/**
* 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 org.apache.hadoop.io.*;
import org.apache.hadoop.io.retry.RetryPolicies;
import org.apache.hadoop.io.retry.RetryPolicy;
import org.apache.hadoop.io.retry.RetryProxy;
import org.apache.hadoop.fs.*;
import org.apache.hadoop.fs.permission.FsPermission;
import org.apache.hadoop.ipc.*;
import org.apache.hadoop.net.NetUtils;
import org.apache.hadoop.net.NodeBase;
import org.apache.hadoop.conf.*;
import org.apache.hadoop.hdfs.DistributedFileSystem.DiskStatus;
import org.apache.hadoop.hdfs.metrics.DFSClientMetrics;
import org.apache.hadoop.hdfs.protocol.*;
import org.apache.hadoop.hdfs.server.common.HdfsConstants;
import org.apache.hadoop.hdfs.server.common.UpgradeStatusReport;
import org.apache.hadoop.hdfs.server.datanode.DataNode;
import org.apache.hadoop.hdfs.server.namenode.NameNode;
import org.apache.hadoop.hdfs.server.namenode.NotReplicatedYetException;
import org.apache.hadoop.security.AccessControlException;
import org.apache.hadoop.security.UnixUserGroupInformation;
import org.apache.hadoop.util.*;
import org.apache.hadoop.ipc.Client;
import org.apache.commons.logging.*;
import java.io.*;
import java.net.*;
import java.util.*;
import java.util.zip.CRC32;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.ConcurrentHashMap;
import java.nio.BufferOverflowException;
import java.nio.ByteBuffer;
import javax.net.SocketFactory;
import javax.security.auth.login.LoginException;
/********************************************************
* DFSClient can connect to a Hadoop Filesystem and
* perform basic file tasks. It uses the ClientProtocol
* to communicate with a NameNode daemon, and connects
* directly to DataNodes to read/write block data.
*
* Hadoop DFS users should obtain an instance of
* DistributedFileSystem, which uses DFSClient to handle
* filesystem tasks.
*
********************************************************/
public class DFSClient implements FSConstants, java.io.Closeable {
public static final Log LOG = LogFactory.getLog(DFSClient.class);
public static final int MAX_BLOCK_ACQUIRE_FAILURES = 3;
private static final int TCP_WINDOW_SIZE = 128 * 1024; // 128 KB
public ClientProtocol namenode;
private ClientProtocol rpcNamenode;
// Namenode proxy that supports method-based compatibility
private ProtocolProxy<ClientProtocol> namenodeProtocolProxy = null;
final UnixUserGroupInformation ugi;
volatile boolean clientRunning = true;
static Random r = new Random();
final String clientName;
final LeaseChecker leasechecker = new LeaseChecker();
private Configuration conf;
private long defaultBlockSize;
private short defaultReplication;
private SocketFactory socketFactory;
private int socketTimeout;
private int datanodeWriteTimeout;
private int timeoutValue; // read timeout for the socket
final int writePacketSize;
private final FileSystem.Statistics stats;
private int maxBlockAcquireFailures;
private final int hdfsTimeout; // timeout value for a DFS operation.
private long namenodeVersion = ClientProtocol.versionID;
private DFSClientMetrics metrics = new DFSClientMetrics();
private Integer dataTransferVersion = -1;
private boolean shortCircuitLocalReads = false;
private final InetAddress localHost;
/**
* The locking hierarchy is to first acquire lock on DFSClient object, followed by
* lock on leasechecker, followed by lock on an individual DFSOutputStream.
*/
public static ClientProtocol createNamenode(Configuration conf) throws IOException {
return createNamenode(NameNode.getAddress(conf), conf);
}
public static ClientProtocol createNamenode( InetSocketAddress nameNodeAddr,
Configuration conf) throws IOException {
try {
return createNamenode(createRPCNamenode(nameNodeAddr, conf,
UnixUserGroupInformation.login(conf, true)).getProxy());
} catch (LoginException e) {
throw (IOException)(new IOException().initCause(e));
}
}
/**
* Create a NameNode proxy for the client if the client and NameNode
* are compatible
*
* @param nameNodeAddr NameNode address
* @param conf configuration
* @param ugi ticket
* @return a NameNode proxy that's compatible with the client
*/
private void createRPCNamenodeIfCompatible(
InetSocketAddress nameNodeAddr,
Configuration conf,
UnixUserGroupInformation ugi) throws IOException {
try {
this.namenodeProtocolProxy = createRPCNamenode(nameNodeAddr, conf, ugi);
this.rpcNamenode = namenodeProtocolProxy.getProxy();
} catch (RPC.VersionMismatch e) {
long clientVersion = e.getClientVersion();
namenodeVersion = e.getServerVersion();
if (clientVersion > namenodeVersion &&
!ProtocolCompatible.isCompatibleClientProtocol(
clientVersion, namenodeVersion)) {
throw new RPC.VersionIncompatible(
ClientProtocol.class.getName(), clientVersion, namenodeVersion);
}
this.rpcNamenode = (ClientProtocol)e.getProxy();
}
}
private static ProtocolProxy<ClientProtocol> createRPCNamenode(InetSocketAddress nameNodeAddr,
Configuration conf, UnixUserGroupInformation ugi)
throws IOException {
return RPC.getProtocolProxy(ClientProtocol.class,
ClientProtocol.versionID, nameNodeAddr, ugi, conf,
NetUtils.getSocketFactory(conf, ClientProtocol.class));
}
private static ClientProtocol createNamenode(ClientProtocol rpcNamenode)
throws IOException {
RetryPolicy createPolicy = RetryPolicies.retryUpToMaximumCountWithFixedSleep(
5, LEASE_SOFTLIMIT_PERIOD, TimeUnit.MILLISECONDS);
Map<Class<? extends Exception>,RetryPolicy> remoteExceptionToPolicyMap =
new HashMap<Class<? extends Exception>, RetryPolicy>();
remoteExceptionToPolicyMap.put(AlreadyBeingCreatedException.class, createPolicy);
Map<Class<? extends Exception>,RetryPolicy> exceptionToPolicyMap =
new HashMap<Class<? extends Exception>, RetryPolicy>();
exceptionToPolicyMap.put(RemoteException.class,
RetryPolicies.retryByRemoteException(
RetryPolicies.TRY_ONCE_THEN_FAIL, remoteExceptionToPolicyMap));
RetryPolicy methodPolicy = RetryPolicies.retryByException(
RetryPolicies.TRY_ONCE_THEN_FAIL, exceptionToPolicyMap);
Map<String,RetryPolicy> methodNameToPolicyMap = new HashMap<String,RetryPolicy>();
methodNameToPolicyMap.put("create", methodPolicy);
return (ClientProtocol) RetryProxy.create(ClientProtocol.class,
rpcNamenode, methodNameToPolicyMap);
}
static ClientDatanodeProtocol createClientDatanodeProtocolProxy (
DatanodeID datanodeid, Configuration conf) throws IOException {
InetSocketAddress addr = NetUtils.createSocketAddr(
datanodeid.getHost() + ":" + datanodeid.getIpcPort());
if (ClientDatanodeProtocol.LOG.isDebugEnabled()) {
ClientDatanodeProtocol.LOG.info("ClientDatanodeProtocol addr=" + addr);
}
try {
return (ClientDatanodeProtocol)RPC.getProxy(ClientDatanodeProtocol.class,
ClientDatanodeProtocol.versionID, addr, conf);
} catch (RPC.VersionMismatch e) {
long clientVersion = e.getClientVersion();
long datanodeVersion = e.getServerVersion();
if (clientVersion > datanodeVersion &&
!ProtocolCompatible.isCompatibleClientDatanodeProtocol(clientVersion,
datanodeVersion)) {
throw new RPC.VersionIncompatible(ClientDatanodeProtocol.class.getName(),
clientVersion, datanodeVersion);
}
return (ClientDatanodeProtocol)e.getProxy();
}
}
/**
* Same as this(NameNode.getAddress(conf), conf);
* @see #DFSClient(InetSocketAddress, Configuration)
*/
public DFSClient(Configuration conf) throws IOException {
this(NameNode.getAddress(conf), conf);
}
/**
* Same as this(nameNodeAddr, conf, null);
* @see #DFSClient(InetSocketAddress, Configuration, org.apache.hadoop.fs.FileSystem.Statistics)
*/
public DFSClient(InetSocketAddress nameNodeAddr, Configuration conf
) throws IOException {
this(nameNodeAddr, conf, null);
}
/**
* Same as this(nameNodeAddr, null, conf, stats);
* @see #DFSClient(InetSocketAddress, ClientProtocol, Configuration, org.apache.hadoop.fs.FileSystem.Statistics)
*/
public DFSClient(InetSocketAddress nameNodeAddr, Configuration conf,
FileSystem.Statistics stats)
throws IOException {
this(nameNodeAddr, null, conf, stats);
}
/**
* Create a new DFSClient connected to the given nameNodeAddr or rpcNamenode.
* Exactly one of nameNodeAddr or rpcNamenode must be null.
*/
DFSClient(InetSocketAddress nameNodeAddr, ClientProtocol rpcNamenode,
Configuration conf, FileSystem.Statistics stats)
throws IOException {
this.conf = conf;
this.stats = stats;
this.socketTimeout = conf.getInt("dfs.socket.timeout",
HdfsConstants.READ_TIMEOUT);
this.timeoutValue = this.socketTimeout;
this.datanodeWriteTimeout = conf.getInt("dfs.datanode.socket.write.timeout",
HdfsConstants.WRITE_TIMEOUT);
this.socketFactory = NetUtils.getSocketFactory(conf, ClientProtocol.class);
// dfs.write.packet.size is an internal config variable
this.writePacketSize = conf.getInt("dfs.write.packet.size", 64*1024);
this.maxBlockAcquireFailures =
conf.getInt("dfs.client.max.block.acquire.failures",
MAX_BLOCK_ACQUIRE_FAILURES);
this.localHost = InetAddress.getLocalHost();
// The hdfsTimeout is currently the same as the ipc timeout
this.hdfsTimeout = Client.getTimeout(conf);
try {
this.ugi = UnixUserGroupInformation.login(conf, true);
} catch (LoginException e) {
throw (IOException)(new IOException().initCause(e));
}
String taskId = conf.get("mapred.task.id");
if (taskId != null) {
this.clientName = "DFSClient_" + taskId + "_" + r.nextInt()
+ "_" + Thread.currentThread().getId();
} else {
this.clientName = "DFSClient_" + r.nextInt();
}
defaultBlockSize = conf.getLong("dfs.block.size", DEFAULT_BLOCK_SIZE);
defaultReplication = (short) conf.getInt("dfs.replication", 3);
if (nameNodeAddr != null && rpcNamenode == null) {
createRPCNamenodeIfCompatible(nameNodeAddr, conf, ugi);
this.namenode = createNamenode(this.rpcNamenode);
} else if (nameNodeAddr == null && rpcNamenode != null) {
//This case is used for testing.
this.namenode = this.rpcNamenode = rpcNamenode;
} else {
throw new IllegalArgumentException(
"Expecting exactly one of nameNodeAddr and rpcNamenode being null: "
+ "nameNodeAddr=" + nameNodeAddr + ", rpcNamenode=" + rpcNamenode);
}
// read directly from the block file if configured.
this.shortCircuitLocalReads = conf.getBoolean("dfs.read.shortcircuit", false);
}
private void checkOpen() throws IOException {
if (!clientRunning) {
IOException result = new IOException("Filesystem closed");
throw result;
}
}
//
// If the call stack does not have FsShell.delete(), then invoke
// FsShell.delete. This ensures that files always goes thru Trash.
// Returns 0 if the file is successfully deleted by this method,
// Returns -1 if the file is not being deleted by this method
// Returns 1 if this method tried deleting the file but failed.
//
private int deleteUsingTrash(String file, boolean recursive) throws IOException {
// The configuration parameter specifies the class name to match.
// Typically, this is set to org.apache.hadoop.fs.FsShell.delete
String className = conf.get("fs.shell.delete.classname");
if (className == null) {
className = "org.apache.hadoop.fs.FsShell.delete";
}
// find the stack trace of this thread
StringWriter str = new StringWriter();
PrintWriter pr = new PrintWriter(str);
try {
throw new Throwable();
} catch (Throwable t) {
t.printStackTrace(pr);
}
// if the specified class does not appear in the calling thread's
// stack trace, and if this file is not in "/tmp",
// then invoke FsShell.delete()
if (str.toString().indexOf(className) == -1 &&
file.indexOf("/tmp") != 0) {
String errmsg = "File " + file + " is being deleted only through" +
" Trash " + className +
" because all deletes must go through Trash.";
LOG.warn(errmsg);
FsShell fh = new FsShell(conf);
Path p = new Path(file);
fh.init();
try {
fh.delete(p, p.getFileSystem(conf), recursive, false);
return 0; // successful deletion
} catch (RemoteException rex) {
throw rex.unwrapRemoteException(AccessControlException.class);
} catch (AccessControlException ace) {
throw ace;
} catch (IOException e) {
return 1; // deletion unsuccessful
}
}
return -1; // deletion not attempted
}
/**
* Close the file system, abandoning all of the leases and files being
* created and close connections to the namenode.
*/
public synchronized void close() throws IOException {
if(clientRunning) {
leasechecker.close();
clientRunning = false;
try {
leasechecker.interruptAndJoin();
} catch (InterruptedException ie) {
}
// close connections to the namenode
RPC.stopProxy(rpcNamenode);
}
}
/**
* Get the default block size for this cluster
* @return the default block size in bytes
*/
public long getDefaultBlockSize() {
return defaultBlockSize;
}
public long getBlockSize(String f) throws IOException {
try {
return namenode.getPreferredBlockSize(f);
} catch (IOException ie) {
LOG.warn("Problem getting block size: " +
StringUtils.stringifyException(ie));
throw ie;
}
}
/**
* Report corrupt blocks that were discovered by the client.
*/
public void reportBadBlocks(LocatedBlock[] blocks) throws IOException {
namenode.reportBadBlocks(blocks);
}
public short getDefaultReplication() {
return defaultReplication;
}
/**
* @deprecated Use getBlockLocations instead
*
* Get hints about the location of the indicated block(s).
*
* getHints() returns a list of hostnames that store data for
* a specific file region. It returns a set of hostnames for
* every block within the indicated region.
*
* This function is very useful when writing code that considers
* data-placement when performing operations. For example, the
* MapReduce system tries to schedule tasks on the same machines
* as the data-block the task processes.
*/
@Deprecated
public String[][] getHints(String src, long start, long length)
throws IOException {
BlockLocation[] blkLocations = getBlockLocations(src, start, length);
if ((blkLocations == null) || (blkLocations.length == 0)) {
return new String[0][];
}
int blkCount = blkLocations.length;
String[][]hints = new String[blkCount][];
for (int i=0; i < blkCount ; i++) {
String[] hosts = blkLocations[i].getHosts();
hints[i] = new String[hosts.length];
hints[i] = hosts;
}
return hints;
}
private static LocatedBlocks callGetBlockLocations(ClientProtocol namenode,
String src, long start, long length) throws IOException {
try {
return namenode.getBlockLocations(src, start, length);
} catch(RemoteException re) {
throw re.unwrapRemoteException(AccessControlException.class,
FileNotFoundException.class);
}
}
/**
* Get block location info about file
*
* getBlockLocations() returns a list of hostnames that store
* data for a specific file region. It returns a set of hostnames
* for every block within the indicated region.
*
* This function is very useful when writing code that considers
* data-placement when performing operations. For example, the
* MapReduce system tries to schedule tasks on the same machines
* as the data-block the task processes.
*/
public BlockLocation[] getBlockLocations(String src, long start,
long length) throws IOException {
LocatedBlocks blocks = callGetBlockLocations(namenode, src, start, length);
return DFSUtil.locatedBlocks2Locations(blocks);
}
public DFSInputStream open(String src) throws IOException {
return open(src, conf.getInt("io.file.buffer.size", 4096), true, null);
}
/**
* Create an input stream that obtains a nodelist from the
* namenode, and then reads from all the right places. Creates
* inner subclass of InputStream that does the right out-of-band
* work.
*/
DFSInputStream open(String src, int buffersize, boolean verifyChecksum,
FileSystem.Statistics stats
) throws IOException {
checkOpen();
// Get block info from namenode
return new DFSInputStream(src, buffersize, verifyChecksum);
}
/**
* Create a new dfs file and return an output stream for writing into it.
*
* @param src stream name
* @param overwrite do not check for file existence if true
* @return output stream
* @throws IOException
*/
public OutputStream create(String src,
boolean overwrite
) throws IOException {
return create(src, overwrite, defaultReplication, defaultBlockSize, null);
}
/**
* Create a new dfs file and return an output stream for writing into it
* with write-progress reporting.
*
* @param src stream name
* @param overwrite do not check for file existence if true
* @return output stream
* @throws IOException
*/
public OutputStream create(String src,
boolean overwrite,
Progressable progress
) throws IOException {
return create(src, overwrite, defaultReplication, defaultBlockSize, null);
}
/**
* Create a new dfs file with the specified block replication
* and return an output stream for writing into the file.
*
* @param src stream name
* @param overwrite do not check for file existence if true
* @param replication block replication
* @return output stream
* @throws IOException
*/
public OutputStream create(String src,
boolean overwrite,
short replication,
long blockSize
) throws IOException {
return create(src, overwrite, replication, blockSize, null);
}
/**
* Create a new dfs file with the specified block replication
* with write-progress reporting and return an output stream for writing
* into the file.
*
* @param src stream name
* @param overwrite do not check for file existence if true
* @param replication block replication
* @return output stream
* @throws IOException
*/
public OutputStream create(String src,
boolean overwrite,
short replication,
long blockSize,
Progressable progress
) throws IOException {
return create(src, overwrite, replication, blockSize, progress,
conf.getInt("io.file.buffer.size", 4096));
}
/**
* Call
* {@link #create(String,FsPermission,boolean,short,long,Progressable,int)}
* with default permission.
* @see FsPermission#getDefault()
*/
public OutputStream create(String src,
boolean overwrite,
short replication,
long blockSize,
Progressable progress,
int buffersize
) throws IOException {
return create(src, FsPermission.getDefault(),
overwrite, replication, blockSize, progress, buffersize);
}
/**
* Create a new dfs file with the specified block replication
* with write-progress reporting and return an output stream for writing
* into the file.
*
* @param src stream name
* @param permission The permission of the directory being created.
* If permission == null, use {@link FsPermission#getDefault()}.
* @param overwrite do not check for file existence if true
* @param replication block replication
* @return output stream
* @throws IOException
* @see ClientProtocol#create(String, FsPermission, String, boolean, short, long)
*/
public OutputStream create(String src,
FsPermission permission,
boolean overwrite,
short replication,
long blockSize,
Progressable progress,
int buffersize
) throws IOException {
checkOpen();
if (permission == null) {
permission = FsPermission.getDefault();
}
FsPermission masked = permission.applyUMask(FsPermission.getUMask(conf));
LOG.debug(src + ": masked=" + masked);
OutputStream result = new DFSOutputStream(src, masked,
overwrite, replication, blockSize, progress, buffersize,
conf.getInt("io.bytes.per.checksum", 512));
leasechecker.put(src, result);
return result;
}
/**
* Append to an existing HDFS file.
*
* @param src file name
* @param buffersize buffer size
* @param progress for reporting write-progress
* @return an output stream for writing into the file
* @throws IOException
* @see ClientProtocol#append(String, String)
*/
OutputStream append(String src, int buffersize, Progressable progress
) throws IOException {
checkOpen();
FileStatus stat = null;
LocatedBlock lastBlock = null;
try {
stat = getFileInfo(src);
lastBlock = namenode.append(src, clientName);
} catch(RemoteException re) {
throw re.unwrapRemoteException(FileNotFoundException.class,
AccessControlException.class,
NSQuotaExceededException.class,
DSQuotaExceededException.class);
}
OutputStream result = new DFSOutputStream(src, buffersize, progress,
lastBlock, stat, conf.getInt("io.bytes.per.checksum", 512));
leasechecker.put(src, result);
return result;
}
/**
* Set replication for an existing file.
*
* @see ClientProtocol#setReplication(String, short)
* @param replication
* @throws IOException
* @return true is successful or false if file does not exist
*/
public boolean setReplication(String src,
short replication
) throws IOException {
try {
return namenode.setReplication(src, replication);
} catch(RemoteException re) {
throw re.unwrapRemoteException(AccessControlException.class,
NSQuotaExceededException.class,
DSQuotaExceededException.class);
}
}
/*
* Move blocks from src to trg and delete src
* See {@link ClientProtocol#concat(String, String [])}.
*/
public void concat(String trg, String [] srcs) throws IOException {
checkOpen();
try {
namenode.concat(trg, srcs);
} catch(RemoteException re) {
throw re.unwrapRemoteException(AccessControlException.class,
NSQuotaExceededException.class,
DSQuotaExceededException.class);
}
}
/**
* Rename file or directory.
* See {@link ClientProtocol#rename(String, String)}.
*/
public boolean rename(String src, String dst) throws IOException {
checkOpen();
try {
return namenode.rename(src, dst);
} catch(RemoteException re) {
throw re.unwrapRemoteException(AccessControlException.class,
NSQuotaExceededException.class,
DSQuotaExceededException.class);
}
}
/**
* Delete file or directory.
* See {@link ClientProtocol#delete(String)}.
*/
@Deprecated
public boolean delete(String src) throws IOException {
checkOpen();
int val = deleteUsingTrash(src, true); // allow deletion only from FsShell
if (val == 0) {
return true;
} else if (val == 1) {
return false;
}
return namenode.delete(src, true);
}
/**
* delete file or directory.
* delete contents of the directory if non empty and recursive
* set to true
*/
public boolean delete(String src, boolean recursive) throws IOException {
checkOpen();
int val = deleteUsingTrash(src, recursive); // allow deletion only from FsShell
if (val == 0) {
return true;
} else if (val == 1) {
return false;
}
try {
return namenode.delete(src, recursive);
} catch(RemoteException re) {
throw re.unwrapRemoteException(AccessControlException.class);
}
}
/** Implemented using getFileInfo(src)
*/
public boolean exists(String src) throws IOException {
checkOpen();
return getFileInfo(src) != null;
}
/** @deprecated Use getFileStatus() instead */
@Deprecated
public boolean isDirectory(String src) throws IOException {
FileStatus fs = getFileInfo(src);
if (fs != null)
return fs.isDir();
else
throw new FileNotFoundException("File does not exist: " + src);
}
/**
* Convert an HdfsFileStatus to a FileStatus
* @param stat an HdfsFileStatus
* @param src parent path in string representation
* @return a FileStatus object
*/
private static FileStatus toFileStatus(HdfsFileStatus stat, String src) {
if (stat == null) {
return null;
}
return new FileStatus(stat.getLen(), stat.isDir(), stat.getReplication(),
stat.getBlockSize(), stat.getModificationTime(),
stat.getAccessTime(),
stat.getPermission(), stat.getOwner(), stat.getGroup(),
stat.getFullPath(new Path(src))); // full path
}
/**
* Convert an HdfsFileStatus and its block locations to a LocatedFileStatus
* @param stat an HdfsFileStatus
* @param locs the file's block locations
* @param src parent path in string representation
* @return a FileStatus object
*/
private static LocatedFileStatus toLocatedFileStatus(
HdfsFileStatus stat, LocatedBlocks locs, String src) {
if (stat == null) {
return null;
}
return new LocatedFileStatus(stat.getLen(),
stat.isDir(), stat.getReplication(),
stat.getBlockSize(), stat.getModificationTime(),
stat.getAccessTime(),
stat.getPermission(), stat.getOwner(), stat.getGroup(),
stat.getFullPath(new Path(src)), // full path
DFSUtil.locatedBlocks2Locations(locs));
}
/**
* Get a listing of the indicated directory
*/
public FileStatus[] listPaths(String src) throws IOException {
checkOpen();
metrics.incLsCalls();
try {
if (namenodeProtocolProxy == null) {
return versionBasedListPath(src);
}
return methodBasedListPath(src);
} catch(RemoteException re) {
throw re.unwrapRemoteException(AccessControlException.class);
}
}
private FileStatus[] versionBasedListPath(String src) throws IOException {
if (namenodeVersion >= ClientProtocol.ITERATIVE_LISTING_VERSION) {
return iterativeListing(src);
} else if (namenodeVersion >= ClientProtocol.OPTIMIZE_FILE_STATUS_VERSION) {
HdfsFileStatus[] hdfsStats = namenode.getHdfsListing(src);
if (hdfsStats == null) {
return null;
}
FileStatus[] stats = new FileStatus[hdfsStats.length];
for (int i=0; i<stats.length; i++) {
stats[i] = toFileStatus(hdfsStats[i], src);
}
return stats;
} else {
return namenode.getListing(src);
}
}
private FileStatus[] methodBasedListPath(String src) throws IOException {
if (namenodeProtocolProxy.isMethodSupported(
"getPartialListing", String.class, byte[].class)) {
return iterativeListing(src);
} else if (namenodeProtocolProxy.isMethodSupported(
"getHdfsListing", String.class)) {
HdfsFileStatus[] hdfsStats = namenode.getHdfsListing(src);
if (hdfsStats == null) {
return null;
}
FileStatus[] stats = new FileStatus[hdfsStats.length];
for (int i=0; i<stats.length; i++) {
stats[i] = toFileStatus(hdfsStats[i], src);
}
return stats;
} else {
return namenode.getListing(src);
}
}
/**
* Get a partial listing of the indicated directory
*
* Recommend to use HdfsFileStatus.EMPTY_NAME as startAfter
* if the application wants to fetch a listing starting from
* the first entry in the directory
*
* @see ClientProtocol#getLocatedPartialListing(String, byte[])
*/
public RemoteIterator<LocatedFileStatus> listPathWithLocation(
final String src) throws IOException {
checkOpen();
try {
if (namenodeProtocolProxy == null) {
return versionBasedListPathWithLocation(src);
}
return methodBasedListPathWithLocation(src);
} catch(RemoteException re) {
throw re.unwrapRemoteException(AccessControlException.class);
}
}
/** List a directory with location based on version */
private RemoteIterator<LocatedFileStatus> versionBasedListPathWithLocation(
final String src) throws IOException {
if (namenodeVersion >= ClientProtocol.BULK_BLOCK_LOCATIONS_VERSION) {
return iteratorListing(src);
} else {
return arrayListing(src);
}
}
/** List a directory with location based on method */
private RemoteIterator<LocatedFileStatus> methodBasedListPathWithLocation(
final String src) throws IOException {
if (namenodeProtocolProxy.isMethodSupported(
"getLocatedPartialListing", String.class, byte[].class)) {
return iteratorListing(src);
} else {
return arrayListing(src);
}
}
/** create the iterator from an array of file status */
private RemoteIterator<LocatedFileStatus> arrayListing(final String src)
throws IOException {
return new RemoteIterator<LocatedFileStatus>() {
private FileStatus[] stats;
private int i = 0;
{ //initializer
stats = listPaths(src);
if (stats == null) {
throw new FileNotFoundException("File " + src + " does not exist.");
}
}
@Override
public boolean hasNext() throws IOException {
return i<stats.length;
}
@Override
public LocatedFileStatus next() throws IOException {
if (!hasNext()) {
throw new NoSuchElementException("No more entry in " + src);
}
FileStatus result = stats[i++];
BlockLocation[] locs = result.isDir() ? null :
getBlockLocations(
result.getPath().toUri().getPath(), 0, result.getLen());
return new LocatedFileStatus(result, locs);
}
};
}
/** create the iterator from the iterative listing with block locations */
private RemoteIterator<LocatedFileStatus> iteratorListing(final String src)
throws IOException {
return new RemoteIterator<LocatedFileStatus>() {
private LocatedDirectoryListing thisListing;
private int i;
{ // initializer
// fetch the first batch of entries in the directory
thisListing = namenode.getLocatedPartialListing(
src, HdfsFileStatus.EMPTY_NAME);
if (thisListing == null) { // the directory does not exist
throw new FileNotFoundException("File " + src + " does not exist.");
}
}
@Override
public boolean hasNext() throws IOException {
if (i>=thisListing.getPartialListing().length
&& thisListing.hasMore()) {
// current listing is exhausted & fetch a new listing
thisListing = namenode.getLocatedPartialListing(
src, thisListing.getLastName());
if (thisListing == null) {
throw new FileNotFoundException("File " + src + " does not exist.");
}
i = 0;
}
return i < thisListing.getPartialListing().length;
}
@Override
public LocatedFileStatus next() throws IOException {
if (!hasNext()) {
throw new java.util.NoSuchElementException("No more entry in " + src);
}
return toLocatedFileStatus(
thisListing.getPartialListing()[i],
thisListing.getBlockLocations()[i++], src);
}
};
}
/**
* List the given path iteratively if the directory is large
*
* @param src a path
* @return a listing of the path
* @throws IOException if any IO error is occurred
*/
private FileStatus[] iterativeListing(String src) throws IOException {
// fetch the first batch of entries in the directory
DirectoryListing thisListing = namenode.getPartialListing(
src, HdfsFileStatus.EMPTY_NAME);
if (thisListing == null) { // the directory does not exist
return null;
}
HdfsFileStatus[] partialListing = thisListing.getPartialListing();
if (!thisListing.hasMore()) { // got all entries of the directory
FileStatus[] stats = new FileStatus[partialListing.length];
for (int i = 0; i < partialListing.length; i++) {
stats[i] = toFileStatus(partialListing[i], src);
}
return stats;
}
// The directory size is too big that it needs to fetch more
// estimate the total number of entries in the directory
int totalNumEntries =
partialListing.length + thisListing.getRemainingEntries();
ArrayList<FileStatus> listing =
new ArrayList<FileStatus>(totalNumEntries);
// add the first batch of entries to the array list
for (HdfsFileStatus fileStatus : partialListing) {
listing.add(toFileStatus(fileStatus, src));
}
// now fetch more entries
do {
thisListing = namenode.getPartialListing(src, thisListing.getLastName());
if (thisListing == null) {
return null; // the directory is deleted
}
partialListing = thisListing.getPartialListing();
for (HdfsFileStatus fileStatus : partialListing) {
listing.add(toFileStatus(fileStatus, src));
}
} while (thisListing.hasMore());
return listing.toArray(new FileStatus[listing.size()]);
}
public FileStatus getFileInfo(String src) throws IOException {
checkOpen();
try {
if (namenodeProtocolProxy == null) {
return versionBasedGetFileInfo(src);
}
return methodBasedGetFileInfo(src);
} catch(RemoteException re) {
throw re.unwrapRemoteException(AccessControlException.class);
}
}
/** Get file info: decide which rpc to call based on protocol version */
private FileStatus versionBasedGetFileInfo(String src) throws IOException {
if (namenodeVersion >= ClientProtocol.OPTIMIZE_FILE_STATUS_VERSION) {
return toFileStatus(namenode.getHdfsFileInfo(src), src);
} else {
return namenode.getFileInfo(src);
}
}
/** Get file info: decide which rpc to call based on server methods*/
private FileStatus methodBasedGetFileInfo(String src) throws IOException {
if (namenodeProtocolProxy.isMethodSupported(
"getHdfsFileInfo", String.class)) {
return toFileStatus(namenode.getHdfsFileInfo(src), src);
} else {
return namenode.getFileInfo(src);
}
}
/**
* Get the checksum of a file.
* @param src The file path
* @return The checksum
* @see DistributedFileSystem#getFileChecksum(Path)
*/
MD5MD5CRC32FileChecksum getFileChecksum(String src) throws IOException {
checkOpen();
return getFileChecksum(getDataTransferProtocolVersion(),
src, namenode, socketFactory, socketTimeout);
}
/**
* Get the checksum of a file.
* @param src The file path
* @return The checksum
*/
public static MD5MD5CRC32FileChecksum getFileChecksum(
int dataTransferVersion, String src,
ClientProtocol namenode, SocketFactory socketFactory, int socketTimeout
) throws IOException {
//get all block locations
final List<LocatedBlock> locatedblocks
= callGetBlockLocations(namenode, src, 0, Long.MAX_VALUE).getLocatedBlocks();
final DataOutputBuffer md5out = new DataOutputBuffer();
int bytesPerCRC = 0;
long crcPerBlock = 0;
//get block checksum for each block
for(int i = 0; i < locatedblocks.size(); i++) {
LocatedBlock lb = locatedblocks.get(i);
final Block block = lb.getBlock();
final DatanodeInfo[] datanodes = lb.getLocations();
//try each datanode location of the block
final int timeout = 3000 * datanodes.length + socketTimeout;
boolean done = false;
for(int j = 0; !done && j < datanodes.length; j++) {
//connect to a datanode
final Socket sock = socketFactory.createSocket();
NetUtils.connect(sock,
NetUtils.createSocketAddr(datanodes[j].getName()),
timeout);
sock.setSoTimeout(timeout);
DataOutputStream out = new DataOutputStream(
new BufferedOutputStream(NetUtils.getOutputStream(sock),
DataNode.SMALL_BUFFER_SIZE));
DataInputStream in = new DataInputStream(NetUtils.getInputStream(sock));
// get block MD5
try {
if (LOG.isDebugEnabled()) {
LOG.debug("write to " + datanodes[j].getName() + ": "
+ DataTransferProtocol.OP_BLOCK_CHECKSUM +
", block=" + block);
}
out.writeShort(dataTransferVersion);
out.write(DataTransferProtocol.OP_BLOCK_CHECKSUM);
out.writeLong(block.getBlockId());
out.writeLong(block.getGenerationStamp());
out.flush();
final short reply = in.readShort();
if (reply != DataTransferProtocol.OP_STATUS_SUCCESS) {
throw new IOException("Bad response " + reply + " for block "
+ block + " from datanode " + datanodes[j].getName());
}
//read byte-per-checksum
final int bpc = in.readInt();
if (i == 0) { //first block
bytesPerCRC = bpc;
}
else if (bpc != bytesPerCRC) {
throw new IOException("Byte-per-checksum not matched: bpc=" + bpc
+ " but bytesPerCRC=" + bytesPerCRC);
}
//read crc-per-block
final long cpb = in.readLong();
if (locatedblocks.size() > 1 && i == 0) {
crcPerBlock = cpb;
}
//read md5
final MD5Hash md5 = MD5Hash.read(in);
md5.write(md5out);
done = true;
if (LOG.isDebugEnabled()) {
if (i == 0) {
LOG.debug("set bytesPerCRC=" + bytesPerCRC
+ ", crcPerBlock=" + crcPerBlock);
}
LOG.debug("got reply from " + datanodes[j].getName()
+ ": md5=" + md5);
}
} catch (IOException ie) {
LOG.warn("src=" + src + ", datanodes[" + j + "].getName()="
+ datanodes[j].getName(), ie);
} finally {
IOUtils.closeStream(in);
IOUtils.closeStream(out);
IOUtils.closeSocket(sock);
}
}
if (!done) {
throw new IOException("Fail to get block MD5 for " + block);
}
}
//compute file MD5
final MD5Hash fileMD5 = MD5Hash.digest(md5out.getData());
return new MD5MD5CRC32FileChecksum(bytesPerCRC, crcPerBlock, fileMD5);
}
/**
* Set permissions to a file or directory.
* @param src path name.
* @param permission
* @throws <code>FileNotFoundException</code> is file does not exist.
*/
public void setPermission(String src, FsPermission permission
) throws IOException {
checkOpen();
try {
namenode.setPermission(src, permission);
} catch(RemoteException re) {
throw re.unwrapRemoteException(AccessControlException.class,
FileNotFoundException.class);
}
}
/**
* Set file or directory owner.
* @param src path name.
* @param username user id.
* @param groupname user group.
* @throws <code>FileNotFoundException</code> is file does not exist.
*/
public void setOwner(String src, String username, String groupname
) throws IOException {
checkOpen();
try {
namenode.setOwner(src, username, groupname);
} catch(RemoteException re) {
throw re.unwrapRemoteException(AccessControlException.class,
FileNotFoundException.class);
}
}
public DiskStatus getDiskStatus() throws IOException {
long rawNums[] = namenode.getStats();
return new DiskStatus(rawNums[0], rawNums[1], rawNums[2]);
}
/**
*/
public long totalRawCapacity() throws IOException {
long rawNums[] = namenode.getStats();
return rawNums[0];
}
/**
*/
public long totalRawUsed() throws IOException {
long rawNums[] = namenode.getStats();
return rawNums[1];
}
/**
* Returns count of blocks with no good replicas left. Normally should be
* zero.
* @throws IOException
*/
public long getMissingBlocksCount() throws IOException {
return namenode.getStats()[ClientProtocol.GET_STATS_MISSING_BLOCKS_IDX];
}
/**
* Returns count of blocks with one of more replica missing.
* @throws IOException
*/
public long getUnderReplicatedBlocksCount() throws IOException {
return namenode.getStats()[ClientProtocol.GET_STATS_UNDER_REPLICATED_IDX];
}
/**
* Returns count of blocks with at least one replica marked corrupt.
* @throws IOException
*/
public long getCorruptBlocksCount() throws IOException {
return namenode.getStats()[ClientProtocol.GET_STATS_CORRUPT_BLOCKS_IDX];
}
/**
* @return a list in which each entry describes a corrupt file/block
* @throws AccessControlException
* @throws IOException
*/
public CorruptFileBlocks listCorruptFileBlocks(String path,
String cookie)
throws IOException {
if (namenodeProtocolProxy == null) {
return versionBasedListCorruptFileBlocks(path, cookie);
}
return methodBasedListCorruptFileBlocks(path, cookie);
}
/** Version based list corrupt file blocks */
private CorruptFileBlocks versionBasedListCorruptFileBlocks(String path,
String cookie) throws IOException {
if (namenodeVersion < ClientProtocol.LIST_CORRUPT_FILEBLOCKS_VERSION) {
LOG.info("NameNode version is " + namenodeVersion +
" Using older version of getCorruptFiles.");
if (cookie != null ) {
return new CorruptFileBlocks(new String[0], "");
}
ArrayList<String> str = new ArrayList<String>();
for (FileStatus stat : namenode.getCorruptFiles()) {
String filename = stat.getPath().toUri().getPath();
if (filename.startsWith(path)) {
str.add(filename);
}
}
return new CorruptFileBlocks(str.toArray(new String[str.size()]), "");
}
return namenode.listCorruptFileBlocks(path, cookie);
}
/** Method based listCorruptFileBlocks */
private CorruptFileBlocks methodBasedListCorruptFileBlocks(String path,
String cookie) throws IOException {
if (!namenodeProtocolProxy.isMethodSupported("listCorruptFileBlocks",
String.class, String.class)) {
LOG.info("NameNode version is " + namenodeVersion +
" Using older version of getCorruptFiles.");
if (cookie != null ) {
return new CorruptFileBlocks(new String[0], "");
}
ArrayList<String> str = new ArrayList<String>();
for (FileStatus stat : namenode.getCorruptFiles()) {
String filename = stat.getPath().toUri().getPath();
if (filename.startsWith(path)) {
str.add(filename);
}
}
return new CorruptFileBlocks(str.toArray(new String[str.size()]), "");
}
return namenode.listCorruptFileBlocks(path, cookie);
}
public DatanodeInfo[] datanodeReport(DatanodeReportType type)
throws IOException {
return namenode.getDatanodeReport(type);
}
/**
* Enter, leave or get safe mode.
* See {@link ClientProtocol#setSafeMode(FSConstants.SafeModeAction)}
* for more details.
*
* @see ClientProtocol#setSafeMode(FSConstants.SafeModeAction)
*/
public boolean setSafeMode(SafeModeAction action) throws IOException {
return namenode.setSafeMode(action);
}
/**
* Save namespace image.
* See {@link ClientProtocol#saveNamespace()}
* for more details.
*
* @see ClientProtocol#saveNamespace()
*/
void saveNamespace(boolean force, boolean uncompressed)
throws AccessControlException, IOException {
try {
if (namenodeProtocolProxy == null) {
versionBasedSaveNamespace(force, uncompressed);
} else {
methodBasedSaveNamespace(force, uncompressed);
}
} catch(RemoteException re) {
throw re.unwrapRemoteException(AccessControlException.class);
}
}
/** Version-based save namespace */
private void versionBasedSaveNamespace(boolean force, boolean uncompressed)
throws AccessControlException, IOException {
if (namenodeVersion >= ClientProtocol.SAVENAMESPACE_FORCE) {
namenode.saveNamespace(force, uncompressed);
} else {
namenode.saveNamespace();
}
}
/** Method-based save namespace */
private void methodBasedSaveNamespace(boolean force, boolean uncompressed)
throws AccessControlException, IOException {
if (namenodeProtocolProxy.isMethodSupported(
"saveNamespace", boolean.class, boolean.class)) {
namenode.saveNamespace(force, uncompressed);
} else {
namenode.saveNamespace();
}
}
/**
* Refresh the hosts and exclude files. (Rereads them.)
* See {@link ClientProtocol#refreshNodes()}
* for more details.
*
* @see ClientProtocol#refreshNodes()
*/
public void refreshNodes() throws IOException {
namenode.refreshNodes();
}
/**
* Dumps DFS data structures into specified file.
* See {@link ClientProtocol#metaSave(String)}
* for more details.
*
* @see ClientProtocol#metaSave(String)
*/
public void metaSave(String pathname) throws IOException {
namenode.metaSave(pathname);
}
/**
* @see ClientProtocol#finalizeUpgrade()
*/
public void finalizeUpgrade() throws IOException {
namenode.finalizeUpgrade();
}
/**
* @see ClientProtocol#distributedUpgradeProgress(FSConstants.UpgradeAction)
*/
public UpgradeStatusReport distributedUpgradeProgress(UpgradeAction action
) throws IOException {
return namenode.distributedUpgradeProgress(action);
}
/**
*/
public boolean mkdirs(String src) throws IOException {
return mkdirs(src, null);
}
/**
* Create a directory (or hierarchy of directories) with the given
* name and permission.
*
* @param src The path of the directory being created
* @param permission The permission of the directory being created.
* If permission == null, use {@link FsPermission#getDefault()}.
* @return True if the operation success.
* @see ClientProtocol#mkdirs(String, FsPermission)
*/
public boolean mkdirs(String src, FsPermission permission)throws IOException{
checkOpen();
if (permission == null) {
permission = FsPermission.getDefault();
}
FsPermission masked = permission.applyUMask(FsPermission.getUMask(conf));
LOG.debug(src + ": masked=" + masked);
try {
return namenode.mkdirs(src, masked);
} catch(RemoteException re) {
throw re.unwrapRemoteException(AccessControlException.class,
NSQuotaExceededException.class,
DSQuotaExceededException.class);
}
}
ContentSummary getContentSummary(String src) throws IOException {
try {
return namenode.getContentSummary(src);
} catch(RemoteException re) {
throw re.unwrapRemoteException(AccessControlException.class,
FileNotFoundException.class);
}
}
/**
* Sets or resets quotas for a directory.
* @see org.apache.hadoop.hdfs.protocol.ClientProtocol#setQuota(String, long, long)
*/
void setQuota(String src, long namespaceQuota, long diskspaceQuota)
throws IOException {
// sanity check
if ((namespaceQuota <= 0 && namespaceQuota != FSConstants.QUOTA_DONT_SET &&
namespaceQuota != FSConstants.QUOTA_RESET) ||
(diskspaceQuota <= 0 && diskspaceQuota != FSConstants.QUOTA_DONT_SET &&
diskspaceQuota != FSConstants.QUOTA_RESET)) {
throw new IllegalArgumentException("Invalid values for quota : " +
namespaceQuota + " and " +
diskspaceQuota);
}
try {
namenode.setQuota(src, namespaceQuota, diskspaceQuota);
} catch(RemoteException re) {
throw re.unwrapRemoteException(AccessControlException.class,
FileNotFoundException.class,
NSQuotaExceededException.class,
DSQuotaExceededException.class);
}
}
/**
* set the modification and access time of a file
* @throws FileNotFoundException if the path is not a file
*/
public void setTimes(String src, long mtime, long atime) throws IOException {
checkOpen();
try {
namenode.setTimes(src, mtime, atime);
} catch(RemoteException re) {
throw re.unwrapRemoteException(AccessControlException.class,
FileNotFoundException.class);
}
}
/**
* Pick the best node from which to stream the data.
* Entries in <i>nodes</i> are already in the priority order
*/
private DatanodeInfo bestNode(DatanodeInfo nodes[],
AbstractMap<DatanodeInfo, DatanodeInfo> deadNodes)
throws IOException {
if (nodes != null) {
for (int i = 0; i < nodes.length; i++) {
if (!deadNodes.containsKey(nodes[i])) {
return nodes[i];
}
}
}
throw new IOException("No live nodes contain current block");
}
boolean isLeaseCheckerStarted() {
return leasechecker.daemon != null;
}
/** Lease management*/
class LeaseChecker implements Runnable {
/** A map from src -> DFSOutputStream of files that are currently being
* written by this client.
*/
private final SortedMap<String, OutputStream> pendingCreates
= new TreeMap<String, OutputStream>();
private Daemon daemon = null;
synchronized void put(String src, OutputStream out) {
if (clientRunning) {
if (daemon == null) {
daemon = new Daemon(this);
daemon.start();
}
pendingCreates.put(src, out);
}
}
synchronized void remove(String src) {
pendingCreates.remove(src);
}
void interruptAndJoin() throws InterruptedException {
Daemon daemonCopy = null;
synchronized (this) {
if (daemon != null) {
daemon.interrupt();
daemonCopy = daemon;
}
}
if (daemonCopy != null) {
LOG.debug("Wait for lease checker to terminate");
daemonCopy.join();
}
}
synchronized void close() {
while (!pendingCreates.isEmpty()) {
String src = pendingCreates.firstKey();
OutputStream out = pendingCreates.remove(src);
if (out != null) {
try {
out.close();
} catch (IOException ie) {
LOG.error("Exception closing file " + src+ " : " + ie, ie);
}
}
}
}
/**
* Abort all open files. Release resources held. Ignore all errors.
*/
synchronized void abort() {
clientRunning = false;
while (!pendingCreates.isEmpty()) {
String src = pendingCreates.firstKey();
DFSOutputStream out = (DFSOutputStream)pendingCreates.remove(src);
if (out != null) {
try {
out.abort();
} catch (IOException ie) {
LOG.error("Exception aborting file " + src+ ": ", ie);
}
}
}
RPC.stopProxy(rpcNamenode); // close connections to the namenode
}
private void renew() throws IOException {
synchronized(this) {
if (pendingCreates.isEmpty()) {
return;
}
}
namenode.renewLease(clientName);
}
/**
* Periodically check in with the namenode and renew all the leases
* when the lease period is half over.
*/
public void run() {
long lastRenewed = 0;
long hardLeaseLimit = conf.getLong(
FSConstants.DFS_HARD_LEASE_KEY, LEASE_HARDLIMIT_PERIOD);
long softLeaseLimit = conf.getLong(
FSConstants.DFS_SOFT_LEASE_KEY, LEASE_SOFTLIMIT_PERIOD);
long renewal = Math.min(hardLeaseLimit, softLeaseLimit) / 2;
if (hdfsTimeout > 0) {
renewal = Math.min(renewal, hdfsTimeout/2);
}
while (clientRunning && !Thread.interrupted()) {
if (System.currentTimeMillis() - lastRenewed > renewal) {
try {
renew();
lastRenewed = System.currentTimeMillis();
} catch (SocketTimeoutException ie) {
LOG.warn("Problem renewing lease for " + clientName +
" for a period of " + (renewal/1000) +
" seconds. Shutting down HDFS client...", ie);
abort();
break;
} catch (IOException ie) {
LOG.warn("Problem renewing lease for " + clientName +
" for a period of " + (renewal/1000) +
" seconds. Will retry shortly...", ie);
}
}
try {
Thread.sleep(1000);
} catch (InterruptedException ie) {
if (LOG.isDebugEnabled()) {
LOG.debug(this + " is interrupted.", ie);
}
return;
}
}
}
/** {@inheritDoc} */
public String toString() {
String s = getClass().getSimpleName();
if (LOG.isTraceEnabled()) {
return s + "@" + DFSClient.this + ": "
+ StringUtils.stringifyException(new Throwable("for testing"));
}
return s;
}
}
/** Utility class to encapsulate data node info and its ip address. */
private static class DNAddrPair {
DatanodeInfo info;
InetSocketAddress addr;
DNAddrPair(DatanodeInfo info, InetSocketAddress addr) {
this.info = info;
this.addr = addr;
}
}
/** This is a wrapper around connection to datadone
* and understands checksum, offset etc
*/
public static class BlockReader extends FSInputChecker {
private Socket dnSock; //for now just sending checksumOk.
private DataInputStream in;
private DataChecksum checksum;
private long lastChunkOffset = -1;
private long lastChunkLen = -1;
private long lastSeqNo = -1;
private long startOffset;
private long firstChunkOffset;
private int bytesPerChecksum;
private int checksumSize;
private boolean gotEOS = false;
byte[] skipBuf = null;
ByteBuffer checksumBytes = null;
int dataLeft = 0;
boolean isLastPacket = false;
/* FSInputChecker interface */
/* same interface as inputStream java.io.InputStream#read()
* used by DFSInputStream#read()
* This violates one rule when there is a checksum error:
* "Read should not modify user buffer before successful read"
* because it first reads the data to user buffer and then checks
* the checksum.
*/
@Override
public synchronized int read(byte[] buf, int off, int len)
throws IOException {
//for the first read, skip the extra bytes at the front.
if (lastChunkLen < 0 && startOffset > firstChunkOffset && len > 0) {
// Skip these bytes. But don't call this.skip()!
int toSkip = (int)(startOffset - firstChunkOffset);
if ( skipBuf == null ) {
skipBuf = new byte[bytesPerChecksum];
}
if ( super.read(skipBuf, 0, toSkip) != toSkip ) {
// should never happen
throw new IOException("Could not skip required number of bytes");
}
}
boolean eosBefore = gotEOS;
int nRead = super.read(buf, off, len);
// if gotEOS was set in the previous read and checksum is enabled :
if (dnSock != null && gotEOS && !eosBefore && nRead >= 0 && needChecksum()) {
//checksum is verified and there are no errors.
checksumOk(dnSock);
}
return nRead;
}
@Override
public synchronized long skip(long n) throws IOException {
/* How can we make sure we don't throw a ChecksumException, at least
* in majority of the cases?. This one throws. */
if ( skipBuf == null ) {
skipBuf = new byte[bytesPerChecksum];
}
long nSkipped = 0;
while ( nSkipped < n ) {
int toSkip = (int)Math.min(n-nSkipped, skipBuf.length);
int ret = read(skipBuf, 0, toSkip);
if ( ret <= 0 ) {
return nSkipped;
}
nSkipped += ret;
}
return nSkipped;
}
@Override
public int read() throws IOException {
throw new IOException("read() is not expected to be invoked. " +
"Use read(buf, off, len) instead.");
}
@Override
public boolean seekToNewSource(long targetPos) throws IOException {
/* Checksum errors are handled outside the BlockReader.
* DFSInputStream does not always call 'seekToNewSource'. In the
* case of pread(), it just tries a different replica without seeking.
*/
return false;
}
@Override
public void seek(long pos) throws IOException {
throw new IOException("Seek() is not supported in BlockInputChecker");
}
@Override
protected long getChunkPosition(long pos) {
throw new RuntimeException("getChunkPosition() is not supported, " +
"since seek is not required");
}
/**
* Makes sure that checksumBytes has enough capacity
* and limit is set to the number of checksum bytes needed
* to be read.
*/
private void adjustChecksumBytes(int dataLen) {
int requiredSize =
((dataLen + bytesPerChecksum - 1)/bytesPerChecksum)*checksumSize;
if (checksumBytes == null || requiredSize > checksumBytes.capacity()) {
checksumBytes = ByteBuffer.wrap(new byte[requiredSize]);
} else {
checksumBytes.clear();
}
checksumBytes.limit(requiredSize);
}
@Override
protected synchronized int readChunk(long pos, byte[] buf, int offset,
int len, byte[] checksumBuf)
throws IOException {
// Read one chunk.
if ( gotEOS ) {
if ( startOffset < 0 ) {
//This is mainly for debugging. can be removed.
throw new IOException( "BlockRead: already got EOS or an error" );
}
startOffset = -1;
return -1;
}
// Read one DATA_CHUNK.
long chunkOffset = lastChunkOffset;
if ( lastChunkLen > 0 ) {
chunkOffset += lastChunkLen;
}
if ( (pos + firstChunkOffset) != chunkOffset ) {
throw new IOException("Mismatch in pos : " + pos + " + " +
firstChunkOffset + " != " + chunkOffset);
}
// Read next packet if the previous packet has been read completely.
if (dataLeft <= 0) {
//Read packet headers.
int packetLen = in.readInt();
long offsetInBlock = in.readLong();
long seqno = in.readLong();
boolean lastPacketInBlock = in.readBoolean();
if (LOG.isDebugEnabled()) {
LOG.debug("DFSClient readChunk got seqno " + seqno +
" offsetInBlock " + offsetInBlock +
" lastPacketInBlock " + lastPacketInBlock +
" packetLen " + packetLen);
}
int dataLen = in.readInt();
// Sanity check the lengths
if ( dataLen < 0 ||
( (dataLen % bytesPerChecksum) != 0 && !lastPacketInBlock ) ||
(seqno != (lastSeqNo + 1)) ) {
throw new IOException("BlockReader: error in packet header" +
"(chunkOffset : " + chunkOffset +
", dataLen : " + dataLen +
", seqno : " + seqno +
" (last: " + lastSeqNo + "))");
}
lastSeqNo = seqno;
isLastPacket = lastPacketInBlock;
dataLeft = dataLen;
adjustChecksumBytes(dataLen);
if (dataLen > 0) {
IOUtils.readFully(in, checksumBytes.array(), 0,
checksumBytes.limit());
}
}
int chunkLen = Math.min(dataLeft, bytesPerChecksum);
if ( chunkLen > 0 ) {
// len should be >= chunkLen
IOUtils.readFully(in, buf, offset, chunkLen);
checksumBytes.get(checksumBuf, 0, checksumSize);
}
dataLeft -= chunkLen;
lastChunkOffset = chunkOffset;
lastChunkLen = chunkLen;
if ((dataLeft == 0 && isLastPacket) || chunkLen == 0) {
gotEOS = true;
}
if ( chunkLen == 0 ) {
return -1;
}
return chunkLen;
}
private BlockReader( String file, long blockId, DataInputStream in,
DataChecksum checksum, boolean verifyChecksum,
long startOffset, long firstChunkOffset,
Socket dnSock ) {
super(new Path("/blk_" + blockId + ":of:" + file)/*too non path-like?*/,
1, verifyChecksum,
checksum.getChecksumSize() > 0? checksum : null,
checksum.getBytesPerChecksum(),
checksum.getChecksumSize());
this.dnSock = dnSock;
this.in = in;
this.checksum = checksum;
this.startOffset = Math.max( startOffset, 0 );
this.firstChunkOffset = firstChunkOffset;
lastChunkOffset = firstChunkOffset;
lastChunkLen = -1;
bytesPerChecksum = this.checksum.getBytesPerChecksum();
checksumSize = this.checksum.getChecksumSize();
}
/**
* Public constructor
*/
BlockReader(String file, int numRetries) {
super(new Path(file), numRetries);
}
public static BlockReader newBlockReader(int dataTransferVersion,
Socket sock, String file, long blockId,
long genStamp, long startOffset, long len, int bufferSize) throws IOException {
return newBlockReader(dataTransferVersion,
sock, file, blockId, genStamp, startOffset, len, bufferSize,
true);
}
/** Java Doc required */
public static BlockReader newBlockReader( int dataTransferVersion,
Socket sock, String file, long blockId,
long genStamp,
long startOffset, long len,
int bufferSize, boolean verifyChecksum)
throws IOException {
return newBlockReader(dataTransferVersion, sock, file, blockId, genStamp,
startOffset,
len, bufferSize, verifyChecksum, "");
}
public static BlockReader newBlockReader( int dataTransferVersion,
Socket sock, String file,
long blockId,
long genStamp,
long startOffset, long len,
int bufferSize, boolean verifyChecksum,
String clientName)
throws IOException {
// in and out will be closed when sock is closed (by the caller)
DataOutputStream out = new DataOutputStream(
new BufferedOutputStream(NetUtils.getOutputStream(sock,HdfsConstants.WRITE_TIMEOUT)));
//write the header.
out.writeShort( dataTransferVersion );
out.write( DataTransferProtocol.OP_READ_BLOCK );
out.writeLong( blockId );
out.writeLong( genStamp );
out.writeLong( startOffset );
out.writeLong( len );
Text.writeString(out, clientName);
out.flush();
//
// Get bytes in block, set streams
//
DataInputStream in = new DataInputStream(
new BufferedInputStream(NetUtils.getInputStream(sock),
bufferSize));
if ( in.readShort() != DataTransferProtocol.OP_STATUS_SUCCESS ) {
throw new IOException("Got error in response to OP_READ_BLOCK " +
"for file " + file +
" for block " + blockId);
}
DataChecksum checksum = DataChecksum.newDataChecksum( in );
//Warning when we get CHECKSUM_NULL?
// Read the first chunk offset.
long firstChunkOffset = in.readLong();
if ( firstChunkOffset < 0 || firstChunkOffset > startOffset ||
firstChunkOffset >= (startOffset + checksum.getBytesPerChecksum())) {
throw new IOException("BlockReader: error in first chunk offset (" +
firstChunkOffset + ") startOffset is " +
startOffset + " for file " + file);
}
return new BlockReader( file, blockId, in, checksum, verifyChecksum,
startOffset, firstChunkOffset, sock );
}
@Override
public synchronized void close() throws IOException {
startOffset = -1;
checksum = null;
// in will be closed when its Socket is closed.
}
/** kind of like readFully(). Only reads as much as possible.
* And allows use of protected readFully().
*/
public int readAll(byte[] buf, int offset, int len) throws IOException {
return readFully(this, buf, offset, len);
}
/* When the reader reaches end of a block and there are no checksum
* errors, we send OP_STATUS_CHECKSUM_OK to datanode to inform that
* checksum was verified and there was no error.
*/
private void checksumOk(Socket sock) {
try {
OutputStream out = NetUtils.getOutputStream(sock, HdfsConstants.WRITE_TIMEOUT);
byte buf[] = { (DataTransferProtocol.OP_STATUS_CHECKSUM_OK >>> 8) & 0xff,
(DataTransferProtocol.OP_STATUS_CHECKSUM_OK) & 0xff };
out.write(buf);
out.flush();
} catch (IOException e) {
// its ok not to be able to send this.
LOG.debug("Could not write to datanode " + sock.getInetAddress() +
": " + e.getMessage());
}
}
}
/****************************************************************
* DFSInputStream provides bytes from a named file. It handles
* negotiation of the namenode and various datanodes as necessary.
****************************************************************/
public class DFSInputStream extends FSInputStream {
private Socket s = null;
private boolean closed = false;
private String src;
private long prefetchSize = 10 * defaultBlockSize;
private BlockReader blockReader = null;
private boolean verifyChecksum;
private LocatedBlocks locatedBlocks = null;
private DatanodeInfo currentNode = null;
private Block currentBlock = null;
private long pos = 0;
private long blockEnd = -1;
private int failures = 0;
private int timeWindow = 3000; // wait time window (in msec) if BlockMissingException is caught
/* XXX Use of CocurrentHashMap is temp fix. Need to fix
* parallel accesses to DFSInputStream (through ptreads) properly */
private ConcurrentHashMap<DatanodeInfo, DatanodeInfo> deadNodes =
new ConcurrentHashMap<DatanodeInfo, DatanodeInfo>();
private int buffersize = 1;
private byte[] oneByteBuf = new byte[1]; // used for 'int read()'
void addToDeadNodes(DatanodeInfo dnInfo) {
deadNodes.put(dnInfo, dnInfo);
}
DFSInputStream(String src, int buffersize, boolean verifyChecksum
) throws IOException {
this.verifyChecksum = verifyChecksum;
this.buffersize = buffersize;
this.src = src;
prefetchSize = conf.getLong("dfs.read.prefetch.size", prefetchSize);
timeWindow = conf.getInt("dfs.client.baseTimeWindow.waitOn.BlockMissingException", timeWindow);
openInfo();
}
/**
* Grab the open-file info from namenode
*/
synchronized void openInfo() throws IOException {
LocatedBlocks newInfo = callGetBlockLocations(namenode, src, 0, prefetchSize);
if (newInfo == null) {
throw new IOException("Cannot open filename " + src);
}
if (locatedBlocks != null) {
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())) {
throw new IOException("Blocklist for " + src + " has changed!");
}
}
}
this.locatedBlocks = newInfo;
this.currentNode = null;
}
/**
* Returns whether the file opened is under construction.
*/
public synchronized boolean isUnderConstruction() {
return locatedBlocks.isUnderConstruction();
}
public synchronized long getFileLength() {
return (locatedBlocks == null) ? 0 : locatedBlocks.getFileLength();
}
/**
* Returns the datanode from which the stream is currently reading.
*/
public DatanodeInfo getCurrentDatanode() {
return currentNode;
}
/**
* Returns the block containing the target position.
*/
public Block getCurrentBlock() {
return currentBlock;
}
/**
* Return collection of blocks that has already been located.
*/
synchronized List<LocatedBlock> getAllBlocks() throws IOException {
return getBlockRange(0, this.getFileLength());
}
/**
* Get block at the specified position.
* Fetch it from the namenode if not cached.
*
* @param offset
* @return located block
* @throws IOException
*/
private LocatedBlock getBlockAt(long offset) throws IOException {
assert (locatedBlocks != null) : "locatedBlocks is null";
// search cached blocks first
int targetBlockIdx = locatedBlocks.findBlock(offset);
if (targetBlockIdx < 0) { // block is not cached
targetBlockIdx = LocatedBlocks.getInsertIndex(targetBlockIdx);
// fetch more blocks
LocatedBlocks newBlocks;
newBlocks = callGetBlockLocations(namenode, src, offset, prefetchSize);
assert (newBlocks != null) : "Could not find target position " + offset;
locatedBlocks.insertRange(targetBlockIdx, newBlocks.getLocatedBlocks());
}
LocatedBlock blk = locatedBlocks.get(targetBlockIdx);
// update current position
this.pos = offset;
this.blockEnd = blk.getStartOffset() + blk.getBlockSize() - 1;
this.currentBlock = blk.getBlock();
return blk;
}
/**
* Get blocks in the specified range.
* Fetch them from the namenode if not cached.
*
* @param offset
* @param length
* @return consequent segment of located blocks
* @throws IOException
*/
private synchronized List<LocatedBlock> getBlockRange(long offset,
long length)
throws IOException {
assert (locatedBlocks != null) : "locatedBlocks is null";
List<LocatedBlock> blockRange = new ArrayList<LocatedBlock>();
// search cached blocks first
int blockIdx = locatedBlocks.findBlock(offset);
if (blockIdx < 0) { // block is not cached
blockIdx = LocatedBlocks.getInsertIndex(blockIdx);
}
long remaining = length;
long curOff = offset;
while(remaining > 0) {
LocatedBlock blk = null;
if(blockIdx < locatedBlocks.locatedBlockCount())
blk = locatedBlocks.get(blockIdx);
if (blk == null || curOff < blk.getStartOffset()) {
LocatedBlocks newBlocks;
newBlocks = callGetBlockLocations(namenode, src, curOff, remaining);
locatedBlocks.insertRange(blockIdx, newBlocks.getLocatedBlocks());
continue;
}
assert curOff >= blk.getStartOffset() : "Block not found";
blockRange.add(blk);
long bytesRead = blk.getStartOffset() + blk.getBlockSize() - curOff;
remaining -= bytesRead;
curOff += bytesRead;
blockIdx++;
}
return blockRange;
}
/**
* Open a DataInputStream to a DataNode so that it can be read from.
* We get block ID and the IDs of the destinations at startup, from the namenode.
*/
private synchronized DatanodeInfo blockSeekTo(long target) throws IOException {
if (target >= getFileLength()) {
throw new IOException("Attempted to read past end of file");
}
if ( blockReader != null ) {
blockReader.close();
blockReader = null;
}
if (s != null) {
s.close();
s = null;
}
//
// Compute desired block
//
LocatedBlock targetBlock = getBlockAt(target);
assert (target==this.pos) : "Wrong postion " + pos + " expect " + target;
long offsetIntoBlock = target - targetBlock.getStartOffset();
//
// Connect to best DataNode for desired Block, with potential offset
//
DatanodeInfo chosenNode = null;
failures = 0;
while (s == null) {
DNAddrPair retval = chooseDataNode(targetBlock);
chosenNode = retval.info;
InetSocketAddress targetAddr = retval.addr;
// try reading the block locally. if this fails, then go via
// the datanode
Block blk = targetBlock.getBlock();
try {
if (LOG.isDebugEnabled()) {
LOG.warn("blockSeekTo shortCircuitLocalReads " + shortCircuitLocalReads +
" localhost " + localHost +
" targetAddr " + targetAddr);
}
if (shortCircuitLocalReads && localHost != null &&
(targetAddr.equals(localHost) ||
targetAddr.getHostName().startsWith("localhost"))) {
blockReader = BlockReaderLocal.newBlockReader(conf, src, blk,
chosenNode,
offsetIntoBlock,
blk.getNumBytes() - offsetIntoBlock,
metrics);
return chosenNode;
}
} catch (IOException ex) {
LOG.info("Failed to read block " + targetBlock.getBlock() +
" on local machine " + localHost +
". Try via the datanode on " + targetAddr + ":"
+ StringUtils.stringifyException(ex));
}
try {
s = socketFactory.createSocket();
NetUtils.connect(s, targetAddr, socketTimeout);
s.setSoTimeout(socketTimeout);
blockReader = BlockReader.newBlockReader(
getDataTransferProtocolVersion(),
s, src, blk.getBlockId(),
blk.getGenerationStamp(),
offsetIntoBlock, blk.getNumBytes() - offsetIntoBlock,
buffersize, verifyChecksum, clientName);
return chosenNode;
} catch (IOException ex) {
// Put chosen node into dead list, continue
LOG.debug("Failed to connect to " + targetAddr + ":"
+ StringUtils.stringifyException(ex));
addToDeadNodes(chosenNode);
if (s != null) {
try {
s.close();
} catch (IOException iex) {
}
}
s = null;
}
}
return chosenNode;
}
/**
* Close it down!
*/
@Override
public synchronized void close() throws IOException {
if (closed) {
return;
}
checkOpen();
if ( blockReader != null ) {
blockReader.close();
blockReader = null;
}
if (s != null) {
s.close();
s = null;
}
super.close();
closed = true;
}
@Override
public synchronized int read() throws IOException {
int ret = read( oneByteBuf, 0, 1 );
return ( ret <= 0 ) ? -1 : (oneByteBuf[0] & 0xff);
}
/* This is a used by regular read() and handles ChecksumExceptions.
* name readBuffer() is chosen to imply similarity to readBuffer() in
* ChecksuFileSystem
*/
private synchronized int readBuffer(byte buf[], int off, int len)
throws IOException {
IOException ioe;
/* we retry current node only once. So this is set to true only here.
* Intention is to handle one common case of an error that is not a
* failure on datanode or client : when DataNode closes the connection
* since client is idle. If there are other cases of "non-errors" then
* then a datanode might be retried by setting this to true again.
*/
boolean retryCurrentNode = true;
while (true) {
// retry as many times as seekToNewSource allows.
try {
return blockReader.read(buf, off, len);
} catch ( ChecksumException ce ) {
LOG.warn("Found Checksum error for " + currentBlock + " from " +
currentNode.getName() + " at " + ce.getPos());
reportChecksumFailure(src, currentBlock, currentNode);
ioe = ce;
retryCurrentNode = false;
} catch ( IOException e ) {
if (!retryCurrentNode) {
LOG.warn("Exception while reading from " + currentBlock +
" of " + src + " from " + currentNode + ": " +
StringUtils.stringifyException(e));
}
ioe = e;
}
boolean sourceFound = false;
if (retryCurrentNode) {
/* possibly retry the same node so that transient errors don't
* result in application level failures (e.g. Datanode could have
* closed the connection because the client is idle for too long).
*/
sourceFound = seekToBlockSource(pos);
} else {
addToDeadNodes(currentNode);
sourceFound = seekToNewSource(pos);
}
if (!sourceFound) {
throw ioe;
}
retryCurrentNode = false;
}
}
/**
* Read the entire buffer.
*/
@Override
public synchronized int read(byte buf[], int off, int len) throws IOException {
checkOpen();
if (closed) {
throw new IOException("Stream closed");
}
if (pos < getFileLength()) {
int retries = 2;
while (retries > 0) {
try {
if (pos > blockEnd) {
currentNode = blockSeekTo(pos);
}
int realLen = (int) Math.min((long) len, (blockEnd - pos + 1L));
int result = readBuffer(buf, off, realLen);
if (result >= 0) {
pos += result;
} else {
// got a EOS from reader though we expect more data on it.
throw new IOException("Unexpected EOS from the reader");
}
if (stats != null && result != -1) {
stats.incrementBytesRead(result);
}
return result;
} catch (ChecksumException ce) {
throw ce;
} catch (IOException e) {
if (retries == 1) {
LOG.warn("DFS Read: " + StringUtils.stringifyException(e));
}
blockEnd = -1;
if (currentNode != null) { addToDeadNodes(currentNode); }
if (--retries == 0) {
throw e;
}
}
}
}
return -1;
}
private DNAddrPair chooseDataNode(LocatedBlock block)
throws IOException {
while (true) {
DatanodeInfo[] nodes = block.getLocations();
DatanodeInfo chosenNode = null;
try {
chosenNode = bestNode(nodes, deadNodes);
InetSocketAddress targetAddr =
NetUtils.createSocketAddr(chosenNode.getName());
return new DNAddrPair(chosenNode, targetAddr);
} catch (IOException ie) {
String blockInfo = block.getBlock() + " file=" + src;
if (failures >= maxBlockAcquireFailures) {
throw new BlockMissingException(src, "Could not obtain block: " + blockInfo, block.getStartOffset());
}
if (nodes == null || nodes.length == 0) {
LOG.info("No node available for block: " + blockInfo);
}
LOG.info("Could not obtain block " + block.getBlock() +
" from node: " + (chosenNode == null ? " " : chosenNode.getHostName()) +
ie);
try {
// Introducing a random factor to the wait time before another retry.
// The wait time is dependent on # of failures and a random factor.
// At the first time of getting a BlockMissingException, the wait time
// is a random number between 0..3000 ms. If the first retry
// still fails, we will wait 3000 ms grace period before the 2nd retry.
// Also at the second retry, the waiting window is expanded to 6000 ms
// alleviating the request rate from the server. Similarly the 3rd retry
// will wait 6000ms grace period before retry and the waiting window is
// expanded to 9000ms.
double waitTime = timeWindow * failures + // grace period for the last round of attempt
timeWindow * (failures + 1) * r.nextDouble(); // expanding time window for each failure
LOG.warn("DFS chooseDataNode: got # " + (failures + 1) + " IOException, will wait for " + waitTime + " msec.");
Thread.sleep((long)waitTime);
} catch (InterruptedException iex) {
}
deadNodes.clear(); //2nd option is to remove only nodes[blockId]
openInfo();
block = getBlockAt(block.getStartOffset());
failures++;
continue;
}
}
}
private void fetchBlockByteRange(LocatedBlock block, long start,
long end, byte[] buf, int offset) throws IOException {
//
// Connect to best DataNode for desired Block, with potential offset
//
Socket dn = null;
int numAttempts = block.getLocations().length;
IOException ioe = null;
failures = 0;
while (dn == null && numAttempts-- > 0 ) {
DNAddrPair retval = chooseDataNode(block);
DatanodeInfo chosenNode = retval.info;
InetSocketAddress targetAddr = retval.addr;
BlockReader reader = null;
int len = (int) (end - start + 1);
try {
if (LOG.isDebugEnabled()) {
LOG.debug("fetchBlockByteRange shortCircuitLocalReads " +
shortCircuitLocalReads +
" localhst " + localHost +
" targetAddr " + targetAddr);
}
// first try reading the block locally.
if (shortCircuitLocalReads && localHost != null &&
(targetAddr.equals(localHost) ||
targetAddr.getHostName().startsWith("localhost"))) {
reader = BlockReaderLocal.newBlockReader(conf, src,
block.getBlock(),
chosenNode,
start,
len,
metrics);
} else {
// go to the datanode
dn = socketFactory.createSocket();
NetUtils.connect(dn, targetAddr, socketTimeout);
dn.setSoTimeout(socketTimeout);
reader = BlockReader.newBlockReader(getDataTransferProtocolVersion(),
dn, src,
block.getBlock().getBlockId(),
block.getBlock().getGenerationStamp(),
start, len, buffersize,
verifyChecksum, clientName);
}
int nread = reader.readAll(buf, offset, len);
if (nread != len) {
throw new IOException("truncated return from reader.read(): " +
"excpected " + len + ", got " + nread);
}
return;
} catch (ChecksumException e) {
ioe = e;
LOG.warn("fetchBlockByteRange(). Got a checksum exception for " +
src + " at " + block.getBlock() + ":" +
e.getPos() + " from " + chosenNode.getName());
reportChecksumFailure(src, block.getBlock(), chosenNode);
} catch (IOException e) {
ioe = e;
LOG.warn("Failed to connect to " + targetAddr +
" for file " + src +
" for block " + block.getBlock().getBlockId() + ":" +
StringUtils.stringifyException(e));
} finally {
IOUtils.closeStream(reader);
IOUtils.closeSocket(dn);
dn = null;
}
// Put chosen node into dead list, continue
addToDeadNodes(chosenNode);
}
throw (ioe == null) ? new IOException("Could not read data") : ioe;
}
/**
* Read bytes starting from the specified position.
*
* @param position start read from this position
* @param buffer read buffer
* @param offset offset into buffer
* @param length number of bytes to read
*
* @return actual number of bytes read
*/
@Override
public int read(long position, byte[] buffer, int offset, int length)
throws IOException {
// sanity checks
checkOpen();
if (closed) {
throw new IOException("Stream closed");
}
long filelen = getFileLength();
if ((position < 0) || (position >= filelen)) {
return -1;
}
int realLen = length;
if ((position + length) > filelen) {
realLen = (int)(filelen - position);
}
// determine the block and byte range within the block
// corresponding to position and realLen
List<LocatedBlock> blockRange = getBlockRange(position, realLen);
int remaining = realLen;
for (LocatedBlock blk : blockRange) {
long targetStart = position - blk.getStartOffset();
long bytesToRead = Math.min(remaining, blk.getBlockSize() - targetStart);
fetchBlockByteRange(blk, targetStart,
targetStart + bytesToRead - 1, buffer, offset);
remaining -= bytesToRead;
position += bytesToRead;
offset += bytesToRead;
}
assert remaining == 0 : "Wrong number of bytes read.";
if (stats != null) {
stats.incrementBytesRead(realLen);
}
return realLen;
}
@Override
public long skip(long n) throws IOException {
if ( n > 0 ) {
long curPos = getPos();
long fileLen = getFileLength();
if( n+curPos > fileLen ) {
n = fileLen - curPos;
}
seek(curPos+n);
return n;
}
return n < 0 ? -1 : 0;
}
/**
* Seek to a new arbitrary location
*/
@Override
public synchronized void seek(long targetPos) throws IOException {
if (targetPos > getFileLength()) {
throw new IOException("Cannot seek after EOF");
}
boolean done = false;
if (pos <= targetPos && targetPos <= blockEnd) {
//
// If this seek is to a positive position in the current
// block, and this piece of data might already be lying in
// the TCP buffer, then just eat up the intervening data.
//
int diff = (int)(targetPos - pos);
if (diff <= TCP_WINDOW_SIZE) {
try {
pos += blockReader.skip(diff);
if (pos == targetPos) {
done = true;
}
} catch (IOException e) {//make following read to retry
LOG.debug("Exception while seek to " + targetPos + " from "
+ currentBlock +" of " + src + " from " + currentNode +
": " + StringUtils.stringifyException(e));
}
}
}
if (!done) {
pos = targetPos;
blockEnd = -1;
}
}
/**
* Same as {@link #seekToNewSource(long)} except that it does not exclude
* the current datanode and might connect to the same node.
*/
private synchronized boolean seekToBlockSource(long targetPos)
throws IOException {
currentNode = blockSeekTo(targetPos);
return true;
}
/**
* Seek to given position on a node other than the current node. If
* a node other than the current node is found, then returns true.
* If another node could not be found, then returns false.
*/
@Override
public synchronized boolean seekToNewSource(long targetPos) throws IOException {
boolean markedDead = deadNodes.containsKey(currentNode);
addToDeadNodes(currentNode);
DatanodeInfo oldNode = currentNode;
DatanodeInfo newNode = blockSeekTo(targetPos);
if (!markedDead) {
/* remove it from deadNodes. blockSeekTo could have cleared
* deadNodes and added currentNode again. Thats ok. */
deadNodes.remove(oldNode);
}
if (!oldNode.getStorageID().equals(newNode.getStorageID())) {
currentNode = newNode;
return true;
} else {
return false;
}
}
/**
*/
@Override
public synchronized long getPos() throws IOException {
return pos;
}
/**
*/
@Override
public synchronized int available() throws IOException {
if (closed) {
throw new IOException("Stream closed");
}
return (int) (getFileLength() - pos);
}
/**
* We definitely don't support marks
*/
@Override
public boolean markSupported() {
return false;
}
@Override
public void mark(int readLimit) {
}
@Override
public void reset() throws IOException {
throw new IOException("Mark/reset not supported");
}
}
static class DFSDataInputStream extends FSDataInputStream {
DFSDataInputStream(DFSInputStream in)
throws IOException {
super(in);
}
/**
* Returns the datanode from which the stream is currently reading.
*/
public DatanodeInfo getCurrentDatanode() {
return ((DFSInputStream)in).getCurrentDatanode();
}
/**
* Returns the block containing the target position.
*/
public Block getCurrentBlock() {
return ((DFSInputStream)in).getCurrentBlock();
}
/**
* Return collection of blocks that has already been located.
*/
synchronized List<LocatedBlock> getAllBlocks() throws IOException {
return ((DFSInputStream)in).getAllBlocks();
}
@Override
public boolean isUnderConstruction() throws IOException {
return ((DFSInputStream)in).isUnderConstruction();
}
}
/****************************************************************
* 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 dataQueue. The DataStreamer thread picks up
* packets from the dataQueue, sends it to the first datanode in
* the pipeline and moves it from the dataQueue to the ackQueue.
* The ResponseProcessor receives acks from the datanodes. When an
* successful ack for a packet is received from all datanodes, the
* ResponseProcessor removes the corresponding packet from the
* ackQueue.
*
* In case of error, all outstanding packets and moved from
* ackQueue. A new pipeline is setup by eliminating the bad
* datanode from the original pipeline. The DataStreamer now
* starts sending packets from the dataQueue.
****************************************************************/
class DFSOutputStream extends FSOutputSummer implements Syncable {
private Socket s;
boolean closed = false;
private String src;
private DataOutputStream blockStream;
private DataInputStream blockReplyStream;
private Block block;
final private long blockSize;
private DataChecksum checksum;
private LinkedList<Packet> dataQueue = new LinkedList<Packet>();
private LinkedList<Packet> ackQueue = new LinkedList<Packet>();
private Packet currentPacket = null;
private int maxPackets = 80; // each packet 64K, total 5MB
// private int maxPackets = 1000; // each packet 64K, total 64MB
private DataStreamer streamer = new DataStreamer();;
private ResponseProcessor response = null;
private long currentSeqno = 0;
private long bytesCurBlock = 0; // bytes writen in current block
private int packetSize = 0; // write packet size, including the header.
private int chunksPerPacket = 0;
private DatanodeInfo[] nodes = null; // list of targets for current block
private volatile boolean hasError = false;
private volatile int errorIndex = 0;
private volatile IOException lastException = null;
private long artificialSlowdown = 0;
private long lastFlushOffset = -1; // offset when flush was invoked
private boolean persistBlocks = false; // persist blocks on namenode
private int recoveryErrorCount = 0; // number of times block recovery failed
private int maxRecoveryErrorCount = 5; // try block recovery 5 times
private volatile boolean appendChunk = false; // appending to existing partial block
private long initialFileSize = 0; // at time of file open
private void setLastException(IOException e) {
if (lastException == null) {
lastException = e;
}
}
private class Packet {
ByteBuffer buffer; // only one of buf and buffer is non-null
byte[] buf;
long seqno; // sequencenumber of buffer in block
long offsetInBlock; // offset in block
boolean lastPacketInBlock; // is this the last packet in block?
int numChunks; // number of chunks currently in packet
int maxChunks; // max chunks in packet
int dataStart;
int dataPos;
int checksumStart;
int checksumPos;
private static final long HEART_BEAT_SEQNO = -1L;
/**
* create a heartbeat packet
*/
Packet() {
this.lastPacketInBlock = false;
this.numChunks = 0;
this.offsetInBlock = 0;
this.seqno = HEART_BEAT_SEQNO;
buffer = null;
int packetSize = DataNode.PKT_HEADER_LEN + SIZE_OF_INTEGER;
buf = new byte[packetSize];
checksumStart = dataStart = packetSize;
checksumPos = checksumStart;
dataPos = dataStart;
maxChunks = 0;
}
// create a new packet
Packet(int pktSize, int chunksPerPkt, long offsetInBlock) {
this.lastPacketInBlock = false;
this.numChunks = 0;
this.offsetInBlock = offsetInBlock;
this.seqno = currentSeqno;
currentSeqno++;
buffer = null;
buf = new byte[pktSize];
checksumStart = DataNode.PKT_HEADER_LEN + SIZE_OF_INTEGER;
checksumPos = checksumStart;
dataStart = checksumStart + chunksPerPkt * checksum.getChecksumSize();
dataPos = dataStart;
maxChunks = chunksPerPkt;
}
void writeData(byte[] inarray, int off, int len) {
if ( dataPos + len > buf.length) {
throw new BufferOverflowException();
}
System.arraycopy(inarray, off, buf, dataPos, len);
dataPos += len;
}
void writeChecksum(byte[] inarray, int off, int len) {
if (checksumPos + len > dataStart) {
throw new BufferOverflowException();
}
System.arraycopy(inarray, off, buf, checksumPos, len);
checksumPos += len;
}
/**
* Returns ByteBuffer that contains one full packet, including header.
*/
ByteBuffer getBuffer() {
/* Once this is called, no more data can be added to the packet.
* setting 'buf' to null ensures that.
* This is called only when the packet is ready to be sent.
*/
if (buffer != null) {
return buffer;
}
//prepare the header and close any gap between checksum and data.
int dataLen = dataPos - dataStart;
int checksumLen = checksumPos - checksumStart;
if (checksumPos != dataStart) {
/* move the checksum to cover the gap.
* This can happen for the last packet.
*/
System.arraycopy(buf, checksumStart, buf,
dataStart - checksumLen , checksumLen);
}
int pktLen = SIZE_OF_INTEGER + dataLen + checksumLen;
//normally dataStart == checksumPos, i.e., offset is zero.
buffer = ByteBuffer.wrap(buf, dataStart - checksumPos,
DataNode.PKT_HEADER_LEN + pktLen);
buf = null;
buffer.mark();
/* write the header and data length.
* The format is described in comment before DataNode.BlockSender
*/
buffer.putInt(pktLen); // pktSize
buffer.putLong(offsetInBlock);
buffer.putLong(seqno);
buffer.put((byte) ((lastPacketInBlock) ? 1 : 0));
//end of pkt header
buffer.putInt(dataLen); // actual data length, excluding checksum.
buffer.reset();
return buffer;
}
/**
* Check if this packet is a heart beat packet
* @return true if the sequence number is HEART_BEAT_SEQNO
*/
private boolean isHeartbeatPacket() {
return seqno == HEART_BEAT_SEQNO;
}
}
/** Decide if the write pipeline supports bidirectional heartbeat or not */
private boolean supportClientHeartbeat() throws IOException {
return getDataTransferProtocolVersion() >=
DataTransferProtocol.CLIENT_HEARTBEAT_VERSION;
}
//
// The DataStreamer class is responsible for sending data packets to the
// datanodes in the pipeline. It retrieves a new blockid and block locations
// from the namenode, and starts streaming packets to the pipeline of
// Datanodes. Every packet has a sequence number associated with
// it. When all the packets for a block are sent out and acks for each
// if them are received, the DataStreamer closes the current block.
//
private class DataStreamer extends Daemon {
private volatile boolean closed = false;
private long lastPacket;
private boolean doSleep;
DataStreamer() throws IOException {
// explicitly invoke RPC so avoiding RPC in waitForWork
// that might cause timeout
getDataTransferProtocolVersion();
}
private void waitForWork() throws IOException {
if ( supportClientHeartbeat() ) { // send heart beat
long now = System.currentTimeMillis();
while ((!closed && !hasError && clientRunning
&& dataQueue.size() == 0 &&
(blockStream == null || (
blockStream != null && now - lastPacket < timeoutValue/2)))
|| doSleep) {
long timeout = timeoutValue/2 - (now-lastPacket);
timeout = timeout <= 0 ? 1000 : timeout;
try {
dataQueue.wait(timeout);
now = System.currentTimeMillis();
} catch (InterruptedException e) {
}
doSleep = false;
}
} else { // no sending heart beat
while ((!closed && !hasError && clientRunning
&& dataQueue.size() == 0) || doSleep) {
try {
dataQueue.wait(1000);
} catch (InterruptedException e) {
}
doSleep = false;
}
}
}
public void run() {
while (!closed && clientRunning) {
// if the Responder encountered an error, shutdown Responder
if (hasError && response != null) {
try {
response.close();
response.join();
response = null;
} catch (InterruptedException e) {
}
}
Packet one = null;
synchronized (dataQueue) {
// process IO errors if any
doSleep = processDatanodeError(hasError, false);
try {
// wait for a packet to be sent.
waitForWork();
if (closed || hasError || !clientRunning) {
continue;
}
// get packet to be sent.
if (dataQueue.isEmpty()) {
one = new Packet(); // heartbeat packet
} else {
one = dataQueue.getFirst(); // regular data packet
}
long offsetInBlock = one.offsetInBlock;
// get new block from namenode.
if (blockStream == null) {
LOG.debug("Allocating new block");
nodes = nextBlockOutputStream(src);
this.setName("DataStreamer for file " + src +
" block " + block);
response = new ResponseProcessor(nodes);
response.start();
}
if (offsetInBlock >= blockSize) {
throw new IOException("BlockSize " + blockSize +
" is smaller than data size. " +
" Offset of packet in block " +
offsetInBlock +
" Aborting file " + src);
}
ByteBuffer buf = one.getBuffer();
// move packet from dataQueue to ackQueue
if (!one.isHeartbeatPacket()) {
dataQueue.removeFirst();
dataQueue.notifyAll();
synchronized (ackQueue) {
ackQueue.addLast(one);
ackQueue.notifyAll();
}
}
// write out data to remote datanode
blockStream.write(buf.array(), buf.position(), buf.remaining());
if (one.lastPacketInBlock) {
blockStream.writeInt(0); // indicate end-of-block
}
blockStream.flush();
lastPacket = System.currentTimeMillis();
if (LOG.isDebugEnabled()) {
LOG.debug("DataStreamer block " + block +
" wrote packet seqno:" + one.seqno +
" size:" + buf.remaining() +
" offsetInBlock:" + one.offsetInBlock +
" lastPacketInBlock:" + one.lastPacketInBlock);
}
} catch (Throwable e) {
LOG.warn("DataStreamer Exception: " +
StringUtils.stringifyException(e));
if (e instanceof IOException) {
setLastException((IOException)e);
}
hasError = true;
}
}
if (closed || hasError || !clientRunning) {
continue;
}
// Is this block full?
if (one.lastPacketInBlock) {
synchronized (ackQueue) {
while (!hasError && ackQueue.size() != 0 && clientRunning) {
try {
ackQueue.wait(); // wait for acks to arrive from datanodes
} catch (InterruptedException e) {
}
}
}
LOG.debug("Closing old block " + block);
this.setName("DataStreamer for file " + src);
response.close(); // ignore all errors in Response
try {
response.join();
response = null;
} catch (InterruptedException e) {
}
if (closed || hasError || !clientRunning) {
continue;
}
synchronized (dataQueue) {
try {
blockStream.close();
blockReplyStream.close();
} catch (IOException e) {
}
nodes = null;
response = null;
blockStream = null;
blockReplyStream = null;
}
}
if (progress != null) { progress.progress(); }
// This is used by unit test to trigger race conditions.
if (artificialSlowdown != 0 && clientRunning) {
try {
Thread.sleep(artificialSlowdown);
} catch (InterruptedException e) {}
}
}
}
// shutdown thread
void close() {
closed = true;
synchronized (dataQueue) {
dataQueue.notifyAll();
}
synchronized (ackQueue) {
ackQueue.notifyAll();
}
this.interrupt();
}
}
//
// Processes reponses from the datanodes. A packet is removed
// from the ackQueue when its response arrives.
//
private class ResponseProcessor extends Thread {
private volatile boolean closed = false;
private DatanodeInfo[] targets = null;
private boolean lastPacketInBlock = false;
ResponseProcessor (DatanodeInfo[] targets) {
this.targets = targets;
}
public void run() {
this.setName("ResponseProcessor for block " + block);
while (!closed && clientRunning && !lastPacketInBlock) {
// process responses from datanodes.
try {
// verify seqno from datanode
long seqno = blockReplyStream.readLong();
LOG.debug("DFSClient received ack for seqno " + seqno);
if (seqno == Packet.HEART_BEAT_SEQNO && !supportClientHeartbeat()) {
continue;
}
// regular ack
// processes response status from all datanodes.
for (int i = 0; i < targets.length && clientRunning; i++) {
short reply = blockReplyStream.readShort();
if (reply != DataTransferProtocol.OP_STATUS_SUCCESS) {
errorIndex = i; // first bad datanode
throw new IOException("Bad response " + reply +
" for block " + block +
" from datanode " +
targets[i].getName());
}
}
assert seqno != -2 :
"Ack for unkown seqno should be a failed ack!";
if (seqno == Packet.HEART_BEAT_SEQNO) { // a heartbeat ack
assert supportClientHeartbeat();
continue;
}
Packet one = null;
synchronized (ackQueue) {
one = ackQueue.getFirst();
}
if (one.seqno != seqno) {
throw new IOException("Responseprocessor: Expecting seqno " +
" for block " + block +
one.seqno + " but received " + seqno);
}
lastPacketInBlock = one.lastPacketInBlock;
synchronized (ackQueue) {
ackQueue.removeFirst();
ackQueue.notifyAll();
}
} catch (Exception e) {
if (!closed) {
hasError = true;
if (e instanceof IOException) {
setLastException((IOException)e);
}
LOG.warn("DFSOutputStream ResponseProcessor exception " +
" for block " + block +
StringUtils.stringifyException(e));
closed = true;
}
}
synchronized (dataQueue) {
dataQueue.notifyAll();
}
synchronized (ackQueue) {
ackQueue.notifyAll();
}
}
}
void close() {
closed = true;
this.interrupt();
}
}
// If this stream has encountered any errors so far, shutdown
// threads and mark stream as closed. Returns true if we should
// sleep for a while after returning from this call.
//
private boolean processDatanodeError(boolean hasError, boolean isAppend) {
if (!hasError) {
return false;
}
if (response != null) {
LOG.info("Error Recovery for block " + block +
" waiting for responder to exit. ");
return true;
}
if (errorIndex >= 0) {
LOG.warn("Error Recovery for block " + block
+ " bad datanode[" + errorIndex + "] "
+ (nodes == null? "nodes == null": nodes[errorIndex].getName()));
}
if (blockStream != null) {
try {
blockStream.close();
blockReplyStream.close();
} catch (IOException e) {
}
}
blockStream = null;
blockReplyStream = null;
// move packets from ack queue to front of the data queue
synchronized (ackQueue) {
dataQueue.addAll(0, ackQueue);
ackQueue.clear();
}
boolean success = false;
while (!success && clientRunning) {
DatanodeInfo[] newnodes = null;
if (nodes == null) {
String msg = "Could not get block locations. " +
"Source file \"" + src
+ "\" - Aborting...";
LOG.warn(msg);
setLastException(new IOException(msg));
closed = true;
if (streamer != null) streamer.close();
return false;
}
StringBuilder pipelineMsg = new StringBuilder();
for (int j = 0; j < nodes.length; j++) {
pipelineMsg.append(nodes[j].getName());
if (j < nodes.length - 1) {
pipelineMsg.append(", ");
}
}
// remove bad datanode from list of datanodes.
// If errorIndex was not set (i.e. appends), then do not remove
// any datanodes
//
if (errorIndex < 0) {
newnodes = nodes;
} else {
if (nodes.length <= 1) {
lastException = new IOException("All datanodes " + pipelineMsg +
" are bad. Aborting...");
closed = true;
if (streamer != null) streamer.close();
return false;
}
LOG.warn("Error Recovery for block " + block +
" in pipeline " + pipelineMsg +
": bad datanode " + nodes[errorIndex].getName());
newnodes = new DatanodeInfo[nodes.length-1];
System.arraycopy(nodes, 0, newnodes, 0, errorIndex);
System.arraycopy(nodes, errorIndex+1, newnodes, errorIndex,
newnodes.length-errorIndex);
}
// Tell the primary datanode to do error recovery
// by stamping appropriate generation stamps.
//
LocatedBlock newBlock = null;
ClientDatanodeProtocol primary = null;
DatanodeInfo primaryNode = null;
try {
// Pick the "least" datanode as the primary datanode to avoid deadlock.
primaryNode = Collections.min(Arrays.asList(newnodes));
primary = createClientDatanodeProtocolProxy(primaryNode, conf);
newBlock = primary.recoverBlock(block, isAppend, newnodes);
} catch (IOException e) {
recoveryErrorCount++;
if (recoveryErrorCount > maxRecoveryErrorCount) {
if (nodes.length > 1) {
// if the primary datanode failed, remove it from the list.
// The original bad datanode is left in the list because it is
// conservative to remove only one datanode in one iteration.
for (int j = 0; j < nodes.length; j++) {
if (nodes[j].equals(primaryNode)) {
errorIndex = j; // forget original bad node.
}
}
// remove primary node from list
newnodes = new DatanodeInfo[nodes.length-1];
System.arraycopy(nodes, 0, newnodes, 0, errorIndex);
System.arraycopy(nodes, errorIndex+1, newnodes, errorIndex,
newnodes.length-errorIndex);
nodes = newnodes;
LOG.warn("Error Recovery for block " + block + " failed " +
" because recovery from primary datanode " +
primaryNode + " failed " + recoveryErrorCount +
" times. " + " Pipeline was " + pipelineMsg +
". Marking primary datanode as bad.");
recoveryErrorCount = 0;
errorIndex = -1;
return true; // sleep when we return from here
}
String emsg = "Error Recovery for block " + block + " failed " +
" because recovery from primary datanode " +
primaryNode + " failed " + recoveryErrorCount +
" times. " + " Pipeline was " + pipelineMsg +
". Aborting...";
LOG.warn(emsg);
lastException = new IOException(emsg);
closed = true;
if (streamer != null) streamer.close();
return false; // abort with IOexception
}
LOG.warn("Error Recovery for block " + block + " failed " +
" because recovery from primary datanode " +
primaryNode + " failed " + recoveryErrorCount +
" times. " + " Pipeline was " + pipelineMsg +
". Will retry...");
return true; // sleep when we return from here
} finally {
RPC.stopProxy(primary);
}
recoveryErrorCount = 0; // block recovery successful
// If the block recovery generated a new generation stamp, use that
// from now on. Also, setup new pipeline
//
if (newBlock != null) {
block = newBlock.getBlock();
nodes = newBlock.getLocations();
}
this.hasError = false;
lastException = null;
errorIndex = 0;
success = createBlockOutputStream(nodes, clientName, true);
}
response = new ResponseProcessor(nodes);
response.start();
return false; // do not sleep, continue processing
}
private void isClosed() throws IOException {
if (closed && lastException != null) {
throw lastException;
}
}
//
// returns the list of targets, if any, that is being currently used.
//
DatanodeInfo[] getPipeline() {
synchronized (dataQueue) {
if (nodes == null) {
return null;
}
DatanodeInfo[] value = new DatanodeInfo[nodes.length];
for (int i = 0; i < nodes.length; i++) {
value[i] = nodes[i];
}
return value;
}
}
private Progressable progress;
private DFSOutputStream(String src, long blockSize, Progressable progress,
int bytesPerChecksum) throws IOException {
super(new CRC32(), bytesPerChecksum, 4);
this.src = src;
this.blockSize = blockSize;
this.progress = progress;
if (progress != null) {
LOG.debug("Set non-null progress callback on DFSOutputStream "+src);
}
if ( bytesPerChecksum < 1 || blockSize % bytesPerChecksum != 0) {
throw new IOException("io.bytes.per.checksum(" + bytesPerChecksum +
") and blockSize(" + blockSize +
") do not match. " + "blockSize should be a " +
"multiple of io.bytes.per.checksum");
}
checksum = DataChecksum.newDataChecksum(DataChecksum.CHECKSUM_CRC32,
bytesPerChecksum);
}
/**
* Create a new output stream to the given DataNode.
* @see ClientProtocol#create(String, FsPermission, String, boolean, short, long)
*/
DFSOutputStream(String src, FsPermission masked, boolean overwrite,
short replication, long blockSize, Progressable progress,
int buffersize, int bytesPerChecksum) throws IOException {
this(src, blockSize, progress, bytesPerChecksum);
computePacketChunkSize(writePacketSize, bytesPerChecksum);
try {
namenode.create(
src, masked, clientName, overwrite, replication, blockSize);
} catch(RemoteException re) {
throw re.unwrapRemoteException(AccessControlException.class,
NSQuotaExceededException.class,
DSQuotaExceededException.class);
}
streamer.start();
}
/**
* Create a new output stream to the given DataNode.
* @see ClientProtocol#create(String, FsPermission, String, boolean, short, long)
*/
DFSOutputStream(String src, int buffersize, Progressable progress,
LocatedBlock lastBlock, FileStatus stat,
int bytesPerChecksum) throws IOException {
this(src, stat.getBlockSize(), progress, bytesPerChecksum);
initialFileSize = stat.getLen(); // length of file when opened
//
// The last partial block of the file has to be filled.
//
if (lastBlock != null) {
block = lastBlock.getBlock();
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.");
}
// indicate that we are appending to an existing block
bytesCurBlock = lastBlock.getBlockSize();
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);
resetChecksumChunk(freeInCksum);
this.appendChunk = 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(writePacketSize, freeInLastBlock),
bytesPerChecksum);
}
// setup pipeline to append to the last block XXX retries??
nodes = lastBlock.getLocations();
errorIndex = -1; // no errors yet.
if (nodes.length < 1) {
throw new IOException("Unable to retrieve blocks locations " +
" for last block " + block +
"of file " + src);
}
processDatanodeError(true, true);
streamer.start();
}
else {
computePacketChunkSize(writePacketSize, bytesPerChecksum);
streamer.start();
}
}
private void computePacketChunkSize(int psize, int csize) {
int chunkSize = csize + checksum.getChecksumSize();
int n = DataNode.PKT_HEADER_LEN + SIZE_OF_INTEGER;
chunksPerPacket = Math.max((psize - n + chunkSize-1)/chunkSize, 1);
packetSize = n + chunkSize*chunksPerPacket;
if (LOG.isDebugEnabled()) {
LOG.debug("computePacketChunkSize: src=" + src +
", chunkSize=" + chunkSize +
", chunksPerPacket=" + chunksPerPacket +
", packetSize=" + packetSize);
}
}
/**
* Open a DataOutputStream to a DataNode so that it can be written to.
* This happens when a file is created and each time a new block is allocated.
* Must get block ID and the IDs of the destinations from the namenode.
* Returns the list of target datanodes.
*/
private DatanodeInfo[] nextBlockOutputStream(String client) throws IOException {
LocatedBlock lb = null;
boolean retry = false;
DatanodeInfo[] nodes;
int count = conf.getInt("dfs.client.block.write.retries", 3);
boolean success;
do {
hasError = false;
lastException = null;
errorIndex = 0;
retry = false;
nodes = null;
success = false;
long startTime = System.currentTimeMillis();
lb = locateFollowingBlock(startTime);
block = lb.getBlock();
nodes = lb.getLocations();
//
// Connect to first DataNode in the list.
//
success = createBlockOutputStream(nodes, clientName, false);
if (!success) {
LOG.info("Abandoning block " + block);
namenode.abandonBlock(block, src, clientName);
// Connection failed. Let's wait a little bit and retry
retry = true;
try {
if (System.currentTimeMillis() - startTime > 5000) {
LOG.info("Waiting to find target node: " + nodes[0].getName());
}
Thread.sleep(6000);
} catch (InterruptedException iex) {
}
}
} while (retry && --count >= 0);
if (!success) {
throw new IOException("Unable to create new block.");
}
return nodes;
}
// connects to the first datanode in the pipeline
// Returns true if success, otherwise return failure.
//
private boolean createBlockOutputStream(DatanodeInfo[] nodes, String client,
boolean recoveryFlag) {
String firstBadLink = "";
if (LOG.isDebugEnabled()) {
for (int i = 0; i < nodes.length; i++) {
LOG.debug("pipeline = " + nodes[i].getName());
}
}
// persist blocks on namenode on next flush
persistBlocks = true;
boolean result = false;
try {
LOG.debug("Connecting to " + nodes[0].getName());
InetSocketAddress target = NetUtils.createSocketAddr(nodes[0].getName());
s = socketFactory.createSocket();
int timeoutValue = 3000 * nodes.length + socketTimeout;
NetUtils.connect(s, target, timeoutValue);
s.setSoTimeout(timeoutValue);
s.setSendBufferSize(DEFAULT_DATA_SOCKET_SIZE);
LOG.debug("Send buf size " + s.getSendBufferSize());
long writeTimeout = HdfsConstants.WRITE_TIMEOUT_EXTENSION * nodes.length +
datanodeWriteTimeout;
//
// Xmit header info to datanode
//
DataOutputStream out = new DataOutputStream(
new BufferedOutputStream(NetUtils.getOutputStream(s, writeTimeout),
DataNode.SMALL_BUFFER_SIZE));
blockReplyStream = new DataInputStream(NetUtils.getInputStream(s));
out.writeShort( getDataTransferProtocolVersion() );
out.write( DataTransferProtocol.OP_WRITE_BLOCK );
out.writeLong( block.getBlockId() );
out.writeLong( block.getGenerationStamp() );
out.writeInt( nodes.length );
out.writeBoolean( recoveryFlag ); // recovery flag
Text.writeString( out, client );
out.writeBoolean(false); // Not sending src node information
out.writeInt( nodes.length - 1 );
for (int i = 1; i < nodes.length; i++) {
nodes[i].write(out);
}
checksum.writeHeader( out );
out.flush();
// receive ack for connect
firstBadLink = Text.readString(blockReplyStream);
if (firstBadLink.length() != 0) {
throw new IOException("Bad connect ack with firstBadLink " + firstBadLink);
}
blockStream = out;
result = true; // success
} catch (IOException ie) {
LOG.info("Exception in createBlockOutputStream " + nodes[0].getName() + " " +
ie);
// find the datanode that matches
if (firstBadLink.length() != 0) {
for (int i = 0; i < nodes.length; i++) {
if (nodes[i].getName().equals(firstBadLink)) {
errorIndex = i;
break;
}
}
}
hasError = true;
setLastException(ie);
blockReplyStream = null;
result = false;
} finally {
if (!result) {
IOUtils.closeSocket(s);
s = null;
}
}
return result;
}
private LocatedBlock locateFollowingBlock(long start
) throws IOException {
int retries = conf.getInt("dfs.client.block.write.locateFollowingBlock.retries", 5);
long sleeptime = 400;
while (true) {
long localstart = System.currentTimeMillis();
while (true) {
try {
return namenode.addBlock(src, clientName);
} catch (RemoteException e) {
IOException ue =
e.unwrapRemoteException(FileNotFoundException.class,
AccessControlException.class,
NSQuotaExceededException.class,
DSQuotaExceededException.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(StringUtils.stringifyException(e));
if (System.currentTimeMillis() - localstart > 5000) {
LOG.info("Waiting for replication for "
+ (System.currentTimeMillis() - localstart) / 1000
+ " seconds");
}
try {
LOG.warn("NotReplicatedYetException sleeping " + src
+ " retries left " + retries);
Thread.sleep(sleeptime);
sleeptime *= 2;
} catch (InterruptedException ie) {
}
}
} else {
throw e;
}
}
}
}
}
// @see FSOutputSummer#writeChunk()
@Override
protected synchronized void writeChunk(byte[] b, int offset, int len, byte[] checksum)
throws IOException {
checkOpen();
isClosed();
int cklen = checksum.length;
int bytesPerChecksum = this.checksum.getBytesPerChecksum();
if (len > bytesPerChecksum) {
throw new IOException("writeChunk() buffer size is " + len +
" is larger than supported bytesPerChecksum " +
bytesPerChecksum);
}
if (checksum.length != this.checksum.getChecksumSize()) {
throw new IOException("writeChunk() checksum size is supposed to be " +
this.checksum.getChecksumSize() +
" but found to be " + checksum.length);
}
synchronized (dataQueue) {
// If queue is full, then wait till we can create enough space
while (!closed && dataQueue.size() + ackQueue.size() > maxPackets) {
try {
dataQueue.wait();
} catch (InterruptedException e) {
}
}
isClosed();
if (currentPacket == null) {
currentPacket = new Packet(packetSize, chunksPerPacket,
bytesCurBlock);
if (LOG.isDebugEnabled()) {
LOG.debug("DFSClient writeChunk allocating new packet seqno=" +
currentPacket.seqno +
", src=" + src +
", packetSize=" + packetSize +
", chunksPerPacket=" + chunksPerPacket +
", bytesCurBlock=" + bytesCurBlock);
}
}
currentPacket.writeChecksum(checksum, 0, cklen);
currentPacket.writeData(b, offset, len);
currentPacket.numChunks++;
bytesCurBlock += len;
// If packet is full, enqueue it for transmission
//
if (currentPacket.numChunks == currentPacket.maxChunks ||
bytesCurBlock == blockSize) {
if (LOG.isDebugEnabled()) {
LOG.debug("DFSClient writeChunk packet full seqno=" +
currentPacket.seqno +
", src=" + src +
", bytesCurBlock=" + bytesCurBlock +
", blockSize=" + blockSize +
", appendChunk=" + appendChunk);
}
//
// if we allocated a new packet because we encountered a block
// boundary, reset bytesCurBlock.
//
if (bytesCurBlock == blockSize) {
currentPacket.lastPacketInBlock = true;
bytesCurBlock = 0;
lastFlushOffset = -1;
}
dataQueue.addLast(currentPacket);
dataQueue.notifyAll();
currentPacket = null;
// If this was the first write after reopening a file, then the above
// write filled up any partial chunk. Tell the summer to generate full
// crc chunks from now on.
if (appendChunk) {
appendChunk = false;
resetChecksumChunk(bytesPerChecksum);
}
int psize = Math.min((int)(blockSize-bytesCurBlock), writePacketSize);
computePacketChunkSize(psize, bytesPerChecksum);
}
}
//LOG.debug("DFSClient writeChunk done length " + len +
// " checksum length " + cklen);
}
/**
* All data is written out to datanodes. It is not guaranteed
* that data has been flushed to persistent store on the
* datanode. Block allocations are persisted on namenode.
*/
public synchronized void sync() throws IOException {
try {
/* Record current blockOffset. This might be changed inside
* flushBuffer() where a partial checksum chunk might be flushed.
* After the flush, reset the bytesCurBlock back to its previous value,
* any partial checksum chunk will be sent now and in next packet.
*/
long saveOffset = bytesCurBlock;
// flush checksum buffer, but keep checksum buffer intact
flushBuffer(true);
LOG.debug("DFSClient flush() : saveOffset " + saveOffset +
" bytesCurBlock " + bytesCurBlock +
" lastFlushOffset " + lastFlushOffset);
// Flush only if we haven't already flushed till this offset.
if (lastFlushOffset != bytesCurBlock) {
// record the valid offset of this flush
lastFlushOffset = bytesCurBlock;
// wait for all packets to be sent and acknowledged
flushInternal();
} else {
// just discard the current packet since it is already been sent.
currentPacket = null;
}
// Restore state of stream. Record the last flush offset
// of the last full chunk that was flushed.
//
bytesCurBlock = saveOffset;
// If any new blocks were allocated since the last flush,
// then persist block locations on namenode.
//
if (persistBlocks) {
namenode.fsync(src, clientName);
persistBlocks = false;
}
} catch (IOException e) {
lastException = new IOException("IOException flush:" + e);
closed = true;
closeThreads();
throw e;
}
}
/**
* Waits till all existing data is flushed and confirmations
* received from datanodes.
*/
private synchronized void flushInternal() throws IOException {
checkOpen();
isClosed();
while (!closed) {
synchronized (dataQueue) {
isClosed();
//
// If there is data in the current buffer, send it across
//
if (currentPacket != null) {
dataQueue.addLast(currentPacket);
dataQueue.notifyAll();
currentPacket = null;
}
// wait for all buffers to be flushed to datanodes
if (!closed && dataQueue.size() != 0) {
try {
dataQueue.wait();
} catch (InterruptedException e) {
}
continue;
}
}
// wait for all acks to be received back from datanodes
synchronized (ackQueue) {
if (!closed && ackQueue.size() != 0) {
try {
ackQueue.wait();
} catch (InterruptedException e) {
}
continue;
}
}
// acquire both the locks and verify that we are
// *really done*. In the case of error recovery,
// packets might move back from ackQueue to dataQueue.
//
synchronized (dataQueue) {
synchronized (ackQueue) {
if (dataQueue.size() + ackQueue.size() == 0) {
break; // we are done
}
}
}
}
}
/**
* Closes this output stream and releases any system
* resources associated with this stream.
*/
@Override
public void close() throws IOException {
if (closed) {
IOException e = lastException;
if (e == null)
return;
else
throw e;
}
closeInternal();
leasechecker.remove(src);
if (s != null) {
s.close();
s = null;
}
}
/**
* Harsh abort method that should only be used from tests - this
* is in order to prevent pipeline recovery when eg a DN shuts down.
*/
void abortForTests() throws IOException {
streamer.close();
response.close();
closed = true;
}
/**
* Aborts this output stream and releases any system
* resources associated with this stream.
*/
synchronized void abort() throws IOException {
if (closed) {
return;
}
setLastException(new IOException("Lease timeout of " +
(hdfsTimeout/1000) + " seconds expired."));
closeThreads();
}
// shutdown datastreamer and responseprocessor threads.
private void closeThreads() throws IOException {
try {
if (streamer != null) {
streamer.close();
streamer.join();
}
// shutdown response after streamer has exited.
if (response != null) {
response.close();
response.join();
response = null;
}
} catch (InterruptedException e) {
throw new IOException("Failed to shutdown response thread");
}
}
/**
* Closes this output stream and releases any system
* resources associated with this stream.
*/
private synchronized void closeInternal() throws IOException {
checkOpen();
isClosed();
try {
flushBuffer(); // flush from all upper layers
// Mark that this packet is the last packet in block.
// If there are no outstanding packets and the last packet
// was not the last one in the current block, then create a
// packet with empty payload.
synchronized (dataQueue) {
if (currentPacket == null && bytesCurBlock != 0) {
currentPacket = new Packet(packetSize, chunksPerPacket,
bytesCurBlock);
}
if (currentPacket != null) {
currentPacket.lastPacketInBlock = true;
}
}
flushInternal(); // flush all data to Datanodes
isClosed(); // check to see if flushInternal had any exceptions
closed = true; // allow closeThreads() to showdown threads
closeThreads();
synchronized (dataQueue) {
if (blockStream != null) {
blockStream.writeInt(0); // indicate end-of-block to datanode
blockStream.close();
blockReplyStream.close();
}
if (s != null) {
s.close();
s = null;
}
}
streamer = null;
blockStream = null;
blockReplyStream = null;
long localstart = System.currentTimeMillis();
boolean fileComplete = false;
while (!fileComplete) {
fileComplete = namenode.complete(src, clientName);
if (!fileComplete) {
if (!clientRunning ||
(hdfsTimeout > 0 &&
localstart + hdfsTimeout < System.currentTimeMillis())) {
String msg = "Unable to close file because dfsclient " +
" was unable to contact the HDFS servers." +
" clientRunning " + clientRunning +
" hdfsTimeout " + hdfsTimeout;
LOG.info(msg);
throw new IOException(msg);
}
try {
Thread.sleep(400);
if (System.currentTimeMillis() - localstart > 5000) {
LOG.info("Could not complete file " + src + " retrying...");
}
} catch (InterruptedException ie) {
}
}
}
} finally {
closed = true;
}
}
void setArtificialSlowdown(long period) {
artificialSlowdown = period;
}
synchronized void setChunksPerPacket(int value) {
chunksPerPacket = Math.min(chunksPerPacket, value);
packetSize = DataNode.PKT_HEADER_LEN + SIZE_OF_INTEGER +
(checksum.getBytesPerChecksum() +
checksum.getChecksumSize()) * chunksPerPacket;
}
synchronized void setTestFilename(String newname) {
src = newname;
}
/**
* Returns the size of a file as it was when this stream was opened
*/
long getInitialLen() {
return initialFileSize;
}
}
void reportChecksumFailure(String file, Block blk, DatanodeInfo dn) {
DatanodeInfo [] dnArr = { dn };
LocatedBlock [] lblocks = { new LocatedBlock(blk, dnArr) };
reportChecksumFailure(file, lblocks);
}
// just reports checksum failure and ignores any exception during the report.
void reportChecksumFailure(String file, LocatedBlock lblocks[]) {
try {
reportBadBlocks(lblocks);
} catch (IOException ie) {
LOG.info("Found corruption while reading " + file
+ ". Error repairing corrupt blocks. Bad blocks remain. "
+ StringUtils.stringifyException(ie));
}
}
/**
* Get the data transfer protocol version supported in the cluster
* assuming all the datanodes have the same version.
*
* @return the data transfer protocol version supported in the cluster
*/
int getDataTransferProtocolVersion() throws IOException {
synchronized (dataTransferVersion) {
if (dataTransferVersion == -1) {
// Get the version number from NN
try {
dataTransferVersion = namenode.getDataTransferProtocolVersion();
} catch (RemoteException re) {
IOException ioe = re.unwrapRemoteException(IOException.class);
if (ioe.getMessage().startsWith(IOException.class.getName() + ": " +
NoSuchMethodException.class.getName())) {
dataTransferVersion = 14; // last version not supportting this RPC
} else {
throw ioe;
}
}
}
return dataTransferVersion;
}
}
/** {@inheritDoc} */
public String toString() {
return getClass().getSimpleName() + "[clientName=" + clientName
+ ", ugi=" + ugi + "]";
}
}