/**
* Copyright 2010 The Apache Software Foundation
*
* 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.hbase.master;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import java.util.UUID;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.HRegionInfo;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.InvalidFamilyOperationException;
import org.apache.hadoop.hbase.RemoteExceptionHandler;
import org.apache.hadoop.hbase.Server;
import org.apache.hadoop.hbase.ServerName;
import org.apache.hadoop.hbase.master.metrics.MasterMetrics;
import org.apache.hadoop.hbase.regionserver.HRegion;
import org.apache.hadoop.hbase.regionserver.wal.HLog;
import org.apache.hadoop.hbase.regionserver.wal.HLogSplitter;
import org.apache.hadoop.hbase.regionserver.wal.OrphanHLogAfterSplitException;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
import org.apache.hadoop.hbase.util.FSTableDescriptors;
import org.apache.hadoop.hbase.util.FSUtils;
/**
* This class abstracts a bunch of operations the HMaster needs to interact with
* the underlying file system, including splitting log files, checking file
* system status, etc.
*/
public class MasterFileSystem {
private static final Log LOG = LogFactory.getLog(MasterFileSystem.class.getName());
// HBase configuration
Configuration conf;
// master status
Server master;
// metrics for master
MasterMetrics metrics;
// Persisted unique cluster ID
private String clusterId;
// Keep around for convenience.
private final FileSystem fs;
// Is the fileystem ok?
private volatile boolean fsOk = true;
// The Path to the old logs dir
private final Path oldLogDir;
// root hbase directory on the FS
private final Path rootdir;
// create the split log lock
final Lock splitLogLock = new ReentrantLock();
final boolean distributedLogSplitting;
final SplitLogManager splitLogManager;
private final MasterServices services;
public MasterFileSystem(Server master, MasterServices services,
MasterMetrics metrics)
throws IOException {
this.conf = master.getConfiguration();
this.master = master;
this.services = services;
this.metrics = metrics;
// Set filesystem to be that of this.rootdir else we get complaints about
// mismatched filesystems if hbase.rootdir is hdfs and fs.defaultFS is
// default localfs. Presumption is that rootdir is fully-qualified before
// we get to here with appropriate fs scheme.
this.rootdir = FSUtils.getRootDir(conf);
// Cover both bases, the old way of setting default fs and the new.
// We're supposed to run on 0.20 and 0.21 anyways.
this.fs = this.rootdir.getFileSystem(conf);
String fsUri = this.fs.getUri().toString();
conf.set("fs.default.name", fsUri);
conf.set("fs.defaultFS", fsUri);
this.distributedLogSplitting =
conf.getBoolean("hbase.master.distributed.log.splitting", true);
if (this.distributedLogSplitting) {
this.splitLogManager = new SplitLogManager(master.getZooKeeper(),
master.getConfiguration(), master, master.getServerName().toString());
this.splitLogManager.finishInitialization();
} else {
this.splitLogManager = null;
}
// setup the filesystem variable
// set up the archived logs path
this.oldLogDir = new Path(this.rootdir, HConstants.HREGION_OLDLOGDIR_NAME);
createInitialFileSystemLayout();
}
/**
* Create initial layout in filesystem.
* <ol>
* <li>Check if the root region exists and is readable, if not create it.
* Create hbase.version and the -ROOT- directory if not one.
* </li>
* <li>Create a log archive directory for RS to put archived logs</li>
* </ol>
* Idempotent.
*/
private void createInitialFileSystemLayout() throws IOException {
// check if the root directory exists
checkRootDir(this.rootdir, conf, this.fs);
// Make sure the region servers can archive their old logs
if(!this.fs.exists(this.oldLogDir)) {
this.fs.mkdirs(this.oldLogDir);
}
}
public FileSystem getFileSystem() {
return this.fs;
}
/**
* Get the directory where old logs go
* @return the dir
*/
public Path getOldLogDir() {
return this.oldLogDir;
}
/**
* Checks to see if the file system is still accessible.
* If not, sets closed
* @return false if file system is not available
*/
public boolean checkFileSystem() {
if (this.fsOk) {
try {
FSUtils.checkFileSystemAvailable(this.fs);
FSUtils.checkDfsSafeMode(this.conf);
} catch (IOException e) {
master.abort("Shutting down HBase cluster: file system not available", e);
this.fsOk = false;
}
}
return this.fsOk;
}
/**
* @return HBase root dir.
*/
public Path getRootDir() {
return this.rootdir;
}
/**
* @return The unique identifier generated for this cluster
*/
public String getClusterId() {
return clusterId;
}
/**
* Inspect the log directory to recover any log file without
* an active region server.
* @param onlineServers Set of online servers keyed by
* {@link ServerName}
*/
void splitLogAfterStartup(final Set<ServerName> onlineServers) {
boolean retrySplitting = !conf.getBoolean("hbase.hlog.split.skip.errors",
HLog.SPLIT_SKIP_ERRORS_DEFAULT);
Path logsDirPath = new Path(this.rootdir, HConstants.HREGION_LOGDIR_NAME);
do {
List<ServerName> serverNames = new ArrayList<ServerName>();
try {
if (!this.fs.exists(logsDirPath)) return;
FileStatus[] logFolders = FSUtils.listStatus(this.fs, logsDirPath, null);
if (logFolders == null || logFolders.length == 0) {
LOG.debug("No log files to split, proceeding...");
return;
}
for (FileStatus status : logFolders) {
String sn = status.getPath().getName();
// truncate splitting suffix if present (for ServerName parsing)
if (sn.endsWith(HLog.SPLITTING_EXT)) {
sn = sn.substring(0, sn.length() - HLog.SPLITTING_EXT.length());
}
ServerName serverName = ServerName.parseServerName(sn);
if (!onlineServers.contains(serverName)) {
LOG.info("Log folder " + status.getPath() + " doesn't belong "
+ "to a known region server, splitting");
serverNames.add(serverName);
} else {
LOG.info("Log folder " + status.getPath()
+ " belongs to an existing region server");
}
}
splitLog(serverNames);
retrySplitting = false;
} catch (IOException ioe) {
LOG.warn("Failed splitting of " + serverNames, ioe);
if (!checkFileSystem()) {
LOG.warn("Bad Filesystem, exiting");
Runtime.getRuntime().halt(1);
}
try {
if (retrySplitting) {
Thread.sleep(conf.getInt(
"hbase.hlog.split.failure.retry.interval", 30 * 1000));
}
} catch (InterruptedException e) {
LOG.warn("Interrupted, aborting since cannot return w/o splitting");
Thread.currentThread().interrupt();
retrySplitting = false;
Runtime.getRuntime().halt(1);
}
}
} while (retrySplitting);
}
public void splitLog(final ServerName serverName) throws IOException {
List<ServerName> serverNames = new ArrayList<ServerName>();
serverNames.add(serverName);
splitLog(serverNames);
}
public void splitLog(final List<ServerName> serverNames) throws IOException {
long splitTime = 0, splitLogSize = 0;
List<Path> logDirs = new ArrayList<Path>();
for(ServerName serverName: serverNames){
Path logDir = new Path(this.rootdir,
HLog.getHLogDirectoryName(serverName.toString()));
Path splitDir = logDir.suffix(HLog.SPLITTING_EXT);
// rename the directory so a rogue RS doesn't create more HLogs
if (fs.exists(logDir)) {
if (!this.fs.rename(logDir, splitDir)) {
throw new IOException("Failed fs.rename for log split: " + logDir);
}
logDir = splitDir;
LOG.debug("Renamed region directory: " + splitDir);
} else if (!fs.exists(splitDir)) {
LOG.info("Log dir for server " + serverName + " does not exist");
continue;
}
logDirs.add(splitDir);
}
if (logDirs.isEmpty()) {
LOG.info("No logs to split");
return;
}
if (distributedLogSplitting) {
for (ServerName serverName : serverNames) {
splitLogManager.handleDeadWorker(serverName.toString());
}
splitTime = EnvironmentEdgeManager.currentTimeMillis();
splitLogSize = splitLogManager.splitLogDistributed(logDirs);
splitTime = EnvironmentEdgeManager.currentTimeMillis() - splitTime;
} else {
for(Path logDir: logDirs){
// splitLogLock ensures that dead region servers' logs are processed
// one at a time
this.splitLogLock.lock();
try {
HLogSplitter splitter = HLogSplitter.createLogSplitter(
conf, rootdir, logDir, oldLogDir, this.fs);
try {
// If FS is in safe mode, just wait till out of it.
FSUtils.waitOnSafeMode(conf, conf.getInt(HConstants.THREAD_WAKE_FREQUENCY, 1000));
splitter.splitLog();
} catch (OrphanHLogAfterSplitException e) {
LOG.warn("Retrying splitting because of:", e);
//An HLogSplitter instance can only be used once. Get new instance.
splitter = HLogSplitter.createLogSplitter(conf, rootdir, logDir,
oldLogDir, this.fs);
splitter.splitLog();
}
splitTime = splitter.getTime();
splitLogSize = splitter.getSize();
} finally {
this.splitLogLock.unlock();
}
}
}
if (this.metrics != null) {
this.metrics.addSplit(splitTime, splitLogSize);
}
}
/**
* Get the rootdir. Make sure its wholesome and exists before returning.
* @param rd
* @param conf
* @param fs
* @return hbase.rootdir (after checks for existence and bootstrapping if
* needed populating the directory with necessary bootup files).
* @throws IOException
*/
private Path checkRootDir(final Path rd, final Configuration c,
final FileSystem fs)
throws IOException {
// If FS is in safe mode wait till out of it.
FSUtils.waitOnSafeMode(c, c.getInt(HConstants.THREAD_WAKE_FREQUENCY,
10 * 1000));
// Filesystem is good. Go ahead and check for hbase.rootdir.
if (!fs.exists(rd)) {
fs.mkdirs(rd);
// DFS leaves safe mode with 0 DNs when there are 0 blocks.
// We used to handle this by checking the current DN count and waiting until
// it is nonzero. With security, the check for datanode count doesn't work --
// it is a privileged op. So instead we adopt the strategy of the jobtracker
// and simply retry file creation during bootstrap indefinitely. As soon as
// there is one datanode it will succeed. Permission problems should have
// already been caught by mkdirs above.
FSUtils.setVersion(fs, rd, c.getInt(HConstants.THREAD_WAKE_FREQUENCY,
10 * 1000));
} else {
// as above
FSUtils.checkVersion(fs, rd, true, c.getInt(HConstants.THREAD_WAKE_FREQUENCY,
10 * 1000));
}
// Make sure cluster ID exists
if (!FSUtils.checkClusterIdExists(fs, rd, c.getInt(
HConstants.THREAD_WAKE_FREQUENCY, 10 * 1000))) {
FSUtils.setClusterId(fs, rd, UUID.randomUUID().toString(), c.getInt(
HConstants.THREAD_WAKE_FREQUENCY, 10 * 1000));
}
clusterId = FSUtils.getClusterId(fs, rd);
// Make sure the root region directory exists!
if (!FSUtils.rootRegionExists(fs, rd)) {
bootstrap(rd, c);
}
createRootTableInfo(rd);
return rd;
}
private void createRootTableInfo(Path rd) throws IOException {
// Create ROOT tableInfo if required.
if (!FSTableDescriptors.isTableInfoExists(fs, rd,
Bytes.toString(HRegionInfo.ROOT_REGIONINFO.getTableName()))) {
FSTableDescriptors.createTableDescriptor(HTableDescriptor.ROOT_TABLEDESC, this.conf);
}
}
private static void bootstrap(final Path rd, final Configuration c)
throws IOException {
LOG.info("BOOTSTRAP: creating ROOT and first META regions");
try {
// Bootstrapping, make sure blockcache is off. Else, one will be
// created here in bootstap and it'll need to be cleaned up. Better to
// not make it in first place. Turn off block caching for bootstrap.
// Enable after.
HRegionInfo rootHRI = new HRegionInfo(HRegionInfo.ROOT_REGIONINFO);
setInfoFamilyCachingForRoot(false);
HRegionInfo metaHRI = new HRegionInfo(HRegionInfo.FIRST_META_REGIONINFO);
setInfoFamilyCachingForMeta(false);
HRegion root = HRegion.createHRegion(rootHRI, rd, c,
HTableDescriptor.ROOT_TABLEDESC);
HRegion meta = HRegion.createHRegion(metaHRI, rd, c,
HTableDescriptor.META_TABLEDESC);
setInfoFamilyCachingForRoot(true);
setInfoFamilyCachingForMeta(true);
// Add first region from the META table to the ROOT region.
HRegion.addRegionToMETA(root, meta);
root.close();
root.getLog().closeAndDelete();
meta.close();
meta.getLog().closeAndDelete();
} catch (IOException e) {
e = RemoteExceptionHandler.checkIOException(e);
LOG.error("bootstrap", e);
throw e;
}
}
/**
* Enable in-memory caching for -ROOT-
*/
public static void setInfoFamilyCachingForRoot(final boolean b) {
for (HColumnDescriptor hcd:
HTableDescriptor.ROOT_TABLEDESC.getColumnFamilies()) {
if (Bytes.equals(hcd.getName(), HConstants.CATALOG_FAMILY)) {
hcd.setBlockCacheEnabled(b);
hcd.setInMemory(b);
}
}
}
/**
* Enable in memory caching for .META.
*/
public static void setInfoFamilyCachingForMeta(final boolean b) {
for (HColumnDescriptor hcd:
HTableDescriptor.META_TABLEDESC.getColumnFamilies()) {
if (Bytes.equals(hcd.getName(), HConstants.CATALOG_FAMILY)) {
hcd.setBlockCacheEnabled(b);
hcd.setInMemory(b);
}
}
}
public void deleteRegion(HRegionInfo region) throws IOException {
fs.delete(HRegion.getRegionDir(rootdir, region), true);
}
public void deleteTable(byte[] tableName) throws IOException {
fs.delete(new Path(rootdir, Bytes.toString(tableName)), true);
}
public void updateRegionInfo(HRegionInfo region) {
// TODO implement this. i think this is currently broken in trunk i don't
// see this getting updated.
// @see HRegion.checkRegioninfoOnFilesystem()
}
public void stop() {
if (splitLogManager != null) {
this.splitLogManager.stop();
}
}
/**
* Create new HTableDescriptor in HDFS.
*
* @param htableDescriptor
*/
public void createTableDescriptor(HTableDescriptor htableDescriptor)
throws IOException {
FSTableDescriptors.createTableDescriptor(htableDescriptor, conf);
}
/**
* Delete column of a table
* @param tableName
* @param familyName
* @return Modified HTableDescriptor with requested column deleted.
* @throws IOException
*/
public HTableDescriptor deleteColumn(byte[] tableName, byte[] familyName)
throws IOException {
LOG.info("DeleteColumn. Table = " + Bytes.toString(tableName)
+ " family = " + Bytes.toString(familyName));
HTableDescriptor htd = this.services.getTableDescriptors().get(tableName);
htd.removeFamily(familyName);
this.services.getTableDescriptors().add(htd);
return htd;
}
/**
* Modify Column of a table
* @param tableName
* @param hcd HColumnDesciptor
* @return Modified HTableDescriptor with the column modified.
* @throws IOException
*/
public HTableDescriptor modifyColumn(byte[] tableName, HColumnDescriptor hcd)
throws IOException {
LOG.info("AddModifyColumn. Table = " + Bytes.toString(tableName)
+ " HCD = " + hcd.toString());
HTableDescriptor htd = this.services.getTableDescriptors().get(tableName);
byte [] familyName = hcd.getName();
if(!htd.hasFamily(familyName)) {
throw new InvalidFamilyOperationException("Family '" +
Bytes.toString(familyName) + "' doesn't exists so cannot be modified");
}
htd.addFamily(hcd);
this.services.getTableDescriptors().add(htd);
return htd;
}
/**
* Add column to a table
* @param tableName
* @param hcd
* @return Modified HTableDescriptor with new column added.
* @throws IOException
*/
public HTableDescriptor addColumn(byte[] tableName, HColumnDescriptor hcd)
throws IOException {
LOG.info("AddColumn. Table = " + Bytes.toString(tableName) + " HCD = " +
hcd.toString());
HTableDescriptor htd = this.services.getTableDescriptors().get(tableName);
if (htd == null) {
throw new InvalidFamilyOperationException("Family '" +
hcd.getNameAsString() + "' cannot be modified as HTD is null");
}
htd.addFamily(hcd);
this.services.getTableDescriptors().add(htd);
return htd;
}
}