThreads(true)
// calls setClosed() in the finally block.
closeThreads(true);
}
}
/**
* If recoverLeaseOnCloseException is true and an exception occurs when
* closing a file, recover lease.
*/
protected void recoverLease(boolean recoverLeaseOnCloseException) {
if (recoverLeaseOnCloseException) {
try {
dfsClient.endFileLease(getUniqKey());
dfsClient.recoverLease(src);
leaseRecovered = true;
} catch (Exception e) {
LOG.warn("Fail to recover lease for {}", src, e);
}
}
}
void completeFile() throws IOException {
// get last block before destroying the streamer
ExtendedBlock lastBlock = getStreamer().getBlock();
try (TraceScope ignored = dfsClient.getTracer()
.newScope("DFSOutputStream#completeFile")) {
completeFile(lastBlock);
}
}
/**
* Determines whether an IOException thrown needs extra cleanup on the stream.
* Space quota exceptions will be thrown when getting new blocks, so the
* open HDFS file need to be closed.
*
* @param ioe the IOException
* @return whether the stream needs cleanup for the given IOException
*/
private boolean exceptionNeedsCleanup(IOException ioe) {
return ioe instanceof DSQuotaExceededException
|| ioe instanceof QuotaByStorageTypeExceededException;
}
private void cleanupAndRethrowIOException(IOException ioe)
throws IOException {
if (exceptionNeedsCleanup(ioe)) {
final MultipleIOException.Builder b = new MultipleIOException.Builder();
b.add(ioe);
try {
completeFile();
} catch (IOException e) {
b.add(e);
throw b.build();
}
}
throw ioe;
}
// should be called holding (this) lock since setTestFilename() may
// be called during unit tests
protected void completeFile(ExtendedBlock last) throws IOException {
long localstart = Time.monotonicNow();
final DfsClientConf conf = dfsClient.getConf();
long sleeptime = conf.getBlockWriteLocateFollowingInitialDelayMs();
long maxSleepTime = conf.getBlockWriteLocateFollowingMaxDelayMs();
boolean fileComplete = false;
int retries = conf.getNumBlockWriteLocateFollowingRetry();
while (!fileComplete) {
fileComplete =
dfsClient.namenode.complete(src, dfsClient.clientName, last, fileId);
if (!fileComplete) {
final int hdfsTimeout = conf.getHdfsTimeout();
if (!dfsClient.clientRunning
|| (hdfsTimeout > 0
&& localstart + hdfsTimeout < Time.monotonicNow())) {
String msg = "Unable to close file because dfsclient " +
" was unable to contact the HDFS servers. clientRunning " +
dfsClient.clientRunning + " hdfsTimeout " + hdfsTimeout;
DFSClient.LOG.info(msg);
throw new IOException(msg);
}
try (TraceScope scope = dfsClient.getTracer()
.newScope("DFSOutputStream#completeFile: Retry")) {
scope.addKVAnnotation("retries left", retries);
scope.addKVAnnotation("sleeptime (sleeping for)", sleeptime);
if (retries == 0) {
throw new IOException("Unable to close file because the last block "
+ last + " does not have enough number of replicas.");
}
retries--;
Thread.sleep(sleeptime);
sleeptime = calculateDelayForNextRetry(sleeptime, maxSleepTime);
if (Time.monotonicNow() - localstart > 5000) {
DFSClient.LOG.info("Could not complete " + src + " retrying...");
}
} catch (InterruptedException ie) {
DFSClient.LOG.warn("Caught exception ", ie);
}
}
}
}
@VisibleForTesting
public void setArtificialSlowdown(long period) {
getStreamer().setArtificialSlowdown(period);
}
@VisibleForTesting
public synchronized void setChunksPerPacket(int value) {
chunksPerPacket = Math.min(chunksPerPacket, value);
packetSize = (bytesPerChecksum + getChecksumSize()) * chunksPerPacket;
}
/**
* Returns the size of a file as it was when this stream was opened
*/
public long getInitialLen() {
return initialFileSize;
}
protected EnumSet<AddBlockFlag> getAddBlockFlags() {
return addBlockFlags;
}
/**
* @return the FileEncryptionInfo for this stream, or null if not encrypted.
*/
public FileEncryptionInfo getFileEncryptionInfo() {
return fileEncryptionInfo;
}
/**
* Returns the access token currently used by streamer, for testing only
*/
synchronized Token<BlockTokenIdentifier> getBlockToken() {
return getStreamer().getBlockToken();
}
protected long flushInternalWithoutWaitingAck() throws IOException {
long toWaitFor;
synchronized (this) {
dfsClient.checkOpen();
checkClosed();
//
// If there is data in the current buffer, send it across
//
getStreamer().queuePacket(currentPacket);
currentPacket = null;
toWaitFor = getStreamer().getLastQueuedSeqno();
}
return toWaitFor;
}
@Override
public void setDropBehind(Boolean dropBehind) throws IOException {
CachingStrategy prevStrategy, nextStrategy;
// CachingStrategy is immutable. So build a new CachingStrategy with the
// modifications we want, and compare-and-swap it in.
do {
prevStrategy = this.cachingStrategy.get();
nextStrategy = new CachingStrategy.Builder(prevStrategy).
setDropBehind(dropBehind).build();
} while (!this.cachingStrategy.compareAndSet(prevStrategy, nextStrategy));
}
@VisibleForTesting
ExtendedBlock getBlock() {
return getStreamer().getBlock();
}
@VisibleForTesting
public long getFileId() {
return fileId;
}
@VisibleForTesting
public String getNamespace() {
return namespace;
}
@VisibleForTesting
public String getUniqKey() {
return this.uniqKey;
}
/**
* Return the source of stream.
*/
String getSrc() {
return src;
}
/**
* Returns the data streamer object.
*/
protected DataStreamer getStreamer() {
return streamer;
}
@Override
public String toString() {
return getClass().getSimpleName() + ":" + streamer;
}
@VisibleForTesting
boolean isLeaseRecovered() {
return leaseRecovered;
}
static LocatedBlock addBlock(DatanodeInfo[] excludedNodes,
DFSClient dfsClient, String src, ExtendedBlock prevBlock, long fileId,
String[] favoredNodes, EnumSet<AddBlockFlag> allocFlags)
throws IOException {
final DfsClientConf conf = dfsClient.getConf();
int retries = conf.getNumBlockWriteLocateFollowingRetry();
long sleeptime = conf.getBlockWriteLocateFollowingInitialDelayMs();
long maxSleepTime = conf.getBlockWriteLocateFollowingMaxDelayMs();
long localstart = Time.monotonicNow();
while (true) {
try {
return dfsClient.namenode.addBlock(src, dfsClient.clientName, prevBlock,
excludedNodes, fileId, favoredNodes, allocFlags);
} catch (RemoteException e) {
IOException ue = e.unwrapRemoteException(FileNotFoundException.class,
AccessControlException.class,
NSQuotaExceededException.class,
DSQuotaExceededException.class,
QuotaByStorageTypeExceededException.class,
UnresolvedPathException.class);
if (ue != e) {
throw ue; // no need to retry these exceptions
}
if (NotReplicatedYetException.class.getName()
.equals(e.getClassName())) {
if (retries == 0) {
throw e;
} else {
--retries;
LOG.info("Exception while adding a block", e);
long elapsed = Time.monotonicNow() - localstart;
if (elapsed > 5000) {
LOG.info("Waiting for replication for " + (elapsed / 1000)
+ " seconds");
}
try {
LOG.warn("NotReplicatedYetException sleeping " + src
+ " retries left " + retries);
Thread.sleep(sleeptime);
sleeptime = calculateDelayForNextRetry(sleeptime, maxSleepTime);
} catch (InterruptedException ie) {
LOG.warn("Caught exception", ie);
}
}
} else {
throw e;
}
}
}
}
/**
* Calculates the delay for the next retry.
*
* The delay is increased exponentially until the maximum delay is reached.
*
* @param previousDelay delay for the previous retry
* @param maxDelay maximum delay
* @return the minimum of the double of the previous delay
* and the maximum delay
*/
private static long calculateDelayForNextRetry(long previousDelay,
long maxDelay) {
return Math.min(previousDelay * 2, maxDelay);
}
}
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