/**
* 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.datanode;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.ComparisonChain;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.common.util.concurrent.Futures;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.FileUtil;
import org.apache.hadoop.fs.HardLink;
import org.apache.hadoop.fs.LocalFileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.permission.FsPermission;
import org.apache.hadoop.hdfs.DFSConfigKeys;
import org.apache.hadoop.hdfs.HdfsConfiguration;
import org.apache.hadoop.hdfs.protocol.Block;
import org.apache.hadoop.hdfs.protocol.LayoutVersion;
import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;
import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.NodeType;
import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.StartupOption;
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.protocol.DatanodeStorage;
import org.apache.hadoop.hdfs.server.protocol.NamespaceInfo;
import org.apache.hadoop.io.nativeio.NativeIO;
import org.apache.hadoop.util.Daemon;
import org.apache.hadoop.util.DiskChecker;
import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.nio.channels.FileLock;
import java.nio.channels.OverlappingFileLockException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
import java.util.TreeMap;
import java.util.concurrent.Callable;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
/**
* Data storage information file.
* <p>
* @see Storage
*/
@InterfaceAudience.Private
public class DataStorage extends Storage {
public final static String BLOCK_SUBDIR_PREFIX = "subdir";
final static String STORAGE_DIR_DETACHED = "detach";
public final static String STORAGE_DIR_RBW = "rbw";
public final static String STORAGE_DIR_FINALIZED = "finalized";
public final static String STORAGE_DIR_LAZY_PERSIST = "lazypersist";
public final static String STORAGE_DIR_TMP = "tmp";
/**
* Set of bpids for which 'trash' is currently enabled.
* When trash is enabled block files are moved under a separate
* 'trash' folder instead of being deleted right away. This can
* be useful during rolling upgrades, for example.
* The set is backed by a concurrent HashMap.
*
* Even if trash is enabled, it is not used if a layout upgrade
* is in progress for a storage directory i.e. if the previous
* directory exists.
*/
private Set<String> trashEnabledBpids;
/**
* Datanode UUID that this storage is currently attached to. This
* is the same as the legacy StorageID for datanodes that were
* upgraded from a pre-UUID version. For compatibility with prior
* versions of Datanodes we cannot make this field a UUID.
*/
private String datanodeUuid = null;
// Flag to ensure we only initialize storage once
private boolean initialized = false;
// Maps block pool IDs to block pool storage
private final Map<String, BlockPoolSliceStorage> bpStorageMap
= Collections.synchronizedMap(new HashMap<String, BlockPoolSliceStorage>());
DataStorage() {
super(NodeType.DATA_NODE);
trashEnabledBpids = Collections.newSetFromMap(
new ConcurrentHashMap<String, Boolean>());
}
public BlockPoolSliceStorage getBPStorage(String bpid) {
return bpStorageMap.get(bpid);
}
public DataStorage(StorageInfo storageInfo) {
super(storageInfo);
}
public synchronized String getDatanodeUuid() {
return datanodeUuid;
}
public synchronized void setDatanodeUuid(String newDatanodeUuid) {
this.datanodeUuid = newDatanodeUuid;
}
/** Create an ID for this storage.
* @return true if a new storage ID was generated.
* */
public synchronized boolean createStorageID(
StorageDirectory sd, boolean regenerateStorageIds) {
final String oldStorageID = sd.getStorageUuid();
if (oldStorageID == null || regenerateStorageIds) {
sd.setStorageUuid(DatanodeStorage.generateUuid());
LOG.info("Generated new storageID " + sd.getStorageUuid() +
" for directory " + sd.getRoot() +
(oldStorageID == null ? "" : (" to replace " + oldStorageID)));
return true;
}
return false;
}
/**
* Enable trash for the specified block pool storage. Even if trash is
* enabled by the caller, it is superseded by the 'previous' directory
* if a layout upgrade is in progress.
*/
public void enableTrash(String bpid) {
if (trashEnabledBpids.add(bpid)) {
LOG.info("Enabled trash for bpid " + bpid);
}
}
public void clearTrash(String bpid) {
if (trashEnabledBpids.contains(bpid)) {
getBPStorage(bpid).clearTrash();
trashEnabledBpids.remove(bpid);
LOG.info("Cleared trash for bpid " + bpid);
}
}
public boolean trashEnabled(String bpid) {
return trashEnabledBpids.contains(bpid);
}
public void setRollingUpgradeMarker(String bpid) throws IOException {
getBPStorage(bpid).setRollingUpgradeMarkers(storageDirs);
}
public void clearRollingUpgradeMarker(String bpid) throws IOException {
getBPStorage(bpid).clearRollingUpgradeMarkers(storageDirs);
}
/**
* If rolling upgrades are in progress then do not delete block files
* immediately. Instead we move the block files to an intermediate
* 'trash' directory. If there is a subsequent rollback, then the block
* files will be restored from trash.
*
* @return trash directory if rolling upgrade is in progress, null
* otherwise.
*/
public String getTrashDirectoryForBlockFile(String bpid, File blockFile) {
if (trashEnabledBpids.contains(bpid)) {
return getBPStorage(bpid).getTrashDirectory(blockFile);
}
return null;
}
/**
* VolumeBuilder holds the metadata (e.g., the storage directories) of the
* prepared volume returned from {@link prepareVolume()}. Calling {@link build()}
* to add the metadata to {@link DataStorage} so that this prepared volume can
* be active.
*/
@InterfaceAudience.Private
@InterfaceStability.Unstable
static public class VolumeBuilder {
private DataStorage storage;
/** Volume level storage directory. */
private StorageDirectory sd;
/** Mapping from block pool ID to an array of storage directories. */
private Map<String, List<StorageDirectory>> bpStorageDirMap =
Maps.newHashMap();
@VisibleForTesting
public VolumeBuilder(DataStorage storage, StorageDirectory sd) {
this.storage = storage;
this.sd = sd;
}
public final StorageDirectory getStorageDirectory() {
return this.sd;
}
private void addBpStorageDirectories(String bpid,
List<StorageDirectory> dirs) {
bpStorageDirMap.put(bpid, dirs);
}
/**
* Add loaded metadata of a data volume to {@link DataStorage}.
*/
public void build() {
assert this.sd != null;
synchronized (storage) {
for (Map.Entry<String, List<StorageDirectory>> e :
bpStorageDirMap.entrySet()) {
final String bpid = e.getKey();
BlockPoolSliceStorage bpStorage = this.storage.bpStorageMap.get(bpid);
assert bpStorage != null;
for (StorageDirectory bpSd : e.getValue()) {
bpStorage.addStorageDir(bpSd);
}
}
storage.addStorageDir(sd);
}
}
}
private StorageDirectory loadStorageDirectory(DataNode datanode,
NamespaceInfo nsInfo, File dataDir, StartupOption startOpt)
throws IOException {
StorageDirectory sd = new StorageDirectory(dataDir, null, false);
try {
StorageState curState = sd.analyzeStorage(startOpt, this);
// sd is locked but not opened
switch (curState) {
case NORMAL:
break;
case NON_EXISTENT:
LOG.info("Storage directory " + dataDir + " does not exist");
throw new IOException("Storage directory " + dataDir
+ " does not exist");
case NOT_FORMATTED: // format
LOG.info("Storage directory " + dataDir + " is not formatted for "
+ nsInfo.getBlockPoolID());
LOG.info("Formatting ...");
format(sd, nsInfo, datanode.getDatanodeUuid());
break;
default: // recovery part is common
sd.doRecover(curState);
}
// 2. Do transitions
// Each storage directory is treated individually.
// During startup some of them can upgrade or roll back
// while others could be up-to-date for the regular startup.
doTransition(datanode, sd, nsInfo, startOpt);
// 3. Update successfully loaded storage.
setServiceLayoutVersion(getServiceLayoutVersion());
writeProperties(sd);
return sd;
} catch (IOException ioe) {
sd.unlock();
throw ioe;
}
}
/**
* Prepare a storage directory. It creates a builder which can be used to add
* to the volume. If the volume cannot be added, it is OK to discard the
* builder later.
*
* @param datanode DataNode object.
* @param volume the root path of a storage directory.
* @param nsInfos an array of namespace infos.
* @return a VolumeBuilder that holds the metadata of this storage directory
* and can be added to DataStorage later.
* @throws IOException if encounters I/O errors.
*
* Note that if there is IOException, the state of DataStorage is not modified.
*/
public VolumeBuilder prepareVolume(DataNode datanode, File volume,
List<NamespaceInfo> nsInfos) throws IOException {
if (containsStorageDir(volume)) {
final String errorMessage = "Storage directory is in use";
LOG.warn(errorMessage + ".");
throw new IOException(errorMessage);
}
StorageDirectory sd = loadStorageDirectory(
datanode, nsInfos.get(0), volume, StartupOption.HOTSWAP);
VolumeBuilder builder =
new VolumeBuilder(this, sd);
for (NamespaceInfo nsInfo : nsInfos) {
List<File> bpDataDirs = Lists.newArrayList();
bpDataDirs.add(BlockPoolSliceStorage.getBpRoot(
nsInfo.getBlockPoolID(), new File(volume, STORAGE_DIR_CURRENT)));
makeBlockPoolDataDir(bpDataDirs, null);
BlockPoolSliceStorage bpStorage;
final String bpid = nsInfo.getBlockPoolID();
synchronized (this) {
bpStorage = this.bpStorageMap.get(bpid);
if (bpStorage == null) {
bpStorage = new BlockPoolSliceStorage(
nsInfo.getNamespaceID(), bpid, nsInfo.getCTime(),
nsInfo.getClusterID());
addBlockPoolStorage(bpid, bpStorage);
}
}
builder.addBpStorageDirectories(
bpid, bpStorage.loadBpStorageDirectories(
datanode, nsInfo, bpDataDirs, StartupOption.HOTSWAP));
}
return builder;
}
/**
* Add a list of volumes to be managed by DataStorage. If the volume is empty,
* format it, otherwise recover it from previous transitions if required.
*
* @param datanode the reference to DataNode.
* @param nsInfo namespace information
* @param dataDirs array of data storage directories
* @param startOpt startup option
* @return a list of successfully loaded volumes.
* @throws IOException
*/
@VisibleForTesting
synchronized List<StorageLocation> addStorageLocations(DataNode datanode,
NamespaceInfo nsInfo, Collection<StorageLocation> dataDirs,
StartupOption startOpt) throws IOException {
final String bpid = nsInfo.getBlockPoolID();
List<StorageLocation> successVolumes = Lists.newArrayList();
for (StorageLocation dataDir : dataDirs) {
File root = dataDir.getFile();
if (!containsStorageDir(root)) {
try {
// It first ensures the datanode level format is completed.
StorageDirectory sd = loadStorageDirectory(
datanode, nsInfo, root, startOpt);
addStorageDir(sd);
} catch (IOException e) {
LOG.warn(e);
continue;
}
} else {
LOG.info("Storage directory " + dataDir + " has already been used.");
}
List<File> bpDataDirs = new ArrayList<File>();
bpDataDirs.add(BlockPoolSliceStorage.getBpRoot(bpid, new File(root,
STORAGE_DIR_CURRENT)));
try {
makeBlockPoolDataDir(bpDataDirs, null);
BlockPoolSliceStorage bpStorage = this.bpStorageMap.get(bpid);
if (bpStorage == null) {
bpStorage = new BlockPoolSliceStorage(
nsInfo.getNamespaceID(), bpid, nsInfo.getCTime(),
nsInfo.getClusterID());
}
bpStorage.recoverTransitionRead(datanode, nsInfo, bpDataDirs, startOpt);
addBlockPoolStorage(bpid, bpStorage);
} catch (IOException e) {
LOG.warn("Failed to add storage for block pool: " + bpid + " : "
+ e.getMessage());
continue;
}
successVolumes.add(dataDir);
}
return successVolumes;
}
/**
* Remove storage dirs from DataStorage. All storage dirs are removed even when the
* IOException is thrown.
*
* @param dirsToRemove a set of storage directories to be removed.
* @throws IOException if I/O error when unlocking storage directory.
*/
synchronized void removeVolumes(final Set<File> dirsToRemove)
throws IOException {
if (dirsToRemove.isEmpty()) {
return;
}
StringBuilder errorMsgBuilder = new StringBuilder();
for (Iterator<StorageDirectory> it = this.storageDirs.iterator();
it.hasNext(); ) {
StorageDirectory sd = it.next();
if (dirsToRemove.contains(sd.getRoot())) {
// Remove the block pool level storage first.
for (Map.Entry<String, BlockPoolSliceStorage> entry :
this.bpStorageMap.entrySet()) {
String bpid = entry.getKey();
BlockPoolSliceStorage bpsStorage = entry.getValue();
File bpRoot =
BlockPoolSliceStorage.getBpRoot(bpid, sd.getCurrentDir());
bpsStorage.remove(bpRoot.getAbsoluteFile());
}
it.remove();
try {
sd.unlock();
} catch (IOException e) {
LOG.warn(String.format(
"I/O error attempting to unlock storage directory %s.",
sd.getRoot()), e);
errorMsgBuilder.append(String.format("Failed to remove %s: %s%n",
sd.getRoot(), e.getMessage()));
}
}
}
if (errorMsgBuilder.length() > 0) {
throw new IOException(errorMsgBuilder.toString());
}
}
/**
* Analyze storage directories for a specific block pool.
* Recover from previous transitions if required.
* Perform fs state transition if necessary depending on the namespace info.
* Read storage info.
* <br>
* This method should be synchronized between multiple DN threads. Only the
* first DN thread does DN level storage dir recoverTransitionRead.
*
* @param datanode DataNode
* @param nsInfo Namespace info of namenode corresponding to the block pool
* @param dataDirs Storage directories
* @param startOpt startup option
* @throws IOException on error
*/
void recoverTransitionRead(DataNode datanode, NamespaceInfo nsInfo,
Collection<StorageLocation> dataDirs, StartupOption startOpt) throws IOException {
if (this.initialized) {
LOG.info("DataNode version: " + HdfsServerConstants.DATANODE_LAYOUT_VERSION
+ " and NameNode layout version: " + nsInfo.getLayoutVersion());
this.storageDirs = new ArrayList<StorageDirectory>(dataDirs.size());
// mark DN storage is initialized
this.initialized = true;
}
if (addStorageLocations(datanode, nsInfo, dataDirs, startOpt).isEmpty()) {
throw new IOException("All specified directories are failed to load.");
}
}
/**
* Create physical directory for block pools on the data node
*
* @param dataDirs
* List of data directories
* @param conf
* Configuration instance to use.
* @throws IOException on errors
*/
static void makeBlockPoolDataDir(Collection<File> dataDirs,
Configuration conf) throws IOException {
if (conf == null)
conf = new HdfsConfiguration();
LocalFileSystem localFS = FileSystem.getLocal(conf);
FsPermission permission = new FsPermission(conf.get(
DFSConfigKeys.DFS_DATANODE_DATA_DIR_PERMISSION_KEY,
DFSConfigKeys.DFS_DATANODE_DATA_DIR_PERMISSION_DEFAULT));
for (File data : dataDirs) {
try {
DiskChecker.checkDir(localFS, new Path(data.toURI()), permission);
} catch ( IOException e ) {
LOG.warn("Invalid directory in: " + data.getCanonicalPath() + ": "
+ e.getMessage());
}
}
}
void format(StorageDirectory sd, NamespaceInfo nsInfo,
String datanodeUuid) throws IOException {
sd.clearDirectory(); // create directory
this.layoutVersion = HdfsServerConstants.DATANODE_LAYOUT_VERSION;
this.clusterID = nsInfo.getClusterID();
this.namespaceID = nsInfo.getNamespaceID();
this.cTime = 0;
setDatanodeUuid(datanodeUuid);
if (sd.getStorageUuid() == null) {
// Assign a new Storage UUID.
sd.setStorageUuid(DatanodeStorage.generateUuid());
}
writeProperties(sd);
}
/*
* Set ClusterID, StorageID, StorageType, CTime into
* DataStorage VERSION file.
* Always called just before writing the properties to
* the VERSION file.
*/
@Override
protected void setPropertiesFromFields(Properties props,
StorageDirectory sd
) throws IOException {
props.setProperty("storageType", storageType.toString());
props.setProperty("clusterID", clusterID);
props.setProperty("cTime", String.valueOf(cTime));
props.setProperty("layoutVersion", String.valueOf(layoutVersion));
props.setProperty("storageID", sd.getStorageUuid());
String datanodeUuid = getDatanodeUuid();
if (datanodeUuid != null) {
props.setProperty("datanodeUuid", datanodeUuid);
}
// Set NamespaceID in version before federation
if (!DataNodeLayoutVersion.supports(
LayoutVersion.Feature.FEDERATION, layoutVersion)) {
props.setProperty("namespaceID", String.valueOf(namespaceID));
}
}
/*
* Read ClusterID, StorageID, StorageType, CTime from
* DataStorage VERSION file and verify them.
* Always called just after reading the properties from the VERSION file.
*/
@Override
protected void setFieldsFromProperties(Properties props, StorageDirectory sd)
throws IOException {
setFieldsFromProperties(props, sd, false, 0);
}
private void setFieldsFromProperties(Properties props, StorageDirectory sd,
boolean overrideLayoutVersion, int toLayoutVersion) throws IOException {
if (overrideLayoutVersion) {
this.layoutVersion = toLayoutVersion;
} else {
setLayoutVersion(props, sd);
}
setcTime(props, sd);
checkStorageType(props, sd);
setClusterId(props, layoutVersion, sd);
// Read NamespaceID in version before federation
if (!DataNodeLayoutVersion.supports(
LayoutVersion.Feature.FEDERATION, layoutVersion)) {
setNamespaceID(props, sd);
}
// valid storage id, storage id may be empty
String ssid = props.getProperty("storageID");
if (ssid == null) {
throw new InconsistentFSStateException(sd.getRoot(), "file "
+ STORAGE_FILE_VERSION + " is invalid.");
}
String sid = sd.getStorageUuid();
if (!(sid == null || sid.equals("") ||
ssid.equals("") || sid.equals(ssid))) {
throw new InconsistentFSStateException(sd.getRoot(),
"has incompatible storage Id.");
}
if (sid == null) { // update id only if it was null
sd.setStorageUuid(ssid);
}
// Update the datanode UUID if present.
if (props.getProperty("datanodeUuid") != null) {
String dnUuid = props.getProperty("datanodeUuid");
if (getDatanodeUuid() == null) {
setDatanodeUuid(dnUuid);
} else if (getDatanodeUuid().compareTo(dnUuid) != 0) {
throw new InconsistentFSStateException(sd.getRoot(),
"Root " + sd.getRoot() + ": DatanodeUuid=" + dnUuid +
", does not match " + getDatanodeUuid() + " from other" +
" StorageDirectory.");
}
}
}
@Override
public boolean isPreUpgradableLayout(StorageDirectory sd) throws IOException {
File oldF = new File(sd.getRoot(), "storage");
if (!oldF.exists()) {
return false;
}
// check the layout version inside the storage file
// Lock and Read old storage file
try (RandomAccessFile oldFile = new RandomAccessFile(oldF, "rws");
FileLock oldLock = oldFile.getChannel().tryLock()) {
if (null == oldLock) {
LOG.error("Unable to acquire file lock on path " + oldF.toString());
throw new OverlappingFileLockException();
}
oldFile.seek(0);
int oldVersion = oldFile.readInt();
if (oldVersion < LAST_PRE_UPGRADE_LAYOUT_VERSION) {
return false;
}
}
return true;
}
/** Read VERSION file for rollback */
void readProperties(StorageDirectory sd, int rollbackLayoutVersion)
throws IOException {
Properties props = readPropertiesFile(sd.getVersionFile());
setFieldsFromProperties(props, sd, true, rollbackLayoutVersion);
}
/**
* Analize which and whether a transition of the fs state is required
* and perform it if necessary.
*
* Rollback if the rollback startup option was specified.
* Upgrade if this.LV > LAYOUT_VERSION
* Regular startup if this.LV = LAYOUT_VERSION
*
* @param datanode Datanode to which this storage belongs to
* @param sd storage directory
* @param nsInfo namespace info
* @param startOpt startup option
* @throws IOException
*/
private void doTransition( DataNode datanode,
StorageDirectory sd,
NamespaceInfo nsInfo,
StartupOption startOpt
) throws IOException {
if (startOpt == StartupOption.ROLLBACK) {
doRollback(sd, nsInfo); // rollback if applicable
}
readProperties(sd);
checkVersionUpgradable(this.layoutVersion);
assert this.layoutVersion >= HdfsServerConstants.DATANODE_LAYOUT_VERSION :
"Future version is not allowed";
boolean federationSupported =
DataNodeLayoutVersion.supports(
LayoutVersion.Feature.FEDERATION, layoutVersion);
// For pre-federation version - validate the namespaceID
if (!federationSupported &&
getNamespaceID() != nsInfo.getNamespaceID()) {
throw new IOException("Incompatible namespaceIDs in "
+ sd.getRoot().getCanonicalPath() + ": namenode namespaceID = "
+ nsInfo.getNamespaceID() + "; datanode namespaceID = "
+ getNamespaceID());
}
// For version that supports federation, validate clusterID
if (federationSupported
&& !getClusterID().equals(nsInfo.getClusterID())) {
throw new IOException("Incompatible clusterIDs in "
+ sd.getRoot().getCanonicalPath() + ": namenode clusterID = "
+ nsInfo.getClusterID() + "; datanode clusterID = " + getClusterID());
}
// Clusters previously upgraded from layout versions earlier than
// ADD_DATANODE_AND_STORAGE_UUIDS failed to correctly generate a
// new storage ID. We check for that and fix it now.
boolean haveValidStorageId =
DataNodeLayoutVersion.supports(
LayoutVersion.Feature.ADD_DATANODE_AND_STORAGE_UUIDS, layoutVersion) &&
DatanodeStorage.isValidStorageId(sd.getStorageUuid());
// regular start up.
if (this.layoutVersion == HdfsServerConstants.DATANODE_LAYOUT_VERSION) {
createStorageID(sd, !haveValidStorageId);
return; // regular startup
}
// do upgrade
if (this.layoutVersion > HdfsServerConstants.DATANODE_LAYOUT_VERSION) {
doUpgrade(datanode, sd, nsInfo); // upgrade
createStorageID(sd, !haveValidStorageId);
return;
}
// layoutVersion < DATANODE_LAYOUT_VERSION. I.e. stored layout version is newer
// than the version supported by datanode. This should have been caught
// in readProperties(), even if rollback was not carried out or somehow
// failed.
throw new IOException("BUG: The stored LV = " + this.getLayoutVersion()
+ " is newer than the supported LV = "
+ HdfsServerConstants.DATANODE_LAYOUT_VERSION);
}
/**
* Upgrade -- Move current storage into a backup directory,
* and hardlink all its blocks into the new current directory.
*
* Upgrade from pre-0.22 to 0.22 or later release e.g. 0.19/0.20/ => 0.22/0.23
* <ul>
* <li> If <SD>/previous exists then delete it </li>
* <li> Rename <SD>/current to <SD>/previous.tmp </li>
* <li>Create new <SD>/current/<bpid>/current directory<li>
* <ul>
* <li> Hard links for block files are created from <SD>/previous.tmp
* to <SD>/current/<bpid>/current </li>
* <li> Saves new version file in <SD>/current/<bpid>/current directory </li>
* </ul>
* <li> Rename <SD>/previous.tmp to <SD>/previous </li>
* </ul>
*
* There should be only ONE namenode in the cluster for first
* time upgrade to 0.22
* @param sd storage directory
* @throws IOException on error
*/
void doUpgrade(DataNode datanode, StorageDirectory sd, NamespaceInfo nsInfo)
throws IOException {
// If the existing on-disk layout version supportes federation, simply
// update its layout version.
if (DataNodeLayoutVersion.supports(
LayoutVersion.Feature.FEDERATION, layoutVersion)) {
// The VERSION file is already read in. Override the layoutVersion
// field and overwrite the file. The upgrade work is handled by
// {@link BlockPoolSliceStorage#doUpgrade}
LOG.info("Updating layout version from " + layoutVersion + " to "
+ HdfsServerConstants.DATANODE_LAYOUT_VERSION + " for storage "
+ sd.getRoot());
layoutVersion = HdfsServerConstants.DATANODE_LAYOUT_VERSION;
writeProperties(sd);
return;
}
LOG.info("Upgrading storage directory " + sd.getRoot()
+ ".\n old LV = " + this.getLayoutVersion()
+ "; old CTime = " + this.getCTime()
+ ".\n new LV = " + HdfsServerConstants.DATANODE_LAYOUT_VERSION
+ "; new CTime = " + nsInfo.getCTime());
File curDir = sd.getCurrentDir();
File prevDir = sd.getPreviousDir();
File bbwDir = new File(sd.getRoot(), Storage.STORAGE_1_BBW);
assert curDir.exists() : "Data node current directory must exist.";
// Cleanup directory "detach"
cleanupDetachDir(new File(curDir, STORAGE_DIR_DETACHED));
// 1. delete <SD>/previous dir before upgrading
if (prevDir.exists())
deleteDir(prevDir);
// get previous.tmp directory, <SD>/previous.tmp
File tmpDir = sd.getPreviousTmp();
assert !tmpDir.exists() :
"Data node previous.tmp directory must not exist.";
// 2. Rename <SD>/current to <SD>/previous.tmp
rename(curDir, tmpDir);
// 3. Format BP and hard link blocks from previous directory
File curBpDir = BlockPoolSliceStorage.getBpRoot(nsInfo.getBlockPoolID(), curDir);
BlockPoolSliceStorage bpStorage = new BlockPoolSliceStorage(nsInfo.getNamespaceID(),
nsInfo.getBlockPoolID(), nsInfo.getCTime(), nsInfo.getClusterID());
bpStorage.format(curDir, nsInfo);
linkAllBlocks(datanode, tmpDir, bbwDir, new File(curBpDir,
STORAGE_DIR_CURRENT));
// 4. Write version file under <SD>/current
layoutVersion = HdfsServerConstants.DATANODE_LAYOUT_VERSION;
clusterID = nsInfo.getClusterID();
writeProperties(sd);
// 5. Rename <SD>/previous.tmp to <SD>/previous
rename(tmpDir, prevDir);
LOG.info("Upgrade of " + sd.getRoot()+ " is complete");
addBlockPoolStorage(nsInfo.getBlockPoolID(), bpStorage);
}
/**
* Cleanup the detachDir.
*
* If the directory is not empty report an error;
* Otherwise remove the directory.
*
* @param detachDir detach directory
* @throws IOException if the directory is not empty or it can not be removed
*/
private void cleanupDetachDir(File detachDir) throws IOException {
if (!DataNodeLayoutVersion.supports(
LayoutVersion.Feature.APPEND_RBW_DIR, layoutVersion) &&
detachDir.exists() && detachDir.isDirectory() ) {
if (FileUtil.list(detachDir).length != 0 ) {
throw new IOException("Detached directory " + detachDir +
" is not empty. Please manually move each file under this " +
"directory to the finalized directory if the finalized " +
"directory tree does not have the file.");
} else if (!detachDir.delete()) {
throw new IOException("Cannot remove directory " + detachDir);
}
}
}
/**
* Rolling back to a snapshot in previous directory by moving it to current
* directory.
* Rollback procedure:
* <br>
* If previous directory exists:
* <ol>
* <li> Rename current to removed.tmp </li>
* <li> Rename previous to current </li>
* <li> Remove removed.tmp </li>
* </ol>
*
* If previous directory does not exist and the current version supports
* federation, perform a simple rollback of layout version. This does not
* involve saving/restoration of actual data.
*/
void doRollback( StorageDirectory sd,
NamespaceInfo nsInfo
) throws IOException {
File prevDir = sd.getPreviousDir();
// This is a regular startup or a post-federation rollback
if (!prevDir.exists()) {
if (DataNodeLayoutVersion.supports(LayoutVersion.Feature.FEDERATION,
HdfsServerConstants.DATANODE_LAYOUT_VERSION)) {
readProperties(sd, HdfsServerConstants.DATANODE_LAYOUT_VERSION);
writeProperties(sd);
LOG.info("Layout version rolled back to "
+ HdfsServerConstants.DATANODE_LAYOUT_VERSION + " for storage "
+ sd.getRoot());
}
return;
}
DataStorage prevInfo = new DataStorage();
prevInfo.readPreviousVersionProperties(sd);
// We allow rollback to a state, which is either consistent with
// the namespace state or can be further upgraded to it.
if (!(prevInfo.getLayoutVersion() >= HdfsServerConstants.DATANODE_LAYOUT_VERSION
&& prevInfo.getCTime() <= nsInfo.getCTime())) // cannot rollback
throw new InconsistentFSStateException(sd.getRoot(),
"Cannot rollback to a newer state.\nDatanode previous state: LV = "
+ prevInfo.getLayoutVersion() + " CTime = " + prevInfo.getCTime()
+ " is newer than the namespace state: LV = "
+ HdfsServerConstants.DATANODE_LAYOUT_VERSION + " CTime = "
+ nsInfo.getCTime());
LOG.info("Rolling back storage directory " + sd.getRoot()
+ ".\n target LV = " + HdfsServerConstants.DATANODE_LAYOUT_VERSION
+ "; target CTime = " + nsInfo.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");
}
/**
* Finalize procedure deletes an existing snapshot.
* <ol>
* <li>Rename previous to finalized.tmp directory</li>
* <li>Fully delete the finalized.tmp directory</li>
* </ol>
*
* Do nothing, if previous directory does not exist
*/
void doFinalize(StorageDirectory sd) throws IOException {
File prevDir = sd.getPreviousDir();
if (!prevDir.exists())
return; // already discarded
final String dataDirPath = sd.getRoot().getCanonicalPath();
LOG.info("Finalizing upgrade for storage directory "
+ dataDirPath
+ ".\n cur LV = " + this.getLayoutVersion()
+ "; cur CTime = " + this.getCTime());
assert sd.getCurrentDir().exists() : "Current directory must exist.";
final File tmpDir = sd.getFinalizedTmp();//finalized.tmp directory
final File bbwDir = new File(sd.getRoot(), Storage.STORAGE_1_BBW);
// 1. rename previous to finalized.tmp
rename(prevDir, tmpDir);
// 2. delete finalized.tmp dir in a separate thread
// Also delete the blocksBeingWritten from HDFS 1.x and earlier, if
// it exists.
new Daemon(new Runnable() {
@Override
public void run() {
try {
deleteDir(tmpDir);
if (bbwDir.exists()) {
deleteDir(bbwDir);
}
} catch(IOException ex) {
LOG.error("Finalize upgrade for " + dataDirPath + " failed", ex);
}
LOG.info("Finalize upgrade for " + dataDirPath + " is complete");
}
@Override
public String toString() { return "Finalize " + dataDirPath; }
}).start();
}
/*
* Finalize the upgrade for a block pool
* This also empties trash created during rolling upgrade and disables
* trash functionality.
*/
void finalizeUpgrade(String bpID) throws IOException {
// To handle finalizing a snapshot taken at datanode level while
// upgrading to federation, if datanode level snapshot previous exists,
// then finalize it. Else finalize the corresponding BP.
for (StorageDirectory sd : storageDirs) {
File prevDir = sd.getPreviousDir();
if (prevDir.exists()) {
// data node level storage finalize
doFinalize(sd);
} else {
// block pool storage finalize using specific bpID
BlockPoolSliceStorage bpStorage = bpStorageMap.get(bpID);
bpStorage.doFinalize(sd.getCurrentDir());
}
}
}
/**
* Hardlink all finalized and RBW blocks in fromDir to toDir
*
* @param fromDir The directory where the 'from' snapshot is stored
* @param fromBbwDir In HDFS 1.x, the directory where blocks
* that are under construction are stored.
* @param toDir The current data directory
*
* @throws IOException If error occurs during hardlink
*/
private void linkAllBlocks(DataNode datanode, File fromDir, File fromBbwDir,
File toDir) throws IOException {
HardLink hardLink = new HardLink();
// do the link
int diskLayoutVersion = this.getLayoutVersion();
if (DataNodeLayoutVersion.supports(
LayoutVersion.Feature.APPEND_RBW_DIR, diskLayoutVersion)) {
// hardlink finalized blocks in tmpDir/finalized
linkBlocks(datanode, new File(fromDir, STORAGE_DIR_FINALIZED),
new File(toDir, STORAGE_DIR_FINALIZED), diskLayoutVersion, hardLink);
// hardlink rbw blocks in tmpDir/rbw
linkBlocks(datanode, new File(fromDir, STORAGE_DIR_RBW),
new File(toDir, STORAGE_DIR_RBW), diskLayoutVersion, hardLink);
} else { // pre-RBW version
// hardlink finalized blocks in tmpDir
linkBlocks(datanode, fromDir, new File(toDir, STORAGE_DIR_FINALIZED),
diskLayoutVersion, hardLink);
if (fromBbwDir.exists()) {
/*
* We need to put the 'blocksBeingWritten' from HDFS 1.x into the rbw
* directory. It's a little messy, because the blocksBeingWriten was
* NOT underneath the 'current' directory in those releases. See
* HDFS-3731 for details.
*/
linkBlocks(datanode, fromBbwDir,
new File(toDir, STORAGE_DIR_RBW), diskLayoutVersion, hardLink);
}
}
LOG.info( hardLink.linkStats.report() );
}
private static class LinkArgs {
File src;
File dst;
LinkArgs(File src, File dst) {
this.src = src;
this.dst = dst;
}
}
static void linkBlocks(DataNode datanode, File from, File to, int oldLV,
HardLink hl) throws IOException {
boolean upgradeToIdBasedLayout = false;
// If we are upgrading from a version older than the one where we introduced
// block ID-based layout AND we're working with the finalized directory,
// we'll need to upgrade from the old flat layout to the block ID-based one
if (oldLV > DataNodeLayoutVersion.Feature.BLOCKID_BASED_LAYOUT.getInfo().
getLayoutVersion() && to.getName().equals(STORAGE_DIR_FINALIZED)) {
upgradeToIdBasedLayout = true;
}
final ArrayList<LinkArgs> idBasedLayoutSingleLinks = Lists.newArrayList();
linkBlocksHelper(from, to, oldLV, hl, upgradeToIdBasedLayout, to,
idBasedLayoutSingleLinks);
// Detect and remove duplicate entries.
final ArrayList<LinkArgs> duplicates =
findDuplicateEntries(idBasedLayoutSingleLinks);
if (!duplicates.isEmpty()) {
LOG.error("There are " + duplicates.size() + " duplicate block " +
"entries within the same volume.");
removeDuplicateEntries(idBasedLayoutSingleLinks, duplicates);
}
int numLinkWorkers = datanode.getConf().getInt(
DFSConfigKeys.DFS_DATANODE_BLOCK_ID_LAYOUT_UPGRADE_THREADS_KEY,
DFSConfigKeys.DFS_DATANODE_BLOCK_ID_LAYOUT_UPGRADE_THREADS);
ExecutorService linkWorkers = Executors.newFixedThreadPool(numLinkWorkers);
final int step = idBasedLayoutSingleLinks.size() / numLinkWorkers + 1;
List<Future<Void>> futures = Lists.newArrayList();
for (int i = 0; i < idBasedLayoutSingleLinks.size(); i += step) {
final int iCopy = i;
futures.add(linkWorkers.submit(new Callable<Void>() {
@Override
public Void call() throws IOException {
int upperBound = Math.min(iCopy + step,
idBasedLayoutSingleLinks.size());
for (int j = iCopy; j < upperBound; j++) {
LinkArgs cur = idBasedLayoutSingleLinks.get(j);
HardLink.createHardLink(cur.src, cur.dst);
}
return null;
}
}));
}
linkWorkers.shutdown();
for (Future<Void> f : futures) {
Futures.get(f, IOException.class);
}
}
/**
* Find duplicate entries with an array of LinkArgs.
* Duplicate entries are entries with the same last path component.
*/
static ArrayList<LinkArgs> findDuplicateEntries(ArrayList<LinkArgs> all) {
// Find duplicates by sorting the list by the final path component.
Collections.sort(all, new Comparator<LinkArgs>() {
/**
* Compare two LinkArgs objects, such that objects with the same
* terminal source path components are grouped together.
*/
@Override
public int compare(LinkArgs a, LinkArgs b) {
return ComparisonChain.start().
compare(a.src.getName(), b.src.getName()).
compare(a.src, b.src).
compare(a.dst, b.dst).
result();
}
});
final ArrayList<LinkArgs> duplicates = Lists.newArrayList();
Long prevBlockId = null;
boolean prevWasMeta = false;
boolean addedPrev = false;
for (int i = 0; i < all.size(); i++) {
LinkArgs args = all.get(i);
long blockId = Block.getBlockId(args.src.getName());
boolean isMeta = Block.isMetaFilename(args.src.getName());
if ((prevBlockId == null) ||
(prevBlockId.longValue() != blockId)) {
prevBlockId = blockId;
addedPrev = false;
} else if (isMeta == prevWasMeta) {
// If we saw another file for the same block ID previously,
// and it had the same meta-ness as this file, we have a
// duplicate.
duplicates.add(args);
if (!addedPrev) {
duplicates.add(all.get(i - 1));
}
addedPrev = true;
} else {
addedPrev = false;
}
prevWasMeta = isMeta;
}
return duplicates;
}
/**
* Remove duplicate entries from the list.
* We do this by choosing:
* 1. the entries with the highest genstamp (this takes priority),
* 2. the entries with the longest block files,
* 3. arbitrarily, if neither #1 nor #2 gives a clear winner.
*
* Block and metadata files form a pair-- if you take a metadata file from
* one subdirectory, you must also take the block file from that
* subdirectory.
*/
private static void removeDuplicateEntries(ArrayList<LinkArgs> all,
ArrayList<LinkArgs> duplicates) {
// Maps blockId -> metadata file with highest genstamp
TreeMap<Long, List<LinkArgs>> highestGenstamps =
new TreeMap<Long, List<LinkArgs>>();
for (LinkArgs duplicate : duplicates) {
if (!Block.isMetaFilename(duplicate.src.getName())) {
continue;
}
long blockId = Block.getBlockId(duplicate.src.getName());
List<LinkArgs> prevHighest = highestGenstamps.get(blockId);
if (prevHighest == null) {
List<LinkArgs> highest = new LinkedList<LinkArgs>();
highest.add(duplicate);
highestGenstamps.put(blockId, highest);
continue;
}
long prevGenstamp =
Block.getGenerationStamp(prevHighest.get(0).src.getName());
long genstamp = Block.getGenerationStamp(duplicate.src.getName());
if (genstamp < prevGenstamp) {
continue;
}
if (genstamp > prevGenstamp) {
prevHighest.clear();
}
prevHighest.add(duplicate);
}
// Remove data / metadata entries that don't have the highest genstamp
// from the duplicates list.
for (Iterator<LinkArgs> iter = duplicates.iterator(); iter.hasNext(); ) {
LinkArgs duplicate = iter.next();
long blockId = Block.getBlockId(duplicate.src.getName());
List<LinkArgs> highest = highestGenstamps.get(blockId);
if (highest != null) {
boolean found = false;
for (LinkArgs high : highest) {
if (high.src.getParent().equals(duplicate.src.getParent())) {
found = true;
break;
}
}
if (!found) {
LOG.warn("Unexpectedly low genstamp on " +
duplicate.src.getAbsolutePath() + ".");
iter.remove();
}
}
}
// Find the longest block files
// We let the "last guy win" here, since we're only interested in
// preserving one block file / metadata file pair.
TreeMap<Long, LinkArgs> longestBlockFiles = new TreeMap<Long, LinkArgs>();
for (LinkArgs duplicate : duplicates) {
if (Block.isMetaFilename(duplicate.src.getName())) {
continue;
}
long blockId = Block.getBlockId(duplicate.src.getName());
LinkArgs prevLongest = longestBlockFiles.get(blockId);
if (prevLongest == null) {
longestBlockFiles.put(blockId, duplicate);
continue;
}
long blockLength = duplicate.src.length();
long prevBlockLength = prevLongest.src.length();
if (blockLength < prevBlockLength) {
LOG.warn("Unexpectedly short length on " +
duplicate.src.getAbsolutePath() + ".");
continue;
}
if (blockLength > prevBlockLength) {
LOG.warn("Unexpectedly short length on " +
prevLongest.src.getAbsolutePath() + ".");
}
longestBlockFiles.put(blockId, duplicate);
}
// Remove data / metadata entries that aren't the longest, or weren't
// arbitrarily selected by us.
for (Iterator<LinkArgs> iter = all.iterator(); iter.hasNext(); ) {
LinkArgs args = iter.next();
long blockId = Block.getBlockId(args.src.getName());
LinkArgs bestDuplicate = longestBlockFiles.get(blockId);
if (bestDuplicate == null) {
continue; // file has no duplicates
}
if (!bestDuplicate.src.getParent().equals(args.src.getParent())) {
LOG.warn("Discarding " + args.src.getAbsolutePath() + ".");
iter.remove();
}
}
}
static void linkBlocksHelper(File from, File to, int oldLV, HardLink hl,
boolean upgradeToIdBasedLayout, File blockRoot,
List<LinkArgs> idBasedLayoutSingleLinks) throws IOException {
if (!from.exists()) {
return;
}
if (!from.isDirectory()) {
HardLink.createHardLink(from, to);
hl.linkStats.countSingleLinks++;
return;
}
// from is a directory
hl.linkStats.countDirs++;
String[] blockNames = from.list(new java.io.FilenameFilter() {
@Override
public boolean accept(File dir, String name) {
return name.startsWith(Block.BLOCK_FILE_PREFIX);
}
});
// If we are upgrading to block ID-based layout, we don't want to recreate
// any subdirs from the source that contain blocks, since we have a new
// directory structure
if (!upgradeToIdBasedLayout || !to.getName().startsWith(
BLOCK_SUBDIR_PREFIX)) {
if (!to.mkdirs())
throw new IOException("Cannot create directory " + to);
}
// Block files just need hard links with the same file names
// but a different directory
if (blockNames.length > 0) {
if (upgradeToIdBasedLayout) {
for (String blockName : blockNames) {
long blockId = Block.getBlockId(blockName);
File blockLocation = DatanodeUtil.idToBlockDir(blockRoot, blockId);
if (!blockLocation.exists()) {
if (!blockLocation.mkdirs()) {
throw new IOException("Failed to mkdirs " + blockLocation);
}
}
idBasedLayoutSingleLinks.add(new LinkArgs(new File(from, blockName),
new File(blockLocation, blockName)));
hl.linkStats.countSingleLinks++;
}
} else {
HardLink.createHardLinkMult(from, blockNames, to);
hl.linkStats.countMultLinks++;
hl.linkStats.countFilesMultLinks += blockNames.length;
}
} else {
hl.linkStats.countEmptyDirs++;
}
// Now take care of the rest of the files and subdirectories
String[] otherNames = from.list(new java.io.FilenameFilter() {
@Override
public boolean accept(File dir, String name) {
return name.startsWith(BLOCK_SUBDIR_PREFIX);
}
});
for(int i = 0; i < otherNames.length; i++)
linkBlocksHelper(new File(from, otherNames[i]),
new File(to, otherNames[i]), oldLV, hl, upgradeToIdBasedLayout,
blockRoot, idBasedLayoutSingleLinks);
}
/**
* Add bpStorage into bpStorageMap
*/
private void addBlockPoolStorage(String bpID, BlockPoolSliceStorage bpStorage
) {
if (!this.bpStorageMap.containsKey(bpID)) {
this.bpStorageMap.put(bpID, bpStorage);
}
}
synchronized void removeBlockPoolStorage(String bpId) {
bpStorageMap.remove(bpId);
}
}