/**
* 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.server.namenode;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.DataInput;
import java.io.DataInputStream;
import java.io.DataOutput;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.net.URI;
import java.nio.ByteBuffer;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Random;
import java.util.Set;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.permission.FsPermission;
import org.apache.hadoop.fs.permission.PermissionStatus;
import org.apache.hadoop.hdfs.DFSUtil;
import org.apache.hadoop.hdfs.DeprecatedUTF8;
import org.apache.hadoop.hdfs.protocol.Block;
import org.apache.hadoop.hdfs.protocol.DatanodeID;
import org.apache.hadoop.hdfs.protocol.FSConstants;
import org.apache.hadoop.hdfs.server.common.GenerationStamp;
import org.apache.hadoop.hdfs.server.common.InconsistentFSStateException;
import org.apache.hadoop.hdfs.server.common.Storage;
import org.apache.hadoop.hdfs.server.common.StorageInfo;
import org.apache.hadoop.hdfs.server.common.UpgradeManager;
import org.apache.hadoop.hdfs.server.common.Util;
import org.apache.hadoop.hdfs.server.common.HdfsConstants.BlockUCState;
import org.apache.hadoop.hdfs.server.common.HdfsConstants.NamenodeRole;
import org.apache.hadoop.hdfs.server.common.HdfsConstants.NodeType;
import org.apache.hadoop.hdfs.server.common.HdfsConstants.StartupOption;
import org.apache.hadoop.hdfs.server.namenode.JournalStream.JournalType;
import org.apache.hadoop.hdfs.server.protocol.CheckpointCommand;
import org.apache.hadoop.hdfs.server.protocol.NamenodeCommand;
import org.apache.hadoop.hdfs.server.protocol.NamenodeProtocol;
import org.apache.hadoop.hdfs.server.protocol.NamenodeRegistration;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.hdfs.DFSConfigKeys;
/**
* FSImage handles checkpointing and logging of the namespace edits.
*
*/
@InterfaceAudience.Private
@InterfaceStability.Evolving
public class FSImage extends Storage {
private static final SimpleDateFormat DATE_FORM =
new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
//
// The filenames used for storing the images
//
enum NameNodeFile {
IMAGE ("fsimage"),
TIME ("fstime"),
EDITS ("edits"),
IMAGE_NEW ("fsimage.ckpt"),
EDITS_NEW ("edits.new");
private String fileName = null;
private NameNodeFile(String name) {this.fileName = name;}
String getName() {return fileName;}
}
// checkpoint states
enum CheckpointStates{START, ROLLED_EDITS, UPLOAD_START, UPLOAD_DONE; }
/**
* Implementation of StorageDirType specific to namenode storage
* A Storage directory could be of type IMAGE which stores only fsimage,
* or of type EDITS which stores edits or of type IMAGE_AND_EDITS which
* stores both fsimage and edits.
*/
static enum NameNodeDirType implements StorageDirType {
UNDEFINED,
IMAGE,
EDITS,
IMAGE_AND_EDITS;
public StorageDirType getStorageDirType() {
return this;
}
public boolean isOfType(StorageDirType type) {
if ((this == IMAGE_AND_EDITS) && (type == IMAGE || type == EDITS))
return true;
return this == type;
}
}
protected FSNamesystem namesystem = null;
protected long checkpointTime = -1L; // The age of the image
protected FSEditLog editLog = null;
private boolean isUpgradeFinalized = false;
/**
* flag that controls if we try to restore failed storages
*/
private boolean restoreFailedStorage = false;
/**
* list of failed (and thus removed) storages
*/
protected List<StorageDirectory> removedStorageDirs = new ArrayList<StorageDirectory>();
/**
* URIs for importing an image from a checkpoint. In the default case,
* URIs will represent directories.
*/
private Collection<URI> checkpointDirs;
private Collection<URI> checkpointEditsDirs;
/**
* Can fs-image be rolled?
*/
volatile protected CheckpointStates ckptState = FSImage.CheckpointStates.START;
/**
* Used for saving the image to disk
*/
static private final FsPermission FILE_PERM = new FsPermission((short)0);
static private final byte[] PATH_SEPARATOR = DFSUtil.string2Bytes(Path.SEPARATOR);
/**
*/
FSImage() {
this((FSNamesystem)null);
}
FSImage(FSNamesystem ns) {
super(NodeType.NAME_NODE);
this.editLog = new FSEditLog(this);
setFSNamesystem(ns);
}
/**
* @throws IOException
*/
FSImage(Collection<URI> fsDirs, Collection<URI> fsEditsDirs)
throws IOException {
this();
setStorageDirectories(fsDirs, fsEditsDirs);
}
public FSImage(StorageInfo storageInfo) {
super(NodeType.NAME_NODE, storageInfo);
}
/**
* Represents an Image (image and edit file).
* @throws IOException
*/
FSImage(URI imageDir) throws IOException {
this();
ArrayList<URI> dirs = new ArrayList<URI>(1);
ArrayList<URI> editsDirs = new ArrayList<URI>(1);
dirs.add(imageDir);
editsDirs.add(imageDir);
setStorageDirectories(dirs, editsDirs);
}
protected FSNamesystem getFSNamesystem() {
return namesystem;
}
void setFSNamesystem(FSNamesystem ns) {
namesystem = ns;
}
public void setRestoreFailedStorage(boolean val) {
LOG.info("set restore failed storage to " + val);
restoreFailedStorage=val;
}
public boolean getRestoreFailedStorage() {
return restoreFailedStorage;
}
void setStorageDirectories(Collection<URI> fsNameDirs,
Collection<URI> fsEditsDirs) throws IOException {
this.storageDirs = new ArrayList<StorageDirectory>();
this.removedStorageDirs = new ArrayList<StorageDirectory>();
// Add all name dirs with appropriate NameNodeDirType
for (URI dirName : fsNameDirs) {
checkSchemeConsistency(dirName);
boolean isAlsoEdits = false;
for (URI editsDirName : fsEditsDirs) {
if (editsDirName.compareTo(dirName) == 0) {
isAlsoEdits = true;
fsEditsDirs.remove(editsDirName);
break;
}
}
NameNodeDirType dirType = (isAlsoEdits) ?
NameNodeDirType.IMAGE_AND_EDITS :
NameNodeDirType.IMAGE;
// Add to the list of storage directories, only if the
// URI is of type file://
if(dirName.getScheme().compareTo(JournalType.FILE.name().toLowerCase())
== 0){
this.addStorageDir(new StorageDirectory(new File(dirName.getPath()),
dirType));
}
}
// Add edits dirs if they are different from name dirs
for (URI dirName : fsEditsDirs) {
checkSchemeConsistency(dirName);
// Add to the list of storage directories, only if the
// URI is of type file://
if(dirName.getScheme().compareTo(JournalType.FILE.name().toLowerCase())
== 0)
this.addStorageDir(new StorageDirectory(new File(dirName.getPath()),
NameNodeDirType.EDITS));
}
}
/*
* Checks the consistency of a URI, in particular if the scheme
* is specified and is supported by a concrete implementation
*/
static void checkSchemeConsistency(URI u) throws IOException {
String scheme = u.getScheme();
// the URI should have a proper scheme
if(scheme == null)
throw new IOException("Undefined scheme for " + u);
else {
try {
// the scheme should be enumerated as JournalType
JournalType.valueOf(scheme.toUpperCase());
} catch (IllegalArgumentException iae){
throw new IOException("Unknown scheme " + scheme +
". It should correspond to a JournalType enumeration value");
}
}
};
void setCheckpointDirectories(Collection<URI> dirs,
Collection<URI> editsDirs) {
checkpointDirs = dirs;
checkpointEditsDirs = editsDirs;
}
static File getImageFile(StorageDirectory sd, NameNodeFile type) {
return new File(sd.getCurrentDir(), type.getName());
}
List<StorageDirectory> getRemovedStorageDirs() {
return this.removedStorageDirs;
}
File getEditFile(StorageDirectory sd) {
return getImageFile(sd, NameNodeFile.EDITS);
}
File getEditNewFile(StorageDirectory sd) {
return getImageFile(sd, NameNodeFile.EDITS_NEW);
}
Collection<File> getFiles(NameNodeFile type, NameNodeDirType dirType) {
ArrayList<File> list = new ArrayList<File>();
Iterator<StorageDirectory> it = (dirType == null) ? dirIterator() :
dirIterator(dirType);
for ( ;it.hasNext(); ) {
list.add(getImageFile(it.next(), type));
}
return list;
}
Collection<URI> getDirectories(NameNodeDirType dirType)
throws IOException {
ArrayList<URI> list = new ArrayList<URI>();
Iterator<StorageDirectory> it = (dirType == null) ? dirIterator() :
dirIterator(dirType);
for ( ;it.hasNext(); ) {
StorageDirectory sd = it.next();
try {
list.add(Util.fileAsURI(sd.getRoot()));
} catch (IOException e) {
throw new IOException("Exception while processing " +
"StorageDirectory " + sd.getRoot(), e);
}
}
return list;
}
/**
* Retrieve current directories of type IMAGE
* @return Collection of URI representing image directories
* @throws IOException in case of URI processing error
*/
Collection<URI> getImageDirectories() throws IOException {
return getDirectories(NameNodeDirType.IMAGE);
}
/**
* Retrieve current directories of type EDITS
* @return Collection of URI representing edits directories
* @throws IOException in case of URI processing error
*/
Collection<URI> getEditsDirectories() throws IOException {
return getDirectories(NameNodeDirType.EDITS);
}
/**
* Return number of storage directories of the given type.
* @param dirType directory type
* @return number of storage directories of type dirType
*/
int getNumStorageDirs(NameNodeDirType dirType) {
if(dirType == null)
return getNumStorageDirs();
Iterator<StorageDirectory> it = dirIterator(dirType);
int numDirs = 0;
for(; it.hasNext(); it.next())
numDirs++;
return numDirs;
}
/**
* Analyze storage directories.
* Recover from previous transitions if required.
* Perform fs state transition if necessary depending on the namespace info.
* Read storage info.
*
* @param dataDirs
* @param startOpt startup option
* @throws IOException
* @return true if the image needs to be saved or false otherwise
*/
boolean recoverTransitionRead(Collection<URI> dataDirs,
Collection<URI> editsDirs,
StartupOption startOpt)
throws IOException {
assert startOpt != StartupOption.FORMAT :
"NameNode formatting should be performed before reading the image";
// none of the data dirs exist
if((dataDirs.size() == 0 || editsDirs.size() == 0)
&& startOpt != StartupOption.IMPORT)
throw new IOException(
"All specified directories are not accessible or do not exist.");
if(startOpt == StartupOption.IMPORT
&& (checkpointDirs == null || checkpointDirs.isEmpty()))
throw new IOException("Cannot import image from a checkpoint. "
+ "\"dfs.namenode.checkpoint.dir\" is not set." );
if(startOpt == StartupOption.IMPORT
&& (checkpointEditsDirs == null || checkpointEditsDirs.isEmpty()))
throw new IOException("Cannot import image from a checkpoint. "
+ "\"dfs.namenode.checkpoint.dir\" is not set." );
setStorageDirectories(dataDirs, editsDirs);
// 1. For each data directory calculate its state and
// check whether all is consistent before transitioning.
Map<StorageDirectory, StorageState> dataDirStates =
new HashMap<StorageDirectory, StorageState>();
boolean isFormatted = false;
for (Iterator<StorageDirectory> it =
dirIterator(); it.hasNext();) {
StorageDirectory sd = it.next();
StorageState curState;
try {
curState = sd.analyzeStorage(startOpt);
// sd is locked but not opened
switch(curState) {
case NON_EXISTENT:
// name-node fails if any of the configured storage dirs are missing
throw new InconsistentFSStateException(sd.getRoot(),
"storage directory does not exist or is not accessible.");
case NOT_FORMATTED:
break;
case NORMAL:
break;
default: // recovery is possible
sd.doRecover(curState);
}
if (curState != StorageState.NOT_FORMATTED
&& startOpt != StartupOption.ROLLBACK) {
sd.read(); // read and verify consistency with other directories
isFormatted = true;
}
if (startOpt == StartupOption.IMPORT && isFormatted)
// import of a checkpoint is allowed only into empty image directories
throw new IOException("Cannot import image from a checkpoint. "
+ " NameNode already contains an image in " + sd.getRoot());
} catch (IOException ioe) {
sd.unlock();
throw ioe;
}
dataDirStates.put(sd,curState);
}
if (!isFormatted && startOpt != StartupOption.ROLLBACK
&& startOpt != StartupOption.IMPORT)
throw new IOException("NameNode is not formatted.");
if (layoutVersion < LAST_PRE_UPGRADE_LAYOUT_VERSION) {
checkVersionUpgradable(layoutVersion);
}
if (startOpt != StartupOption.UPGRADE
&& layoutVersion < LAST_PRE_UPGRADE_LAYOUT_VERSION
&& layoutVersion != FSConstants.LAYOUT_VERSION)
throw new IOException(
"\nFile system image contains an old layout version " + layoutVersion
+ ".\nAn upgrade to version " + FSConstants.LAYOUT_VERSION
+ " is required.\nPlease restart NameNode with -upgrade option.");
// check whether distributed upgrade is reguired and/or should be continued
verifyDistributedUpgradeProgress(startOpt);
// 2. Format unformatted dirs.
this.checkpointTime = 0L;
for (Iterator<StorageDirectory> it =
dirIterator(); it.hasNext();) {
StorageDirectory sd = it.next();
StorageState curState = dataDirStates.get(sd);
switch(curState) {
case NON_EXISTENT:
throw new IOException(StorageState.NON_EXISTENT +
" state cannot be here");
case NOT_FORMATTED:
LOG.info("Storage directory " + sd.getRoot() + " is not formatted.");
LOG.info("Formatting ...");
sd.clearDirectory(); // create empty currrent dir
break;
default:
break;
}
}
// 3. Do transitions
switch(startOpt) {
case UPGRADE:
doUpgrade();
return false; // upgrade saved image already
case IMPORT:
doImportCheckpoint();
return false; // import checkpoint saved image already
case ROLLBACK:
doRollback();
break;
case REGULAR:
// just load the image
}
boolean needToSave = loadFSImage();
assert editLog != null : "editLog must be initialized";
if(!editLog.isOpen())
editLog.open();
return needToSave;
}
private void doUpgrade() throws IOException {
if(getDistributedUpgradeState()) {
// only distributed upgrade need to continue
// don't do version upgrade
this.loadFSImage();
initializeDistributedUpgrade();
return;
}
// Upgrade is allowed only if there are
// no previous fs states in any of the directories
for (Iterator<StorageDirectory> it =
dirIterator(); it.hasNext();) {
StorageDirectory sd = it.next();
if (sd.getPreviousDir().exists())
throw new InconsistentFSStateException(sd.getRoot(),
"previous fs state should not exist during upgrade. "
+ "Finalize or rollback first.");
}
// load the latest image
this.loadFSImage();
// Do upgrade for each directory
long oldCTime = this.getCTime();
this.cTime = FSNamesystem.now(); // generate new cTime for the state
int oldLV = this.getLayoutVersion();
this.layoutVersion = FSConstants.LAYOUT_VERSION;
this.checkpointTime = FSNamesystem.now();
for (Iterator<StorageDirectory> it =
dirIterator(); it.hasNext();) {
StorageDirectory sd = it.next();
LOG.info("Upgrading image directory " + sd.getRoot()
+ ".\n old LV = " + oldLV
+ "; old CTime = " + oldCTime
+ ".\n new LV = " + this.getLayoutVersion()
+ "; new CTime = " + this.getCTime());
File curDir = sd.getCurrentDir();
File prevDir = sd.getPreviousDir();
File tmpDir = sd.getPreviousTmp();
assert curDir.exists() : "Current directory must exist.";
assert !prevDir.exists() : "prvious directory must not exist.";
assert !tmpDir.exists() : "prvious.tmp directory must not exist.";
assert !editLog.isOpen() : "Edits log must not be open.";
// rename current to tmp
rename(curDir, tmpDir);
// save new image
saveCurrent(sd);
// rename tmp to previous
rename(tmpDir, prevDir);
isUpgradeFinalized = false;
LOG.info("Upgrade of " + sd.getRoot() + " is complete.");
}
initializeDistributedUpgrade();
editLog.open();
}
private void doRollback() throws IOException {
// Rollback is allowed only if there is
// a previous fs states in at least one of the storage directories.
// Directories that don't have previous state do not rollback
boolean canRollback = false;
FSImage prevState = new FSImage(getFSNamesystem());
prevState.layoutVersion = FSConstants.LAYOUT_VERSION;
for (Iterator<StorageDirectory> it =
dirIterator(); it.hasNext();) {
StorageDirectory sd = it.next();
File prevDir = sd.getPreviousDir();
if (!prevDir.exists()) { // use current directory then
LOG.info("Storage directory " + sd.getRoot()
+ " does not contain previous fs state.");
sd.read(); // read and verify consistency with other directories
continue;
}
StorageDirectory sdPrev = prevState.new StorageDirectory(sd.getRoot());
sdPrev.read(sdPrev.getPreviousVersionFile()); // read and verify consistency of the prev dir
canRollback = true;
}
if (!canRollback)
throw new IOException("Cannot rollback. "
+ "None of the storage directories contain previous fs state.");
// Now that we know all directories are going to be consistent
// Do rollback for each directory containing previous state
for (Iterator<StorageDirectory> it =
dirIterator(); it.hasNext();) {
StorageDirectory sd = it.next();
File prevDir = sd.getPreviousDir();
if (!prevDir.exists())
continue;
LOG.info("Rolling back storage directory " + sd.getRoot()
+ ".\n new LV = " + prevState.getLayoutVersion()
+ "; new CTime = " + prevState.getCTime());
File tmpDir = sd.getRemovedTmp();
assert !tmpDir.exists() : "removed.tmp directory must not exist.";
// rename current to tmp
File curDir = sd.getCurrentDir();
assert curDir.exists() : "Current directory must exist.";
rename(curDir, tmpDir);
// rename previous to current
rename(prevDir, curDir);
// delete tmp dir
deleteDir(tmpDir);
LOG.info("Rollback of " + sd.getRoot()+ " is complete.");
}
isUpgradeFinalized = true;
// check whether name-node can start in regular mode
verifyDistributedUpgradeProgress(StartupOption.REGULAR);
}
private void doFinalize(StorageDirectory sd) throws IOException {
File prevDir = sd.getPreviousDir();
if (!prevDir.exists()) { // already discarded
LOG.info("Directory " + prevDir + " does not exist.");
LOG.info("Finalize upgrade for " + sd.getRoot()+ " is not required.");
return;
}
LOG.info("Finalizing upgrade for storage directory "
+ sd.getRoot() + "."
+ (getLayoutVersion()==0 ? "" :
"\n cur LV = " + this.getLayoutVersion()
+ "; cur CTime = " + this.getCTime()));
assert sd.getCurrentDir().exists() : "Current directory must exist.";
final File tmpDir = sd.getFinalizedTmp();
// rename previous to tmp and remove
rename(prevDir, tmpDir);
deleteDir(tmpDir);
isUpgradeFinalized = true;
LOG.info("Finalize upgrade for " + sd.getRoot()+ " is complete.");
}
/**
* Load image from a checkpoint directory and save it into the current one.
* @throws IOException
*/
void doImportCheckpoint() throws IOException {
FSNamesystem fsNamesys = getFSNamesystem();
FSImage ckptImage = new FSImage(fsNamesys);
// replace real image with the checkpoint image
FSImage realImage = fsNamesys.getFSImage();
assert realImage == this;
fsNamesys.dir.fsImage = ckptImage;
// load from the checkpoint dirs
try {
ckptImage.recoverTransitionRead(checkpointDirs, checkpointEditsDirs,
StartupOption.REGULAR);
} finally {
ckptImage.close();
}
// return back the real image
realImage.setStorageInfo(ckptImage);
checkpointTime = ckptImage.checkpointTime;
fsNamesys.dir.fsImage = realImage;
// and save it but keep the same checkpointTime
saveNamespace(false);
}
void finalizeUpgrade() throws IOException {
for (Iterator<StorageDirectory> it =
dirIterator(); it.hasNext();) {
doFinalize(it.next());
}
}
boolean isUpgradeFinalized() {
return isUpgradeFinalized;
}
protected void getFields(Properties props,
StorageDirectory sd
) throws IOException {
super.getFields(props, sd);
if (layoutVersion == 0)
throw new IOException("NameNode directory "
+ sd.getRoot() + " is not formatted.");
String sDUS, sDUV;
sDUS = props.getProperty("distributedUpgradeState");
sDUV = props.getProperty("distributedUpgradeVersion");
setDistributedUpgradeState(
sDUS == null? false : Boolean.parseBoolean(sDUS),
sDUV == null? getLayoutVersion() : Integer.parseInt(sDUV));
this.checkpointTime = readCheckpointTime(sd);
}
/**
* Determine the checkpoint time of the specified StorageDirectory
*
* @param sd StorageDirectory to check
* @return If file exists and can be read, last checkpoint time. If not, 0L.
* @throws IOException On errors processing file pointed to by sd
*/
long readCheckpointTime(StorageDirectory sd) throws IOException {
File timeFile = getImageFile(sd, NameNodeFile.TIME);
long timeStamp = 0L;
if (timeFile.exists() && timeFile.canRead()) {
DataInputStream in = new DataInputStream(new FileInputStream(timeFile));
try {
timeStamp = in.readLong();
} finally {
in.close();
}
}
return timeStamp;
}
/**
* Write last checkpoint time and version file into the storage directory.
*
* The version file should always be written last.
* Missing or corrupted version file indicates that
* the checkpoint is not valid.
*
* @param sd storage directory
* @throws IOException
*/
protected void setFields(Properties props,
StorageDirectory sd
) throws IOException {
super.setFields(props, sd);
boolean uState = getDistributedUpgradeState();
int uVersion = getDistributedUpgradeVersion();
if(uState && uVersion != getLayoutVersion()) {
props.setProperty("distributedUpgradeState", Boolean.toString(uState));
props.setProperty("distributedUpgradeVersion", Integer.toString(uVersion));
}
writeCheckpointTime(sd);
}
/**
* Write last checkpoint time into a separate file.
*
* @param sd
* @throws IOException
*/
void writeCheckpointTime(StorageDirectory sd) throws IOException {
if (checkpointTime < 0L)
return; // do not write negative time
File timeFile = getImageFile(sd, NameNodeFile.TIME);
if (timeFile.exists() && ! timeFile.delete()) {
LOG.error("Cannot delete chekpoint time file: "
+ timeFile.getCanonicalPath());
}
DataOutputStream out = new DataOutputStream(
new FileOutputStream(timeFile));
try {
out.writeLong(checkpointTime);
} finally {
out.close();
}
}
/**
* Record new checkpoint time in order to
* distinguish healthy directories from the removed ones.
* If there is an error writing new checkpoint time, the corresponding
* storage directory is removed from the list.
*/
void incrementCheckpointTime() {
setCheckpointTime(checkpointTime + 1);
}
/**
* The age of the namespace state.<p>
* Reflects the latest time the image was saved.
* Modified with every save or a checkpoint.
* Persisted in VERSION file.
*/
long getCheckpointTime() {
return checkpointTime;
}
void setCheckpointTime(long newCpT) {
checkpointTime = newCpT;
// Write new checkpoint time in all storage directories
for(Iterator<StorageDirectory> it =
dirIterator(); it.hasNext();) {
StorageDirectory sd = it.next();
try {
writeCheckpointTime(sd);
} catch(IOException e) {
// Close any edits stream associated with this dir and remove directory
LOG.warn("incrementCheckpointTime failed on " + sd.getRoot().getPath() + ";type="+sd.getStorageDirType());
}
}
}
/**
* @param sds - array of SDs to process
* @param propagate - flag, if set - then call corresponding EditLog stream's
* processIOError function.
*/
void processIOError(ArrayList<StorageDirectory> sds, boolean propagate) {
ArrayList<EditLogOutputStream> al = null;
for(StorageDirectory sd:sds) {
// if has a stream assosiated with it - remove it too..
if (propagate && sd.getStorageDirType().isOfType(NameNodeDirType.EDITS)) {
EditLogOutputStream eStream = editLog.getEditsStream(sd);
if(al == null) al = new ArrayList<EditLogOutputStream>(1);
al.add(eStream);
}
for (Iterator<StorageDirectory> it = dirIterator(); it.hasNext();) {
StorageDirectory sd1 = it.next();
if (sd.equals(sd1)) {
//add storage to the removed list
LOG.warn("FSImage:processIOError: removing storage: "
+ sd.getRoot().getPath());
try {
sd1.unlock(); //unlock before removing (in case it will be restored)
} catch (Exception e) {
// nothing
}
removedStorageDirs.add(sd1);
it.remove();
break;
}
}
}
// if there are some edit log streams to remove
if(propagate && al != null)
editLog.processIOError(al, false);
//if called from edits log, the it will call increment from there
if(propagate) incrementCheckpointTime();
}
public FSEditLog getEditLog() {
return editLog;
}
public boolean isConversionNeeded(StorageDirectory sd) throws IOException {
File oldImageDir = new File(sd.getRoot(), "image");
if (!oldImageDir.exists()) {
if(sd.getVersionFile().exists())
throw new InconsistentFSStateException(sd.getRoot(),
oldImageDir + " does not exist.");
return false;
}
// check the layout version inside the image file
File oldF = new File(oldImageDir, "fsimage");
RandomAccessFile oldFile = new RandomAccessFile(oldF, "rws");
try {
oldFile.seek(0);
int odlVersion = oldFile.readInt();
if (odlVersion < LAST_PRE_UPGRADE_LAYOUT_VERSION)
return false;
} finally {
oldFile.close();
}
return true;
}
//
// Atomic move sequence, to recover from interrupted checkpoint
//
boolean recoverInterruptedCheckpoint(StorageDirectory nameSD,
StorageDirectory editsSD)
throws IOException {
boolean needToSave = false;
File curFile = getImageFile(nameSD, NameNodeFile.IMAGE);
File ckptFile = getImageFile(nameSD, NameNodeFile.IMAGE_NEW);
//
// If we were in the midst of a checkpoint
//
if (ckptFile.exists()) {
needToSave = true;
if (getImageFile(editsSD, NameNodeFile.EDITS_NEW).exists()) {
//
// checkpointing migth have uploaded a new
// merged image, but we discard it here because we are
// not sure whether the entire merged image was uploaded
// before the namenode crashed.
//
if (!ckptFile.delete()) {
throw new IOException("Unable to delete " + ckptFile);
}
} else {
//
// checkpointing was in progress when the namenode
// shutdown. The fsimage.ckpt was created and the edits.new
// file was moved to edits. We complete that checkpoint by
// moving fsimage.new to fsimage. There is no need to
// update the fstime file here. renameTo fails on Windows
// if the destination file already exists.
//
if (!ckptFile.renameTo(curFile)) {
if (!curFile.delete())
LOG.warn("Unable to delete dir " + curFile + " before rename");
if (!ckptFile.renameTo(curFile)) {
throw new IOException("Unable to rename " + ckptFile +
" to " + curFile);
}
}
}
}
return needToSave;
}
/**
* Choose latest image from one of the directories,
* load it and merge with the edits from that directory.
*
* Saving and loading fsimage should never trigger symlink resolution.
* The paths that are persisted do not have *intermediate* symlinks
* because intermediate symlinks are resolved at the time files,
* directories, and symlinks are created. All paths accessed while
* loading or saving fsimage should therefore only see symlinks as
* the final path component, and the functions called below do not
* resolve symlinks that are the final path component.
*
* @return whether the image should be saved
* @throws IOException
*/
boolean loadFSImage() throws IOException {
long latestNameCheckpointTime = Long.MIN_VALUE;
long latestEditsCheckpointTime = Long.MIN_VALUE;
boolean needToSave = false;
isUpgradeFinalized = true;
StorageDirectory latestNameSD = null;
StorageDirectory latestEditsSD = null;
Collection<String> imageDirs = new ArrayList<String>();
Collection<String> editsDirs = new ArrayList<String>();
// Set to determine if all of storageDirectories share the same checkpoint
Set<Long> checkpointTimes = new HashSet<Long>();
// Process each of the storage directories to find the pair of
// newest image file and edit file
for (Iterator<StorageDirectory> it = dirIterator(); it.hasNext();) {
StorageDirectory sd = it.next();
// Was the file just formatted?
if (!sd.getVersionFile().exists()) {
needToSave |= true;
continue;
}
boolean imageExists = false;
boolean editsExists = false;
// Determine if sd is image, edits or both
if (sd.getStorageDirType().isOfType(NameNodeDirType.IMAGE)) {
imageExists = getImageFile(sd, NameNodeFile.IMAGE).exists();
imageDirs.add(sd.getRoot().getCanonicalPath());
}
if (sd.getStorageDirType().isOfType(NameNodeDirType.EDITS)) {
editsExists = getImageFile(sd, NameNodeFile.EDITS).exists();
editsDirs.add(sd.getRoot().getCanonicalPath());
}
checkpointTime = readCheckpointTime(sd);
checkpointTimes.add(checkpointTime);
if (sd.getStorageDirType().isOfType(NameNodeDirType.IMAGE) &&
(latestNameCheckpointTime < checkpointTime) && imageExists) {
latestNameCheckpointTime = checkpointTime;
latestNameSD = sd;
}
if (sd.getStorageDirType().isOfType(NameNodeDirType.EDITS) &&
(latestEditsCheckpointTime < checkpointTime) && editsExists) {
latestEditsCheckpointTime = checkpointTime;
latestEditsSD = sd;
}
// check that we have a valid, non-default checkpointTime
if (checkpointTime <= 0L)
needToSave |= true;
// set finalized flag
isUpgradeFinalized = isUpgradeFinalized && !sd.getPreviousDir().exists();
}
// We should have at least one image and one edits dirs
if (latestNameSD == null)
throw new IOException("Image file is not found in " + imageDirs);
if (latestEditsSD == null)
throw new IOException("Edits file is not found in " + editsDirs);
// Make sure we are loading image and edits from same checkpoint
if (latestNameCheckpointTime > latestEditsCheckpointTime
&& latestNameSD != latestEditsSD
&& latestNameSD.getStorageDirType() == NameNodeDirType.IMAGE
&& latestEditsSD.getStorageDirType() == NameNodeDirType.EDITS) {
// This is a rare failure when NN has image-only and edits-only
// storage directories, and fails right after saving images,
// in some of the storage directories, but before purging edits.
// See -NOTE- in saveNamespace().
LOG.error("This is a rare failure scenario!!!");
LOG.error("Image checkpoint time " + latestNameCheckpointTime +
" > edits checkpoint time " + latestEditsCheckpointTime);
LOG.error("Name-node will treat the image as the latest state of " +
"the namespace. Old edits will be discarded.");
} else if (latestNameCheckpointTime != latestEditsCheckpointTime)
throw new IOException("Inconsistent storage detected, " +
"image and edits checkpoint times do not match. " +
"image checkpoint time = " + latestNameCheckpointTime +
"edits checkpoint time = " + latestEditsCheckpointTime);
// If there was more than one checkpointTime recorded we should save
needToSave |= checkpointTimes.size() != 1;
// Recover from previous interrupted checkpoint, if any
needToSave |= recoverInterruptedCheckpoint(latestNameSD, latestEditsSD);
long startTime = FSNamesystem.now();
long imageSize = getImageFile(latestNameSD, NameNodeFile.IMAGE).length();
//
// Load in bits
//
latestNameSD.read();
needToSave |= loadFSImage(getImageFile(latestNameSD, NameNodeFile.IMAGE));
LOG.info("Image file of size " + imageSize + " loaded in "
+ (FSNamesystem.now() - startTime)/1000 + " seconds.");
// Load latest edits
if (latestNameCheckpointTime > latestEditsCheckpointTime)
// the image is already current, discard edits
needToSave |= true;
else // latestNameCheckpointTime == latestEditsCheckpointTime
needToSave |= (loadFSEdits(latestEditsSD) > 0);
return needToSave;
}
/**
* Load in the filesystem image from file. It's a big list of
* filenames and blocks. Return whether we should
* "re-save" and consolidate the edit-logs
*/
boolean loadFSImage(File curFile) throws IOException {
assert this.getLayoutVersion() < 0 : "Negative layout version is expected.";
assert curFile != null : "curFile is null";
FSNamesystem fsNamesys = getFSNamesystem();
FSDirectory fsDir = fsNamesys.dir;
//
// Load in bits
//
boolean needToSave = true;
DataInputStream in = new DataInputStream(new BufferedInputStream(
new FileInputStream(curFile)));
try {
/*
* Note: Remove any checks for version earlier than
* Storage.LAST_UPGRADABLE_LAYOUT_VERSION since we should never get
* to here with older images.
*/
/*
* TODO we need to change format of the image file
* it should not contain version and namespace fields
*/
// read image version: first appeared in version -1
int imgVersion = in.readInt();
// read namespaceID: first appeared in version -2
this.namespaceID = in.readInt();
// read number of files
long numFiles;
if (imgVersion <= -16) {
numFiles = in.readLong();
} else {
numFiles = in.readInt();
}
this.layoutVersion = imgVersion;
// read in the last generation stamp.
if (imgVersion <= -12) {
long genstamp = in.readLong();
fsNamesys.setGenerationStamp(genstamp);
}
needToSave = (imgVersion != FSConstants.LAYOUT_VERSION);
// read file info
short replication = fsNamesys.getDefaultReplication();
LOG.info("Number of files = " + numFiles);
String path;
String parentPath = "";
INodeDirectory parentINode = fsDir.rootDir;
for (long i = 0; i < numFiles; i++) {
long modificationTime = 0;
long atime = 0;
long blockSize = 0;
path = readString(in);
replication = in.readShort();
replication = editLog.adjustReplication(replication);
modificationTime = in.readLong();
if (imgVersion <= -17) {
atime = in.readLong();
}
if (imgVersion <= -8) {
blockSize = in.readLong();
}
int numBlocks = in.readInt();
Block blocks[] = null;
// for older versions, a blocklist of size 0
// indicates a directory.
if ((-9 <= imgVersion && numBlocks > 0) ||
(imgVersion < -9 && numBlocks >= 0)) {
blocks = new Block[numBlocks];
for (int j = 0; j < numBlocks; j++) {
blocks[j] = new Block();
if (-14 < imgVersion) {
blocks[j].set(in.readLong(), in.readLong(),
GenerationStamp.GRANDFATHER_GENERATION_STAMP);
} else {
blocks[j].readFields(in);
}
}
}
// Older versions of HDFS does not store the block size in inode.
// If the file has more than one block, use the size of the
// first block as the blocksize. Otherwise use the default block size.
//
if (-8 <= imgVersion && blockSize == 0) {
if (numBlocks > 1) {
blockSize = blocks[0].getNumBytes();
} else {
long first = ((numBlocks == 1) ? blocks[0].getNumBytes(): 0);
blockSize = Math.max(fsNamesys.getDefaultBlockSize(), first);
}
}
// get quota only when the node is a directory
long nsQuota = -1L;
if (imgVersion <= -16 && blocks == null && numBlocks == -1) {
nsQuota = in.readLong();
}
long dsQuota = -1L;
if (imgVersion <= -18 && blocks == null && numBlocks == -1) {
dsQuota = in.readLong();
}
// Read the symlink only when the node is a symlink
String symlink = "";
if (imgVersion <= -23 && numBlocks == -2) {
symlink = Text.readString(in);
}
PermissionStatus permissions = fsNamesys.getUpgradePermission();
if (imgVersion <= -11) {
permissions = PermissionStatus.read(in);
}
if (path.length() == 0) { // it is the root
// update the root's attributes
if (nsQuota != -1 || dsQuota != -1) {
fsDir.rootDir.setQuota(nsQuota, dsQuota);
}
fsDir.rootDir.setModificationTime(modificationTime);
fsDir.rootDir.setPermissionStatus(permissions);
continue;
}
// check if the new inode belongs to the same parent
if(!isParent(path, parentPath)) {
parentINode = null;
parentPath = getParent(path);
}
// add new inode
parentINode = fsDir.addToParent(path, parentINode, permissions,
blocks, symlink, replication, modificationTime,
atime, nsQuota, dsQuota, blockSize);
}
// load datanode info
this.loadDatanodes(imgVersion, in);
// load Files Under Construction
this.loadFilesUnderConstruction(imgVersion, in, fsNamesys);
this.loadSecretManagerState(imgVersion, in, fsNamesys);
} finally {
in.close();
}
return needToSave;
}
/**
* Return string representing the parent of the given path.
*/
String getParent(String path) {
return path.substring(0, path.lastIndexOf(Path.SEPARATOR));
}
private boolean isParent(String path, String parent) {
return parent != null && path != null
&& path.indexOf(parent) == 0
&& path.lastIndexOf(Path.SEPARATOR) == parent.length();
}
/**
* Load and merge edits from two edits files
*
* @param sd storage directory
* @return number of edits loaded
* @throws IOException
*/
int loadFSEdits(StorageDirectory sd) throws IOException {
int numEdits = 0;
EditLogFileInputStream edits =
new EditLogFileInputStream(getImageFile(sd, NameNodeFile.EDITS));
numEdits = editLog.loadFSEdits(edits);
edits.close();
File editsNew = getImageFile(sd, NameNodeFile.EDITS_NEW);
if (editsNew.exists() && editsNew.length() > 0) {
edits = new EditLogFileInputStream(editsNew);
numEdits += editLog.loadFSEdits(edits);
edits.close();
}
// update the counts.
getFSNamesystem().dir.updateCountForINodeWithQuota();
return numEdits;
}
/**
* Save the contents of the FS image to the file.
*/
void saveFSImage(File newFile) throws IOException {
FSNamesystem fsNamesys = getFSNamesystem();
FSDirectory fsDir = fsNamesys.dir;
long startTime = FSNamesystem.now();
//
// Write out data
//
DataOutputStream out = new DataOutputStream(
new BufferedOutputStream(
new FileOutputStream(newFile)));
try {
out.writeInt(FSConstants.LAYOUT_VERSION);
out.writeInt(namespaceID);
out.writeLong(fsDir.rootDir.numItemsInTree());
out.writeLong(fsNamesys.getGenerationStamp());
byte[] byteStore = new byte[4*FSConstants.MAX_PATH_LENGTH];
ByteBuffer strbuf = ByteBuffer.wrap(byteStore);
// save the root
saveINode2Image(strbuf, fsDir.rootDir, out);
// save the rest of the nodes
saveImage(strbuf, 0, fsDir.rootDir, out);
fsNamesys.saveFilesUnderConstruction(out);
fsNamesys.saveSecretManagerState(out);
strbuf = null;
} finally {
out.close();
}
LOG.info("Image file of size " + newFile.length() + " saved in "
+ (FSNamesystem.now() - startTime)/1000 + " seconds.");
}
/**
* Save the contents of the FS image and create empty edits.
*
* In order to minimize the recovery effort in case of failure during
* saveNamespace the algorithm reduces discrepancy between directory states
* by performing updates in the following order:
* <ol>
* <li> rename current to lastcheckpoint.tmp for all of them,</li>
* <li> save image and recreate edits for all of them,</li>
* <li> rename lastcheckpoint.tmp to previous.checkpoint.</li>
* </ol>
* On stage (2) we first save all images, then recreate edits.
* Otherwise the name-node may purge all edits and fail,
* in which case the journal will be lost.
*/
void saveNamespace(boolean renewCheckpointTime) throws IOException {
assert editLog != null : "editLog must be initialized";
editLog.close();
if(renewCheckpointTime)
this.checkpointTime = FSNamesystem.now();
ArrayList<StorageDirectory> errorSDs = new ArrayList<StorageDirectory>();
// mv current -> lastcheckpoint.tmp
for (Iterator<StorageDirectory> it = dirIterator(); it.hasNext();) {
StorageDirectory sd = it.next();
try {
moveCurrent(sd);
} catch(IOException ie) {
LOG.error("Unable to move current for " + sd.getRoot(), ie);
errorSDs.add(sd);
}
}
// save images into current
for (Iterator<StorageDirectory> it = dirIterator(NameNodeDirType.IMAGE);
it.hasNext();) {
StorageDirectory sd = it.next();
try {
saveCurrent(sd);
} catch(IOException ie) {
LOG.error("Unable to save image for " + sd.getRoot(), ie);
errorSDs.add(sd);
}
}
// -NOTE-
// If NN has image-only and edits-only storage directories and fails here
// the image will have the latest namespace state.
// During startup the image-only directories will recover by discarding
// lastcheckpoint.tmp, while
// the edits-only directories will recover by falling back
// to the old state contained in their lastcheckpoint.tmp.
// The edits directories should be discarded during startup because their
// checkpointTime is older than that of image directories.
// recreate edits in current
for (Iterator<StorageDirectory> it = dirIterator(NameNodeDirType.EDITS);
it.hasNext();) {
StorageDirectory sd = it.next();
try {
saveCurrent(sd);
} catch(IOException ie) {
LOG.error("Unable to save edits for " + sd.getRoot(), ie);
errorSDs.add(sd);
}
}
// mv lastcheckpoint.tmp -> previous.checkpoint
for (Iterator<StorageDirectory> it = dirIterator(); it.hasNext();) {
StorageDirectory sd = it.next();
try {
moveLastCheckpoint(sd);
} catch(IOException ie) {
LOG.error("Unable to move last checkpoint for " + sd.getRoot(), ie);
errorSDs.add(sd);
}
}
processIOError(errorSDs, false);
if(!editLog.isOpen()) editLog.open();
ckptState = CheckpointStates.UPLOAD_DONE;
}
/**
* Save current image and empty journal into {@code current} directory.
*/
protected void saveCurrent(StorageDirectory sd) throws IOException {
File curDir = sd.getCurrentDir();
NameNodeDirType dirType = (NameNodeDirType)sd.getStorageDirType();
// save new image or new edits
if (!curDir.exists() && !curDir.mkdir())
throw new IOException("Cannot create directory " + curDir);
if (dirType.isOfType(NameNodeDirType.IMAGE))
saveFSImage(getImageFile(sd, NameNodeFile.IMAGE));
if (dirType.isOfType(NameNodeDirType.EDITS))
editLog.createEditLogFile(getImageFile(sd, NameNodeFile.EDITS));
// write version and time files
sd.write();
}
/**
* Move {@code current} to {@code lastcheckpoint.tmp} and
* recreate empty {@code current}.
* {@code current} is moved only if it is well formatted,
* that is contains VERSION file.
*
* @see org.apache.hadoop.hdfs.server.common.Storage.StorageDirectory#getLastCheckpointTmp()
* @see org.apache.hadoop.hdfs.server.common.Storage.StorageDirectory#getPreviousCheckpoint()
*/
protected void moveCurrent(StorageDirectory sd)
throws IOException {
File curDir = sd.getCurrentDir();
File tmpCkptDir = sd.getLastCheckpointTmp();
// mv current -> lastcheckpoint.tmp
// only if current is formatted - has VERSION file
if(sd.getVersionFile().exists()) {
assert curDir.exists() : curDir + " directory must exist.";
assert !tmpCkptDir.exists() : tmpCkptDir + " directory must not exist.";
rename(curDir, tmpCkptDir);
}
// recreate current
if(!curDir.exists() && !curDir.mkdir())
throw new IOException("Cannot create directory " + curDir);
}
/**
* Move {@code lastcheckpoint.tmp} to {@code previous.checkpoint}
*
* @see org.apache.hadoop.hdfs.server.common.Storage.StorageDirectory#getPreviousCheckpoint()
* @see org.apache.hadoop.hdfs.server.common.Storage.StorageDirectory#getLastCheckpointTmp()
*/
protected void moveLastCheckpoint(StorageDirectory sd)
throws IOException {
File tmpCkptDir = sd.getLastCheckpointTmp();
File prevCkptDir = sd.getPreviousCheckpoint();
// remove previous.checkpoint
if (prevCkptDir.exists())
deleteDir(prevCkptDir);
// mv lastcheckpoint.tmp -> previous.checkpoint
if(tmpCkptDir.exists())
rename(tmpCkptDir, prevCkptDir);
}
/**
* Generate new namespaceID.
*
* namespaceID is a persistent attribute of the namespace.
* It is generated when the namenode is formatted and remains the same
* during the life cycle of the namenode.
* When a datanodes register they receive it as the registrationID,
* which is checked every time the datanode is communicating with the
* namenode. Datanodes that do not 'know' the namespaceID are rejected.
*
* @return new namespaceID
*/
private int newNamespaceID() {
Random r = new Random();
r.setSeed(FSNamesystem.now());
int newID = 0;
while(newID == 0)
newID = r.nextInt(0x7FFFFFFF); // use 31 bits only
return newID;
}
/** Create new dfs name directory. Caution: this destroys all files
* in this filesystem. */
void format(StorageDirectory sd) throws IOException {
sd.clearDirectory(); // create currrent dir
sd.lock();
try {
saveCurrent(sd);
} finally {
sd.unlock();
}
LOG.info("Storage directory " + sd.getRoot()
+ " has been successfully formatted.");
}
public void format() throws IOException {
this.layoutVersion = FSConstants.LAYOUT_VERSION;
this.namespaceID = newNamespaceID();
this.cTime = 0L;
this.checkpointTime = FSNamesystem.now();
for (Iterator<StorageDirectory> it =
dirIterator(); it.hasNext();) {
StorageDirectory sd = it.next();
format(sd);
}
}
/*
* Save one inode's attributes to the image.
*/
private static void saveINode2Image(ByteBuffer name,
INode node,
DataOutputStream out) throws IOException {
int nameLen = name.position();
out.writeShort(nameLen);
out.write(name.array(), name.arrayOffset(), nameLen);
if (node.isDirectory()) {
out.writeShort(0); // replication
out.writeLong(node.getModificationTime());
out.writeLong(0); // access time
out.writeLong(0); // preferred block size
out.writeInt(-1); // # of blocks
out.writeLong(node.getNsQuota());
out.writeLong(node.getDsQuota());
FILE_PERM.fromShort(node.getFsPermissionShort());
PermissionStatus.write(out, node.getUserName(),
node.getGroupName(),
FILE_PERM);
} else if (node.isLink()) {
out.writeShort(0); // replication
out.writeLong(0); // modification time
out.writeLong(0); // access time
out.writeLong(0); // preferred block size
out.writeInt(-2); // # of blocks
Text.writeString(out, ((INodeSymlink)node).getLinkValue());
FILE_PERM.fromShort(node.getFsPermissionShort());
PermissionStatus.write(out, node.getUserName(),
node.getGroupName(),
FILE_PERM);
} else {
INodeFile fileINode = (INodeFile)node;
out.writeShort(fileINode.getReplication());
out.writeLong(fileINode.getModificationTime());
out.writeLong(fileINode.getAccessTime());
out.writeLong(fileINode.getPreferredBlockSize());
Block[] blocks = fileINode.getBlocks();
out.writeInt(blocks.length);
for (Block blk : blocks)
blk.write(out);
FILE_PERM.fromShort(fileINode.getFsPermissionShort());
PermissionStatus.write(out, fileINode.getUserName(),
fileINode.getGroupName(),
FILE_PERM);
}
}
/**
* Save file tree image starting from the given root.
* This is a recursive procedure, which first saves all children of
* a current directory and then moves inside the sub-directories.
*/
private static void saveImage(ByteBuffer parentPrefix,
int prefixLength,
INodeDirectory current,
DataOutputStream out) throws IOException {
int newPrefixLength = prefixLength;
if (current.getChildrenRaw() == null)
return;
for(INode child : current.getChildren()) {
// print all children first
parentPrefix.position(prefixLength);
parentPrefix.put(PATH_SEPARATOR).put(child.getLocalNameBytes());
saveINode2Image(parentPrefix, child, out);
}
for(INode child : current.getChildren()) {
if(!child.isDirectory())
continue;
parentPrefix.position(prefixLength);
parentPrefix.put(PATH_SEPARATOR).put(child.getLocalNameBytes());
newPrefixLength = parentPrefix.position();
saveImage(parentPrefix, newPrefixLength, (INodeDirectory)child, out);
}
parentPrefix.position(prefixLength);
}
void loadDatanodes(int version, DataInputStream in) throws IOException {
if (version > -3) // pre datanode image version
return;
if (version <= -12) {
return; // new versions do not store the datanodes any more.
}
int size = in.readInt();
for(int i = 0; i < size; i++) {
DatanodeImage nodeImage = new DatanodeImage();
nodeImage.readFields(in);
// We don't need to add these descriptors any more.
}
}
private void loadFilesUnderConstruction(int version, DataInputStream in,
FSNamesystem fs) throws IOException {
FSDirectory fsDir = fs.dir;
if (version > -13) // pre lease image version
return;
int size = in.readInt();
LOG.info("Number of files under construction = " + size);
for (int i = 0; i < size; i++) {
INodeFileUnderConstruction cons = readINodeUnderConstruction(in);
// verify that file exists in namespace
String path = cons.getLocalName();
INode old = fsDir.getFileINode(path);
if (old == null) {
throw new IOException("Found lease for non-existent file " + path);
}
if (old.isDirectory()) {
throw new IOException("Found lease for directory " + path);
}
INodeFile oldnode = (INodeFile) old;
fsDir.replaceNode(path, oldnode, cons);
fs.leaseManager.addLease(cons.getClientName(), path);
}
}
private void loadSecretManagerState(int version, DataInputStream in,
FSNamesystem fs) throws IOException {
if (version > -23) {
//SecretManagerState is not available.
//This must not happen if security is turned on.
return;
}
fs.loadSecretManagerState(in);
}
// Helper function that reads in an INodeUnderConstruction
// from the input stream
//
static INodeFileUnderConstruction readINodeUnderConstruction(
DataInputStream in) throws IOException {
byte[] name = readBytes(in);
short blockReplication = in.readShort();
long modificationTime = in.readLong();
long preferredBlockSize = in.readLong();
int numBlocks = in.readInt();
BlockInfo[] blocks = new BlockInfo[numBlocks];
Block blk = new Block();
int i = 0;
for (; i < numBlocks-1; i++) {
blk.readFields(in);
blocks[i] = new BlockInfo(blk, blockReplication);
}
// last block is UNDER_CONSTRUCTION
if(numBlocks > 0) {
blk.readFields(in);
blocks[i] = new BlockInfoUnderConstruction(
blk, blockReplication, BlockUCState.UNDER_CONSTRUCTION, null);
}
PermissionStatus perm = PermissionStatus.read(in);
String clientName = readString(in);
String clientMachine = readString(in);
// These locations are not used at all
int numLocs = in.readInt();
DatanodeDescriptor[] locations = new DatanodeDescriptor[numLocs];
for (i = 0; i < numLocs; i++) {
locations[i] = new DatanodeDescriptor();
locations[i].readFields(in);
}
return new INodeFileUnderConstruction(name,
blockReplication,
modificationTime,
preferredBlockSize,
blocks,
perm,
clientName,
clientMachine,
null);
}
// Helper function that writes an INodeUnderConstruction
// into the input stream
//
static void writeINodeUnderConstruction(DataOutputStream out,
INodeFileUnderConstruction cons,
String path)
throws IOException {
writeString(path, out);
out.writeShort(cons.getReplication());
out.writeLong(cons.getModificationTime());
out.writeLong(cons.getPreferredBlockSize());
int nrBlocks = cons.getBlocks().length;
out.writeInt(nrBlocks);
for (int i = 0; i < nrBlocks; i++) {
cons.getBlocks()[i].write(out);
}
cons.getPermissionStatus().write(out);
writeString(cons.getClientName(), out);
writeString(cons.getClientMachine(), out);
out.writeInt(0); // do not store locations of last block
}
/**
* Moves fsimage.ckpt to fsImage and edits.new to edits
* Reopens the new edits file.
*/
void rollFSImage() throws IOException {
rollFSImage(true);
}
void rollFSImage(boolean renewCheckpointTime) throws IOException {
if (ckptState != CheckpointStates.UPLOAD_DONE
&& !(ckptState == CheckpointStates.ROLLED_EDITS
&& getNumStorageDirs(NameNodeDirType.IMAGE) == 0)) {
throw new IOException("Cannot roll fsImage before rolling edits log.");
}
for (Iterator<StorageDirectory> it =
dirIterator(NameNodeDirType.IMAGE); it.hasNext();) {
StorageDirectory sd = it.next();
File ckpt = getImageFile(sd, NameNodeFile.IMAGE_NEW);
if (!ckpt.exists()) {
throw new IOException("Checkpoint file " + ckpt +
" does not exist");
}
}
editLog.purgeEditLog(); // renamed edits.new to edits
LOG.debug("rollFSImage after purgeEditLog: storageList=" + listStorageDirectories());
//
// Renames new image
//
renameCheckpoint();
resetVersion(renewCheckpointTime);
}
/**
* Renames new image
*/
void renameCheckpoint() {
ArrayList<StorageDirectory> al = null;
for (Iterator<StorageDirectory> it =
dirIterator(NameNodeDirType.IMAGE); it.hasNext();) {
StorageDirectory sd = it.next();
File ckpt = getImageFile(sd, NameNodeFile.IMAGE_NEW);
File curFile = getImageFile(sd, NameNodeFile.IMAGE);
// renameTo fails on Windows if the destination file
// already exists.
LOG.debug("renaming " + ckpt.getAbsolutePath() + " to " + curFile.getAbsolutePath());
if (!ckpt.renameTo(curFile)) {
if (!curFile.delete() || !ckpt.renameTo(curFile)) {
LOG.warn("renaming " + ckpt.getAbsolutePath() + " to " +
curFile.getAbsolutePath() + " FAILED");
if(al == null) al = new ArrayList<StorageDirectory> (1);
al.add(sd);
}
}
}
if(al != null) processIOError(al, true);
}
/**
* Updates version and fstime files in all directories (fsimage and edits).
*/
void resetVersion(boolean renewCheckpointTime) throws IOException {
this.layoutVersion = FSConstants.LAYOUT_VERSION;
if(renewCheckpointTime)
this.checkpointTime = FSNamesystem.now();
ArrayList<StorageDirectory> al = null;
for (Iterator<StorageDirectory> it =
dirIterator(); it.hasNext();) {
StorageDirectory sd = it.next();
// delete old edits if sd is the image only the directory
if (!sd.getStorageDirType().isOfType(NameNodeDirType.EDITS)) {
File editsFile = getImageFile(sd, NameNodeFile.EDITS);
if(editsFile.exists() && !editsFile.delete())
throw new IOException("Cannot delete edits file "
+ editsFile.getCanonicalPath());
}
// delete old fsimage if sd is the edits only the directory
if (!sd.getStorageDirType().isOfType(NameNodeDirType.IMAGE)) {
File imageFile = getImageFile(sd, NameNodeFile.IMAGE);
if(imageFile.exists() && !imageFile.delete())
throw new IOException("Cannot delete image file "
+ imageFile.getCanonicalPath());
}
try {
sd.write();
} catch (IOException e) {
LOG.error("Cannot write file " + sd.getRoot(), e);
if(al == null) al = new ArrayList<StorageDirectory> (1);
al.add(sd);
}
}
if(al != null) processIOError(al, true);
ckptState = FSImage.CheckpointStates.START;
}
CheckpointSignature rollEditLog() throws IOException {
getEditLog().rollEditLog();
ckptState = CheckpointStates.ROLLED_EDITS;
// If checkpoint fails this should be the most recent image, therefore
incrementCheckpointTime();
return new CheckpointSignature(this);
}
/**
* This is called just before a new checkpoint is uploaded to the
* namenode.
*/
void validateCheckpointUpload(CheckpointSignature sig) throws IOException {
if (ckptState != CheckpointStates.ROLLED_EDITS) {
throw new IOException("Namenode is not expecting an new image " +
ckptState);
}
// verify token
long modtime = getEditLog().getFsEditTime();
if (sig.editsTime != modtime) {
throw new IOException("Namenode has an edit log with timestamp of " +
DATE_FORM.format(new Date(modtime)) +
" but new checkpoint was created using editlog " +
" with timestamp " +
DATE_FORM.format(new Date(sig.editsTime)) +
". Checkpoint Aborted.");
}
sig.validateStorageInfo(this);
ckptState = FSImage.CheckpointStates.UPLOAD_START;
}
/**
* Start checkpoint.
* <p>
* If backup storage contains image that is newer than or incompatible with
* what the active name-node has, then the backup node should shutdown.<br>
* If the backup image is older than the active one then it should
* be discarded and downloaded from the active node.<br>
* If the images are the same then the backup image will be used as current.
*
* @param bnReg the backup node registration.
* @param nnReg this (active) name-node registration.
* @return {@link NamenodeCommand} if backup node should shutdown or
* {@link CheckpointCommand} prescribing what backup node should
* do with its image.
* @throws IOException
*/
NamenodeCommand startCheckpoint(NamenodeRegistration bnReg, // backup node
NamenodeRegistration nnReg) // active name-node
throws IOException {
String msg = null;
// Verify that checkpoint is allowed
if(bnReg.getNamespaceID() != this.getNamespaceID())
msg = "Name node " + bnReg.getAddress()
+ " has incompatible namespace id: " + bnReg.getNamespaceID()
+ " expected: " + getNamespaceID();
else if(bnReg.isRole(NamenodeRole.ACTIVE))
msg = "Name node " + bnReg.getAddress()
+ " role " + bnReg.getRole() + ": checkpoint is not allowed.";
else if(bnReg.getLayoutVersion() < this.getLayoutVersion()
|| (bnReg.getLayoutVersion() == this.getLayoutVersion()
&& bnReg.getCTime() > this.getCTime())
|| (bnReg.getLayoutVersion() == this.getLayoutVersion()
&& bnReg.getCTime() == this.getCTime()
&& bnReg.getCheckpointTime() > this.checkpointTime))
// remote node has newer image age
msg = "Name node " + bnReg.getAddress()
+ " has newer image layout version: LV = " +bnReg.getLayoutVersion()
+ " cTime = " + bnReg.getCTime()
+ " checkpointTime = " + bnReg.getCheckpointTime()
+ ". Current version: LV = " + getLayoutVersion()
+ " cTime = " + getCTime()
+ " checkpointTime = " + checkpointTime;
if(msg != null) {
LOG.error(msg);
return new NamenodeCommand(NamenodeProtocol.ACT_SHUTDOWN);
}
boolean isImgObsolete = true;
if(bnReg.getLayoutVersion() == this.getLayoutVersion()
&& bnReg.getCTime() == this.getCTime()
&& bnReg.getCheckpointTime() == this.checkpointTime)
isImgObsolete = false;
boolean needToReturnImg = true;
if(getNumStorageDirs(NameNodeDirType.IMAGE) == 0)
// do not return image if there are no image directories
needToReturnImg = false;
CheckpointSignature sig = rollEditLog();
getEditLog().logJSpoolStart(bnReg, nnReg);
return new CheckpointCommand(sig, isImgObsolete, needToReturnImg);
}
/**
* End checkpoint.
* <p>
* Rename uploaded checkpoint to the new image;
* purge old edits file;
* rename edits.new to edits;
* redirect edit log streams to the new edits;
* update checkpoint time if the remote node is a checkpoint only node.
*
* @param sig
* @param remoteNNRole
* @throws IOException
*/
void endCheckpoint(CheckpointSignature sig,
NamenodeRole remoteNNRole) throws IOException {
sig.validateStorageInfo(this);
// Renew checkpoint time for the active if the other is a checkpoint-node.
// The checkpoint-node should have older image for the next checkpoint
// to take effect.
// The backup-node always has up-to-date image and will have the same
// checkpoint time as the active node.
boolean renewCheckpointTime = remoteNNRole.equals(NamenodeRole.CHECKPOINT);
rollFSImage(renewCheckpointTime);
}
CheckpointStates getCheckpointState() {
return ckptState;
}
void setCheckpointState(CheckpointStates cs) {
ckptState = cs;
}
/**
* This is called when a checkpoint upload finishes successfully.
*/
synchronized void checkpointUploadDone() {
ckptState = CheckpointStates.UPLOAD_DONE;
}
synchronized void close() throws IOException {
getEditLog().close();
unlockAll();
}
/**
* Return the name of the image file.
*/
File getFsImageName() {
StorageDirectory sd = null;
for (Iterator<StorageDirectory> it =
dirIterator(NameNodeDirType.IMAGE); it.hasNext();) {
sd = it.next();
if(sd.getRoot().canRead())
return getImageFile(sd, NameNodeFile.IMAGE);
}
return null;
}
/**
* See if any of removed storages iw "writable" again, and can be returned
* into service
*/
synchronized void attemptRestoreRemovedStorage() {
// if directory is "alive" - copy the images there...
if(!restoreFailedStorage || removedStorageDirs.size() == 0)
return; //nothing to restore
LOG.info("FSImage.attemptRestoreRemovedStorage: check removed(failed) " +
"storarge. removedStorages size = " + removedStorageDirs.size());
for(Iterator<StorageDirectory> it = this.removedStorageDirs.iterator(); it.hasNext();) {
StorageDirectory sd = it.next();
File root = sd.getRoot();
LOG.info("currently disabled dir " + root.getAbsolutePath() +
"; type="+sd.getStorageDirType() + ";canwrite="+root.canWrite());
try {
if(root.exists() && root.canWrite()) {
format(sd);
LOG.info("restoring dir " + sd.getRoot().getAbsolutePath());
if(sd.getStorageDirType().isOfType(NameNodeDirType.EDITS)) {
File eFile = getEditFile(sd);
editLog.addNewEditLogStream(eFile);
}
this.addStorageDir(sd); // restore
it.remove();
}
} catch(IOException e) {
LOG.warn("failed to restore " + sd.getRoot().getAbsolutePath(), e);
}
}
}
public File getFsEditName() throws IOException {
return getEditLog().getFsEditName();
}
File getFsTimeName() {
StorageDirectory sd = null;
// NameNodeFile.TIME shoul be same on all directories
for (Iterator<StorageDirectory> it =
dirIterator(); it.hasNext();)
sd = it.next();
return getImageFile(sd, NameNodeFile.TIME);
}
/**
* Return the name of the image file that is uploaded by periodic
* checkpointing.
*/
File[] getFsImageNameCheckpoint() {
ArrayList<File> list = new ArrayList<File>();
for (Iterator<StorageDirectory> it =
dirIterator(NameNodeDirType.IMAGE); it.hasNext();) {
list.add(getImageFile(it.next(), NameNodeFile.IMAGE_NEW));
}
return list.toArray(new File[list.size()]);
}
/**
* DatanodeImage is used to store persistent information
* about datanodes into the fsImage.
*/
static class DatanodeImage implements Writable {
DatanodeDescriptor node = new DatanodeDescriptor();
/////////////////////////////////////////////////
// Writable
/////////////////////////////////////////////////
/**
* Public method that serializes the information about a
* Datanode to be stored in the fsImage.
*/
public void write(DataOutput out) throws IOException {
new DatanodeID(node).write(out);
out.writeLong(node.getCapacity());
out.writeLong(node.getRemaining());
out.writeLong(node.getLastUpdate());
out.writeInt(node.getXceiverCount());
}
/**
* Public method that reads a serialized Datanode
* from the fsImage.
*/
public void readFields(DataInput in) throws IOException {
DatanodeID id = new DatanodeID();
id.readFields(in);
long capacity = in.readLong();
long remaining = in.readLong();
long lastUpdate = in.readLong();
int xceiverCount = in.readInt();
// update the DatanodeDescriptor with the data we read in
node.updateRegInfo(id);
node.setStorageID(id.getStorageID());
node.setCapacity(capacity);
node.setRemaining(remaining);
node.setLastUpdate(lastUpdate);
node.setXceiverCount(xceiverCount);
}
}
protected void corruptPreUpgradeStorage(File rootDir) throws IOException {
File oldImageDir = new File(rootDir, "image");
if (!oldImageDir.exists())
if (!oldImageDir.mkdir())
throw new IOException("Cannot create directory " + oldImageDir);
File oldImage = new File(oldImageDir, "fsimage");
if (!oldImage.exists())
// recreate old image file to let pre-upgrade versions fail
if (!oldImage.createNewFile())
throw new IOException("Cannot create file " + oldImage);
RandomAccessFile oldFile = new RandomAccessFile(oldImage, "rws");
// write new version into old image file
try {
writeCorruptedData(oldFile);
} finally {
oldFile.close();
}
}
private boolean getDistributedUpgradeState() {
FSNamesystem ns = getFSNamesystem();
return ns == null ? false : ns.getDistributedUpgradeState();
}
private int getDistributedUpgradeVersion() {
FSNamesystem ns = getFSNamesystem();
return ns == null ? 0 : ns.getDistributedUpgradeVersion();
}
private void setDistributedUpgradeState(boolean uState, int uVersion) {
getFSNamesystem().upgradeManager.setUpgradeState(uState, uVersion);
}
private void verifyDistributedUpgradeProgress(StartupOption startOpt
) throws IOException {
if(startOpt == StartupOption.ROLLBACK || startOpt == StartupOption.IMPORT)
return;
UpgradeManager um = getFSNamesystem().upgradeManager;
assert um != null : "FSNameSystem.upgradeManager is null.";
if(startOpt != StartupOption.UPGRADE) {
if(um.getUpgradeState())
throw new IOException(
"\n Previous distributed upgrade was not completed. "
+ "\n Please restart NameNode with -upgrade option.");
if(um.getDistributedUpgrades() != null)
throw new IOException("\n Distributed upgrade for NameNode version "
+ um.getUpgradeVersion() + " to current LV " + FSConstants.LAYOUT_VERSION
+ " is required.\n Please restart NameNode with -upgrade option.");
}
}
private void initializeDistributedUpgrade() throws IOException {
UpgradeManagerNamenode um = getFSNamesystem().upgradeManager;
if(! um.initializeUpgrade())
return;
// write new upgrade state into disk
writeAll();
NameNode.LOG.info("\n Distributed upgrade for NameNode version "
+ um.getUpgradeVersion() + " to current LV "
+ FSConstants.LAYOUT_VERSION + " is initialized.");
}
/**
* Retrieve checkpoint dirs from configuration.
*
* @param conf the Configuration
* @param defaultValue a default value for the attribute, if null
* @return a Collection of URIs representing the values in
* fs.checkpoint.dir configuration property
*/
static Collection<URI> getCheckpointDirs(Configuration conf,
String defaultValue) {
Collection<String> dirNames = conf.getStringCollection(DFSConfigKeys.DFS_NAMENODE_CHECKPOINT_DIR_KEY);
if (dirNames.size() == 0 && defaultValue != null) {
dirNames.add(defaultValue);
}
return Util.stringCollectionAsURIs(dirNames);
}
static Collection<URI> getCheckpointEditsDirs(Configuration conf,
String defaultName) {
Collection<String> dirNames =
conf.getStringCollection(DFSConfigKeys.DFS_NAMENODE_CHECKPOINT_EDITS_DIR_KEY);
if (dirNames.size() == 0 && defaultName != null) {
dirNames.add(defaultName);
}
return Util.stringCollectionAsURIs(dirNames);
}
static private final DeprecatedUTF8 U_STR = new DeprecatedUTF8();
// This should be reverted to package private once the ImageLoader
// code is moved into this package. This method should not be called
// by other code.
public static String readString(DataInputStream in) throws IOException {
U_STR.readFields(in);
return U_STR.toString();
}
static String readString_EmptyAsNull(DataInputStream in) throws IOException {
final String s = readString(in);
return s.isEmpty()? null: s;
}
// Same comments apply for this method as for readString()
public static byte[] readBytes(DataInputStream in) throws IOException {
U_STR.readFields(in);
int len = U_STR.getLength();
byte[] bytes = new byte[len];
System.arraycopy(U_STR.getBytes(), 0, bytes, 0, len);
return bytes;
}
static void writeString(String str, DataOutputStream out) throws IOException {
U_STR.set(str);
U_STR.write(out);
}
}