/**
* Copyright 2008 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.regionserver;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Random;
import java.util.Set;
import java.util.SortedMap;
import java.util.TreeMap;
import java.util.TreeSet;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import java.util.regex.Pattern;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.ColumnNameParseException;
import org.apache.hadoop.hbase.DroppedSnapshotException;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.HRegionInfo;
import org.apache.hadoop.hbase.HStoreKey;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.NotServingRegionException;
import org.apache.hadoop.hbase.RegionHistorian;
import org.apache.hadoop.hbase.filter.RowFilterInterface;
import org.apache.hadoop.hbase.io.BatchOperation;
import org.apache.hadoop.hbase.io.BatchUpdate;
import org.apache.hadoop.hbase.io.Cell;
import org.apache.hadoop.hbase.io.HbaseMapWritable;
import org.apache.hadoop.hbase.io.Reference;
import org.apache.hadoop.hbase.io.RowResult;
import org.apache.hadoop.hbase.ipc.HRegionInterface;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.FSUtils;
import org.apache.hadoop.hbase.util.Writables;
import org.apache.hadoop.io.WritableUtils;
import org.apache.hadoop.util.Progressable;
import org.apache.hadoop.util.StringUtils;
/**
* HRegion stores data for a certain region of a table. It stores all columns
* for each row. A given table consists of one or more HRegions.
*
* <p>We maintain multiple HStores for a single HRegion.
*
* <p>An HStore is a set of rows with some column data; together,
* they make up all the data for the rows.
*
* <p>Each HRegion has a 'startKey' and 'endKey'.
* <p>The first is inclusive, the second is exclusive (except for
* the final region) The endKey of region 0 is the same as
* startKey for region 1 (if it exists). The startKey for the
* first region is null. The endKey for the final region is null.
*
* <p>Locking at the HRegion level serves only one purpose: preventing the
* region from being closed (and consequently split) while other operations
* are ongoing. Each row level operation obtains both a row lock and a region
* read lock for the duration of the operation. While a scanner is being
* constructed, getScanner holds a read lock. If the scanner is successfully
* constructed, it holds a read lock until it is closed. A close takes out a
* write lock and consequently will block for ongoing operations and will block
* new operations from starting while the close is in progress.
*
* <p>An HRegion is defined by its table and its key extent.
*
* <p>It consists of at least one HStore. The number of HStores should be
* configurable, so that data which is accessed together is stored in the same
* HStore. Right now, we approximate that by building a single HStore for
* each column family. (This config info will be communicated via the
* tabledesc.)
*
* <p>The HTableDescriptor contains metainfo about the HRegion's table.
* regionName is a unique identifier for this HRegion. (startKey, endKey]
* defines the keyspace for this HRegion.
*/
public class HRegion implements HConstants {
static final String SPLITDIR = "splits";
static final String MERGEDIR = "merges";
static final Random rand = new Random();
static final Log LOG = LogFactory.getLog(HRegion.class);
final AtomicBoolean closed = new AtomicBoolean(false);
/* Closing can take some time; use the closing flag if there is stuff we don't want
* to do while in closing state; e.g. like offer this region up to the master as a region
* to close if the carrying regionserver is overloaded. Once set, it is never cleared.
*/
private final AtomicBoolean closing = new AtomicBoolean(false);
private final RegionHistorian historian;
//////////////////////////////////////////////////////////////////////////////
// Members
//////////////////////////////////////////////////////////////////////////////
private final Map<Integer, byte []> locksToRows =
new ConcurrentHashMap<Integer, byte []>();
private final Map<Integer, TreeMap<HStoreKey, byte []>> targetColumns =
new ConcurrentHashMap<Integer, TreeMap<HStoreKey, byte []>>();
// Default access because read by tests.
protected final Map<Integer, HStore> stores =
new ConcurrentHashMap<Integer, HStore>();
final AtomicLong memcacheSize = new AtomicLong(0);
final Path basedir;
final HLog log;
final FileSystem fs;
final HBaseConfiguration conf;
final HRegionInfo regionInfo;
final Path regiondir;
private final Path regionCompactionDir;
/*
* Set this when scheduling compaction if want the next compaction to be a
* major compaction. Cleared each time through compaction code.
*/
private volatile boolean forceMajorCompaction = false;
/*
* Data structure of write state flags used coordinating flushes,
* compactions and closes.
*/
static class WriteState {
// Set while a memcache flush is happening.
volatile boolean flushing = false;
// Set when a flush has been requested.
volatile boolean flushRequested = false;
// Set while a compaction is running.
volatile boolean compacting = false;
// Gets set in close. If set, cannot compact or flush again.
volatile boolean writesEnabled = true;
// Set if region is read-only
private volatile boolean readOnly = false;
/**
* Set flags that make this region read-only.
*/
synchronized void setReadOnly(final boolean onOff) {
this.writesEnabled = !onOff;
this.readOnly = onOff;
}
boolean isReadOnly() {
return this.readOnly;
}
boolean isFlushRequested() {
return this.flushRequested;
}
}
private volatile WriteState writestate = new WriteState();
final int memcacheFlushSize;
private volatile long lastFlushTime;
final FlushRequester flushListener;
private final int blockingMemcacheSize;
final long threadWakeFrequency;
// Used to guard splits and closes
private final ReentrantReadWriteLock splitsAndClosesLock =
new ReentrantReadWriteLock();
private final ReentrantReadWriteLock newScannerLock =
new ReentrantReadWriteLock();
// Stop updates lock
private final ReentrantReadWriteLock updatesLock =
new ReentrantReadWriteLock();
private final Integer splitLock = new Integer(0);
private long minSequenceId;
final AtomicInteger activeScannerCount = new AtomicInteger(0);
//////////////////////////////////////////////////////////////////////////////
// Constructor
//////////////////////////////////////////////////////////////////////////////
/**
* HRegion constructor.
*
* @param basedir qualified path of directory where region should be located,
* usually the table directory.
* @param log The HLog is the outbound log for any updates to the HRegion
* (There's a single HLog for all the HRegions on a single HRegionServer.)
* The log file is a logfile from the previous execution that's
* custom-computed for this HRegion. The HRegionServer computes and sorts the
* appropriate log info for this HRegion. If there is a previous log file
* (implying that the HRegion has been written-to before), then read it from
* the supplied path.
* @param fs is the filesystem.
* @param conf is global configuration settings.
* @param regionInfo - HRegionInfo that describes the region
* is new), then read them from the supplied path.
* @param flushListener an object that implements CacheFlushListener or null
* making progress to master -- otherwise master might think region deploy
* failed. Can be null.
*/
public HRegion(Path basedir, HLog log, FileSystem fs, HBaseConfiguration conf,
HRegionInfo regionInfo, FlushRequester flushListener) {
this.basedir = basedir;
this.log = log;
this.fs = fs;
this.conf = conf;
this.regionInfo = regionInfo;
this.flushListener = flushListener;
this.threadWakeFrequency = conf.getLong(THREAD_WAKE_FREQUENCY, 10 * 1000);
String encodedNameStr = Integer.toString(this.regionInfo.getEncodedName());
this.regiondir = new Path(basedir, encodedNameStr);
this.historian = RegionHistorian.getInstance();
if (LOG.isDebugEnabled()) {
LOG.debug("Opening region " + this + "/" +
this.regionInfo.getEncodedName());
}
this.regionCompactionDir =
new Path(getCompactionDir(basedir), encodedNameStr);
int flushSize = regionInfo.getTableDesc().getMemcacheFlushSize();
if (flushSize == HTableDescriptor.DEFAULT_MEMCACHE_FLUSH_SIZE) {
flushSize = conf.getInt("hbase.hregion.memcache.flush.size",
HTableDescriptor.DEFAULT_MEMCACHE_FLUSH_SIZE);
}
this.memcacheFlushSize = flushSize;
this.blockingMemcacheSize = this.memcacheFlushSize *
conf.getInt("hbase.hregion.memcache.block.multiplier", 1);
}
/** Initialize this region and get it ready to roll.
*
* @param initialFiles
* @param reporter
* @throws IOException
*/
public void initialize( Path initialFiles,
final Progressable reporter) throws IOException {
Path oldLogFile = new Path(regiondir, HREGION_OLDLOGFILE_NAME);
// Move prefab HStore files into place (if any). This picks up split files
// and any merges from splits and merges dirs.
if (initialFiles != null && fs.exists(initialFiles)) {
fs.rename(initialFiles, this.regiondir);
}
// Load in all the HStores.
long maxSeqId = -1;
long minSeqId = Integer.MAX_VALUE;
for (HColumnDescriptor c : this.regionInfo.getTableDesc().getFamilies()) {
HStore store = instantiateHStore(this.basedir, c, oldLogFile, reporter);
stores.put(Bytes.mapKey(c.getName()), store);
long storeSeqId = store.getMaxSequenceId();
if (storeSeqId > maxSeqId) {
maxSeqId = storeSeqId;
}
if (storeSeqId < minSeqId) {
minSeqId = storeSeqId;
}
}
doReconstructionLog(oldLogFile, minSeqId, maxSeqId, reporter);
if (fs.exists(oldLogFile)) {
if (LOG.isDebugEnabled()) {
LOG.debug("Deleting old log file: " + oldLogFile);
}
fs.delete(oldLogFile, false);
}
// Add one to the current maximum sequence id so new edits are beyond.
this.minSequenceId = maxSeqId + 1;
if (LOG.isDebugEnabled()) {
LOG.debug("Next sequence id for region " +
Bytes.toString(regionInfo.getRegionName()) + " is " +
this.minSequenceId);
}
// Get rid of any splits or merges that were lost in-progress
Path splits = new Path(regiondir, SPLITDIR);
if (fs.exists(splits)) {
fs.delete(splits, true);
}
Path merges = new Path(regiondir, MERGEDIR);
if (fs.exists(merges)) {
fs.delete(merges, true);
}
// See if region is meant to run read-only.
if (this.regionInfo.getTableDesc().isReadOnly()) {
this.writestate.setReadOnly(true);
}
// HRegion is ready to go!
this.writestate.compacting = false;
this.lastFlushTime = System.currentTimeMillis();
LOG.info("region " + this + "/" + this.regionInfo.getEncodedName() +
" available");
}
/**
* @return Updates to this region need to have a sequence id that is >= to
* the this number.
*/
long getMinSequenceId() {
return this.minSequenceId;
}
/** @return a HRegionInfo object for this region */
public HRegionInfo getRegionInfo() {
return this.regionInfo;
}
/** @return true if region is closed */
public boolean isClosed() {
return this.closed.get();
}
/**
* @return True if closing process has started.
*/
public boolean isClosing() {
return this.closing.get();
}
/**
* Close down this HRegion. Flush the cache, shut down each HStore, don't
* service any more calls.
*
* <p>This method could take some time to execute, so don't call it from a
* time-sensitive thread.
*
* @return Vector of all the storage files that the HRegion's component
* HStores make use of. It's a list of all HStoreFile objects. Returns empty
* vector if already closed and null if judged that it should not close.
*
* @throws IOException
*/
public List<HStoreFile> close() throws IOException {
return close(false);
}
/**
* Close down this HRegion. Flush the cache unless abort parameter is true,
* Shut down each HStore, don't service any more calls.
*
* This method could take some time to execute, so don't call it from a
* time-sensitive thread.
*
* @param abort true if server is aborting (only during testing)
* @return Vector of all the storage files that the HRegion's component
* HStores make use of. It's a list of HStoreFile objects. Can be null if
* we are not to close at this time or we are already closed.
*
* @throws IOException
*/
List<HStoreFile> close(boolean abort) throws IOException {
if (isClosed()) {
LOG.warn("region " + this + " already closed");
return null;
}
this.closing.set(true);
synchronized (splitLock) {
synchronized (writestate) {
// Disable compacting and flushing by background threads for this
// region.
writestate.writesEnabled = false;
LOG.debug("Closing " + this + ": compactions & flushes disabled ");
while (writestate.compacting || writestate.flushing) {
LOG.debug("waiting for" +
(writestate.compacting ? " compaction" : "") +
(writestate.flushing ?
(writestate.compacting ? "," : "") + " cache flush" :
"") + " to complete for region " + this);
try {
writestate.wait();
} catch (InterruptedException iex) {
// continue
}
}
}
newScannerLock.writeLock().lock();
try {
// Wait for active scanners to finish. The write lock we hold will
// prevent new scanners from being created.
synchronized (activeScannerCount) {
while (activeScannerCount.get() != 0) {
LOG.debug("waiting for " + activeScannerCount.get() +
" scanners to finish");
try {
activeScannerCount.wait();
} catch (InterruptedException e) {
// continue
}
}
}
splitsAndClosesLock.writeLock().lock();
LOG.debug("Updates disabled for region, no outstanding scanners on " +
this);
try {
// Write lock means no more row locks can be given out. Wait on
// outstanding row locks to come in before we close so we do not drop
// outstanding updates.
waitOnRowLocks();
LOG.debug("No more row locks outstanding on region " + this);
// Don't flush the cache if we are aborting
if (!abort) {
internalFlushcache();
}
List<HStoreFile> result = new ArrayList<HStoreFile>();
for (HStore store: stores.values()) {
result.addAll(store.close());
}
this.closed.set(true);
LOG.info("Closed " + this);
return result;
} finally {
splitsAndClosesLock.writeLock().unlock();
}
} finally {
newScannerLock.writeLock().unlock();
}
}
}
//////////////////////////////////////////////////////////////////////////////
// HRegion accessors
//////////////////////////////////////////////////////////////////////////////
/** @return start key for region */
public byte [] getStartKey() {
return this.regionInfo.getStartKey();
}
/** @return end key for region */
public byte [] getEndKey() {
return this.regionInfo.getEndKey();
}
/** @return region id */
public long getRegionId() {
return this.regionInfo.getRegionId();
}
/** @return region name */
public byte [] getRegionName() {
return this.regionInfo.getRegionName();
}
/** @return HTableDescriptor for this region */
public HTableDescriptor getTableDesc() {
return this.regionInfo.getTableDesc();
}
/** @return HLog in use for this region */
public HLog getLog() {
return this.log;
}
/** @return Configuration object */
public HBaseConfiguration getConf() {
return this.conf;
}
/** @return region directory Path */
public Path getRegionDir() {
return this.regiondir;
}
/** @return FileSystem being used by this region */
public FileSystem getFilesystem() {
return this.fs;
}
/** @return the last time the region was flushed */
public long getLastFlushTime() {
return this.lastFlushTime;
}
//////////////////////////////////////////////////////////////////////////////
// HRegion maintenance.
//
// These methods are meant to be called periodically by the HRegionServer for
// upkeep.
//////////////////////////////////////////////////////////////////////////////
/** @return returns size of largest HStore. */
public long getLargestHStoreSize() {
long size = 0;
for (HStore h: stores.values()) {
long storeSize = h.getSize();
if (storeSize > size) {
size = storeSize;
}
}
return size;
}
/*
* Split the HRegion to create two brand-new ones. This also closes
* current HRegion. Split should be fast since we don't rewrite store files
* but instead create new 'reference' store files that read off the top and
* bottom ranges of parent store files.
* @param midKey key on which to split region
* @return two brand-new (and open) HRegions or null if a split is not needed
* @throws IOException
*/
HRegion[] splitRegion(final byte [] midKey) throws IOException {
synchronized (splitLock) {
if (closed.get()) {
return null;
}
// Add start/end key checking: hbase-428.
byte [] startKey = this.regionInfo.getStartKey();
byte [] endKey = this.regionInfo.getEndKey();
if (HStoreKey.equalsTwoRowKeys(this.regionInfo,startKey, midKey)) {
LOG.debug("Startkey and midkey are same, not splitting");
return null;
}
if (HStoreKey.equalsTwoRowKeys(this.regionInfo,midKey, endKey)) {
LOG.debug("Endkey and midkey are same, not splitting");
return null;
}
LOG.info("Starting split of region " + this);
Path splits = new Path(this.regiondir, SPLITDIR);
if(!this.fs.exists(splits)) {
this.fs.mkdirs(splits);
}
// Calculate regionid to use. Can't be less than that of parent else
// it'll insert into wrong location over in .META. table: HBASE-710.
long rid = System.currentTimeMillis();
if (rid < this.regionInfo.getRegionId()) {
LOG.warn("Clock skew; parent regions id is " +
this.regionInfo.getRegionId() + " but current time here is " + rid);
rid = this.regionInfo.getRegionId() + 1;
}
HRegionInfo regionAInfo = new HRegionInfo(this.regionInfo.getTableDesc(),
startKey, midKey, false, rid);
Path dirA =
new Path(splits, Integer.toString(regionAInfo.getEncodedName()));
if(fs.exists(dirA)) {
throw new IOException("Cannot split; target file collision at " + dirA);
}
HRegionInfo regionBInfo = new HRegionInfo(this.regionInfo.getTableDesc(),
midKey, endKey, false, rid);
Path dirB =
new Path(splits, Integer.toString(regionBInfo.getEncodedName()));
if(this.fs.exists(dirB)) {
throw new IOException("Cannot split; target file collision at " + dirB);
}
// Now close the HRegion. Close returns all store files or null if not
// supposed to close (? What to do in this case? Implement abort of close?)
// Close also does wait on outstanding rows and calls a flush just-in-case.
List<HStoreFile> hstoreFilesToSplit = close(false);
if (hstoreFilesToSplit == null) {
LOG.warn("Close came back null (Implement abort of close?)");
throw new RuntimeException("close returned empty vector of HStoreFiles");
}
// Split each store file.
for(HStoreFile h: hstoreFilesToSplit) {
// A reference to the bottom half of the hsf store file.
Reference aReference = new Reference(
this.regionInfo.getEncodedName(), h.getFileId(),
new HStoreKey(midKey, this.regionInfo), Reference.Range.bottom);
HStoreFile a = new HStoreFile(this.conf, fs, splits,
regionAInfo, h.getColFamily(), -1, aReference);
// Reference to top half of the hsf store file.
Reference bReference = new Reference(
this.regionInfo.getEncodedName(), h.getFileId(),
new HStoreKey(midKey, this.regionInfo), Reference.Range.top);
HStoreFile b = new HStoreFile(this.conf, fs, splits,
regionBInfo, h.getColFamily(), -1, bReference);
h.splitStoreFile(a, b, this.fs);
}
// Done!
// Opening the region copies the splits files from the splits directory
// under each region.
HRegion regionA =
new HRegion(basedir, log, fs, conf, regionAInfo, null);
regionA.initialize(dirA, null);
regionA.close();
HRegion regionB =
new HRegion(basedir, log, fs, conf, regionBInfo, null);
regionB.initialize(dirB, null);
regionB.close();
// Cleanup
boolean deleted = fs.delete(splits, true); // Get rid of splits directory
if (LOG.isDebugEnabled()) {
LOG.debug("Cleaned up " + FSUtils.getPath(splits) + " " + deleted);
}
HRegion regions[] = new HRegion [] {regionA, regionB};
this.historian.addRegionSplit(this.regionInfo,
regionA.getRegionInfo(), regionB.getRegionInfo());
return regions;
}
}
/*
* @param dir
* @return compaction directory for the passed in <code>dir</code>
*/
static Path getCompactionDir(final Path dir) {
return new Path(dir, "compaction.dir");
}
/*
* Do preparation for pending compaction.
* Clean out any vestiges of previous failed compactions.
* @throws IOException
*/
private void doRegionCompactionPrep() throws IOException {
doRegionCompactionCleanup();
}
/*
* Removes the compaction directory for this Store.
* @throws IOException
*/
private void doRegionCompactionCleanup() throws IOException {
if (this.fs.exists(this.regionCompactionDir)) {
this.fs.delete(this.regionCompactionDir, true);
}
}
void setForceMajorCompaction(final boolean b) {
this.forceMajorCompaction = b;
}
boolean getForceMajorCompaction() {
return this.forceMajorCompaction;
}
/**
* Called by compaction thread and after region is opened to compact the
* HStores if necessary.
*
* <p>This operation could block for a long time, so don't call it from a
* time-sensitive thread.
*
* Note that no locking is necessary at this level because compaction only
* conflicts with a region split, and that cannot happen because the region
* server does them sequentially and not in parallel.
*
* @return mid key if split is needed
* @throws IOException
*/
public byte [] compactStores() throws IOException {
boolean majorCompaction = this.forceMajorCompaction;
this.forceMajorCompaction = false;
return compactStores(majorCompaction);
}
/*
* Called by compaction thread and after region is opened to compact the
* HStores if necessary.
*
* <p>This operation could block for a long time, so don't call it from a
* time-sensitive thread.
*
* Note that no locking is necessary at this level because compaction only
* conflicts with a region split, and that cannot happen because the region
* server does them sequentially and not in parallel.
*
* @param majorCompaction True to force a major compaction regardless of thresholds
* @return mid key if split is needed
* @throws IOException
*/
byte [] compactStores(final boolean majorCompaction)
throws IOException {
splitsAndClosesLock.readLock().lock();
try {
byte [] midKey = null;
if (this.closed.get()) {
return midKey;
}
try {
synchronized (writestate) {
if (!writestate.compacting && writestate.writesEnabled) {
writestate.compacting = true;
} else {
LOG.info("NOT compacting region " + this +
": compacting=" + writestate.compacting + ", writesEnabled=" +
writestate.writesEnabled);
return midKey;
}
}
LOG.info("starting " + (majorCompaction? "major" : "") +
" compaction on region " + this);
long startTime = System.currentTimeMillis();
doRegionCompactionPrep();
long maxSize = -1;
for (HStore store: stores.values()) {
final HStore.StoreSize size = store.compact(majorCompaction);
if (size != null && size.getSize() > maxSize) {
maxSize = size.getSize();
midKey = size.getKey();
}
}
doRegionCompactionCleanup();
String timeTaken = StringUtils.formatTimeDiff(System.currentTimeMillis(),
startTime);
LOG.info("compaction completed on region " + this + " in " + timeTaken);
this.historian.addRegionCompaction(regionInfo, timeTaken);
} finally {
synchronized (writestate) {
writestate.compacting = false;
writestate.notifyAll();
}
}
return midKey;
} finally {
splitsAndClosesLock.readLock().unlock();
}
}
/**
* Flush the cache.
*
* When this method is called the cache will be flushed unless:
* <ol>
* <li>the cache is empty</li>
* <li>the region is closed.</li>
* <li>a flush is already in progress</li>
* <li>writes are disabled</li>
* </ol>
*
* <p>This method may block for some time, so it should not be called from a
* time-sensitive thread.
*
* @return true if cache was flushed
*
* @throws IOException
* @throws DroppedSnapshotException Thrown when replay of hlog is required
* because a Snapshot was not properly persisted.
*/
public boolean flushcache() throws IOException {
if (this.closed.get()) {
return false;
}
synchronized (writestate) {
if (!writestate.flushing && writestate.writesEnabled) {
this.writestate.flushing = true;
} else {
if(LOG.isDebugEnabled()) {
LOG.debug("NOT flushing memcache for region " + this +
", flushing=" +
writestate.flushing + ", writesEnabled=" +
writestate.writesEnabled);
}
return false;
}
}
try {
// Prevent splits and closes
splitsAndClosesLock.readLock().lock();
try {
return internalFlushcache();
} finally {
splitsAndClosesLock.readLock().unlock();
}
} finally {
synchronized (writestate) {
writestate.flushing = false;
this.writestate.flushRequested = false;
writestate.notifyAll();
}
}
}
/**
* Flushing the cache is a little tricky. We have a lot of updates in the
* HMemcache, all of which have also been written to the log. We need to
* write those updates in the HMemcache out to disk, while being able to
* process reads/writes as much as possible during the flush operation. Also,
* the log has to state clearly the point in time at which the HMemcache was
* flushed. (That way, during recovery, we know when we can rely on the
* on-disk flushed structures and when we have to recover the HMemcache from
* the log.)
*
* <p>So, we have a three-step process:
*
* <ul><li>A. Flush the memcache to the on-disk stores, noting the current
* sequence ID for the log.<li>
*
* <li>B. Write a FLUSHCACHE-COMPLETE message to the log, using the sequence
* ID that was current at the time of memcache-flush.</li>
*
* <li>C. Get rid of the memcache structures that are now redundant, as
* they've been flushed to the on-disk HStores.</li>
* </ul>
* <p>This method is protected, but can be accessed via several public
* routes.
*
* <p> This method may block for some time.
*
* @return true if the region needs compacting
*
* @throws IOException
* @throws DroppedSnapshotException Thrown when replay of hlog is required
* because a Snapshot was not properly persisted.
*/
private boolean internalFlushcache() throws IOException {
final long startTime = System.currentTimeMillis();
// Clear flush flag.
// Record latest flush time
this.lastFlushTime = startTime;
// If nothing to flush, return and avoid logging start/stop flush.
if (this.memcacheSize.get() <= 0) {
return false;
}
if (LOG.isDebugEnabled()) {
LOG.debug("Started memcache flush for region " + this +
". Current region memcache size " +
StringUtils.humanReadableInt(this.memcacheSize.get()));
}
// Stop updates while we snapshot the memcache of all stores. We only have
// to do this for a moment. Its quick. The subsequent sequence id that
// goes into the HLog after we've flushed all these snapshots also goes
// into the info file that sits beside the flushed files.
// We also set the memcache size to zero here before we allow updates
// again so its value will represent the size of the updates received
// during the flush
long sequenceId = -1L;
long completeSequenceId = -1L;
this.updatesLock.writeLock().lock();
// Get current size of memcaches.
final long currentMemcacheSize = this.memcacheSize.get();
try {
for (HStore s: stores.values()) {
s.snapshot();
}
sequenceId = log.startCacheFlush();
completeSequenceId = this.getCompleteCacheFlushSequenceId(sequenceId);
} finally {
this.updatesLock.writeLock().unlock();
}
// Any failure from here on out will be catastrophic requiring server
// restart so hlog content can be replayed and put back into the memcache.
// Otherwise, the snapshot content while backed up in the hlog, it will not
// be part of the current running servers state.
boolean compactionRequested = false;
try {
// A. Flush memcache to all the HStores.
// Keep running vector of all store files that includes both old and the
// just-made new flush store file.
for (HStore hstore: stores.values()) {
boolean needsCompaction = hstore.flushCache(completeSequenceId);
if (needsCompaction) {
compactionRequested = true;
}
}
// Set down the memcache size by amount of flush.
this.memcacheSize.addAndGet(-currentMemcacheSize);
} catch (Throwable t) {
// An exception here means that the snapshot was not persisted.
// The hlog needs to be replayed so its content is restored to memcache.
// Currently, only a server restart will do this.
// We used to only catch IOEs but its possible that we'd get other
// exceptions -- e.g. HBASE-659 was about an NPE -- so now we catch
// all and sundry.
this.log.abortCacheFlush();
DroppedSnapshotException dse = new DroppedSnapshotException("region: " +
Bytes.toString(getRegionName()));
dse.initCause(t);
throw dse;
}
// If we get to here, the HStores have been written. If we get an
// error in completeCacheFlush it will release the lock it is holding
// B. Write a FLUSHCACHE-COMPLETE message to the log.
// This tells future readers that the HStores were emitted correctly,
// and that all updates to the log for this regionName that have lower
// log-sequence-ids can be safely ignored.
this.log.completeCacheFlush(getRegionName(),
regionInfo.getTableDesc().getName(), completeSequenceId);
// C. Finally notify anyone waiting on memcache to clear:
// e.g. checkResources().
synchronized (this) {
notifyAll();
}
if (LOG.isDebugEnabled()) {
long now = System.currentTimeMillis();
String timeTaken = StringUtils.formatTimeDiff(now, startTime);
LOG.debug("Finished memcache flush of ~" +
StringUtils.humanReadableInt(currentMemcacheSize) + " for region " +
this + " in " + (now - startTime) + "ms, sequence id=" + sequenceId +
", compaction requested=" + compactionRequested);
if (!regionInfo.isMetaRegion()) {
this.historian.addRegionFlush(regionInfo, timeTaken);
}
}
return compactionRequested;
}
/**
* Get the sequence number to be associated with this cache flush. Used by
* TransactionalRegion to not complete pending transactions.
*
*
* @param currentSequenceId
* @return sequence id to complete the cache flush with
*/
protected long getCompleteCacheFlushSequenceId(long currentSequenceId) {
return currentSequenceId;
}
//////////////////////////////////////////////////////////////////////////////
// get() methods for client use.
//////////////////////////////////////////////////////////////////////////////
/**
* Fetch multiple versions of a single data item, with timestamp.
*
* @param row
* @param column
* @param ts
* @param nv
* @return array of values one element per version that matches the timestamp,
* or null if there are no matches.
* @throws IOException
*/
public Cell[] get(final byte[] row, final byte[] column, final long ts,
final int nv)
throws IOException {
long timestamp = ts == -1 ? HConstants.LATEST_TIMESTAMP : ts;
int numVersions = nv == -1 ? 1 : nv;
splitsAndClosesLock.readLock().lock();
try {
if (this.closed.get()) {
throw new IOException("Region " + this + " closed");
}
// Make sure this is a valid row and valid column
checkRow(row);
checkColumn(column);
// Don't need a row lock for a simple get
HStoreKey key = new HStoreKey(row, column, timestamp, this.regionInfo);
Cell[] result = getStore(column).get(key, numVersions);
// Guarantee that we return null instead of a zero-length array,
// if there are no results to return.
return (result == null || result.length == 0)? null : result;
} finally {
splitsAndClosesLock.readLock().unlock();
}
}
/**
* Fetch all the columns for the indicated row at a specified timestamp.
* Returns a HbaseMapWritable that maps column names to values.
*
* We should eventually use Bloom filters here, to reduce running time. If
* the database has many column families and is very sparse, then we could be
* checking many files needlessly. A small Bloom for each row would help us
* determine which column groups are useful for that row. That would let us
* avoid a bunch of disk activity.
*
* @param row
* @param columns Array of columns you'd like to retrieve. When null, get all.
* @param ts
* @param numVersions number of versions to retrieve
* @param lockid
* @return HbaseMapWritable<columnName, Cell> values
* @throws IOException
*/
public HbaseMapWritable<byte [], Cell> getFull(final byte [] row,
final Set<byte []> columns, final long ts,
final int numVersions, final Integer lockid)
throws IOException {
// Check columns passed
if (columns != null) {
for (byte [] column: columns) {
checkColumn(column);
}
}
HStoreKey key = new HStoreKey(row, ts, this.regionInfo);
Integer lid = getLock(lockid,row);
HashSet<HStore> storeSet = new HashSet<HStore>();
try {
HbaseMapWritable<byte [], Cell> result =
new HbaseMapWritable<byte [], Cell>();
// Get the concerned columns or all of them
if (columns != null) {
for (byte[] bs : columns) {
HStore store = stores.get(Bytes.mapKey(HStoreKey.getFamily(bs)));
if (store != null) {
storeSet.add(store);
}
}
} else {
storeSet.addAll(stores.values());
}
// For each column name that is just a column family, open the store
// related to it and fetch everything for that row. HBASE-631
// Also remove each store from storeSet so that these stores
// won't be opened for no reason. HBASE-783
if (columns != null) {
for (byte[] bs : columns) {
if (HStoreKey.getFamilyDelimiterIndex(bs) == (bs.length - 1)) {
HStore store = stores.get(Bytes.mapKey(HStoreKey.getFamily(bs)));
store.getFull(key, null, numVersions, result);
storeSet.remove(store);
}
}
}
for (HStore targetStore: storeSet) {
targetStore.getFull(key, columns, numVersions, result);
}
return result;
} finally {
if(lockid == null) releaseRowLock(lid);
}
}
/**
* Return all the data for the row that matches <i>row</i> exactly,
* or the one that immediately preceeds it, at or immediately before
* <i>ts</i>.
*
* @param row row key
* @return map of values
* @throws IOException
*/
RowResult getClosestRowBefore(final byte [] row)
throws IOException{
return getClosestRowBefore(row, HConstants.COLUMN_FAMILY);
}
/**
* Return all the data for the row that matches <i>row</i> exactly,
* or the one that immediately preceeds it, at or immediately before
* <i>ts</i>.
*
* @param row row key
* @param columnFamily Must include the column family delimiter character.
* @return map of values
* @throws IOException
*/
public RowResult getClosestRowBefore(final byte [] row,
final byte [] columnFamily)
throws IOException{
// look across all the HStores for this region and determine what the
// closest key is across all column families, since the data may be sparse
HStoreKey key = null;
checkRow(row);
splitsAndClosesLock.readLock().lock();
try {
HStore store = getStore(columnFamily);
// get the closest key. (HStore.getRowKeyAtOrBefore can return null)
byte [] closestKey = store.getRowKeyAtOrBefore(row);
// If it happens to be an exact match, we can stop.
// Otherwise, we need to check if it's the max and move to the next
if (closestKey != null) {
if (HStoreKey.equalsTwoRowKeys(regionInfo, row, closestKey)) {
key = new HStoreKey(closestKey, this.regionInfo);
}
if (key == null) {
key = new HStoreKey(closestKey, this.regionInfo);
}
}
if (key == null) {
return null;
}
// Now that we've found our key, get the values
HbaseMapWritable<byte [], Cell> cells =
new HbaseMapWritable<byte [], Cell>();
// This will get all results for this store.
store.getFull(key, null, 1, cells);
return new RowResult(key.getRow(), cells);
} finally {
splitsAndClosesLock.readLock().unlock();
}
}
/*
* Get <code>versions</code> keys matching the origin key's
* row/column/timestamp and those of an older vintage.
* Public so available when debugging.
* @param origin Where to start searching.
* @param versions How many versions to return. Pass HConstants.ALL_VERSIONS
* to retrieve all.
* @return Ordered list of <code>versions</code> keys going from newest back.
* @throws IOException
*/
private Set<HStoreKey> getKeys(final HStoreKey origin, final int versions)
throws IOException {
Set<HStoreKey> keys = new TreeSet<HStoreKey>();
Collection<HStore> storesToCheck = null;
if (origin.getColumn() == null || origin.getColumn().length == 0) {
// All families
storesToCheck = this.stores.values();
} else {
storesToCheck = new ArrayList<HStore>(1);
storesToCheck.add(getStore(origin.getColumn()));
}
long now = System.currentTimeMillis();
for (HStore targetStore: storesToCheck) {
if (targetStore != null) {
// Pass versions without modification since in the store getKeys, it
// includes the size of the passed <code>keys</code> array when counting.
List<HStoreKey> r = targetStore.getKeys(origin, versions, now, null);
if (r != null) {
keys.addAll(r);
}
}
}
return keys;
}
/**
* Return an iterator that scans over the HRegion, returning the indicated
* columns for only the rows that match the data filter. This Iterator must
* be closed by the caller.
*
* @param cols columns to scan. If column name is a column family, all
* columns of the specified column family are returned. Its also possible
* to pass a regex in the column qualifier. A column qualifier is judged to
* be a regex if it contains at least one of the following characters:
* <code>\+|^&*$[]]}{)(</code>.
* @param firstRow row which is the starting point of the scan
* @param timestamp only return rows whose timestamp is <= this value
* @param filter row filter
* @return InternalScanner
* @throws IOException
*/
public InternalScanner getScanner(byte[][] cols, byte [] firstRow,
long timestamp, RowFilterInterface filter)
throws IOException {
newScannerLock.readLock().lock();
try {
if (this.closed.get()) {
throw new IOException("Region " + this + " closed");
}
HashSet<HStore> storeSet = new HashSet<HStore>();
for (int i = 0; i < cols.length; i++) {
HStore s = stores.get(Bytes.mapKey(HStoreKey.getFamily(cols[i])));
if (s != null) {
storeSet.add(s);
}
}
return new HScanner(cols, firstRow, timestamp,
storeSet.toArray(new HStore [storeSet.size()]), filter);
} finally {
newScannerLock.readLock().unlock();
}
}
//////////////////////////////////////////////////////////////////////////////
// set() methods for client use.
//////////////////////////////////////////////////////////////////////////////
/**
* @param b
* @throws IOException
*/
public void batchUpdate(BatchUpdate b) throws IOException {
this.batchUpdate(b, null, true);
}
/**
* @param b
* @param writeToWAL
* @throws IOException
*/
public void batchUpdate(BatchUpdate b, boolean writeToWAL) throws IOException {
this.batchUpdate(b, null, writeToWAL);
}
/**
* @param b
* @param lockid
* @throws IOException
*/
public void batchUpdate(BatchUpdate b, Integer lockid) throws IOException {
this.batchUpdate(b, lockid, true);
}
/**
* @param b
* @param lockid
* @param writeToWAL if true, then we write this update to the log
* @throws IOException
*/
public void batchUpdate(BatchUpdate b, Integer lockid, boolean writeToWAL)
throws IOException {
checkReadOnly();
// Do a rough check that we have resources to accept a write. The check is
// 'rough' in that between the resource check and the call to obtain a
// read lock, resources may run out. For now, the thought is that this
// will be extremely rare; we'll deal with it when it happens.
checkResources();
splitsAndClosesLock.readLock().lock();
try {
// We obtain a per-row lock, so other clients will block while one client
// performs an update. The read lock is released by the client calling
// #commit or #abort or if the HRegionServer lease on the lock expires.
// See HRegionServer#RegionListener for how the expire on HRegionServer
// invokes a HRegion#abort.
byte [] row = b.getRow();
// If we did not pass an existing row lock, obtain a new one
Integer lid = getLock(lockid,row);
long commitTime = (b.getTimestamp() == LATEST_TIMESTAMP) ?
System.currentTimeMillis() : b.getTimestamp();
try {
List<byte []> deletes = null;
for (BatchOperation op: b) {
HStoreKey key = new HStoreKey(row, op.getColumn(), commitTime,
this.regionInfo);
byte[] val = null;
if (op.isPut()) {
val = op.getValue();
if (HLogEdit.isDeleted(val)) {
throw new IOException("Cannot insert value: " + val);
}
} else {
if (b.getTimestamp() == LATEST_TIMESTAMP) {
// Save off these deletes
if (deletes == null) {
deletes = new ArrayList<byte []>();
}
deletes.add(op.getColumn());
} else {
val = HLogEdit.deleteBytes.get();
}
}
if (val != null) {
localput(lid, key, val);
}
}
TreeMap<HStoreKey, byte[]> edits =
this.targetColumns.remove(lid);
if (edits != null && edits.size() > 0) {
update(edits, writeToWAL);
}
if (deletes != null && deletes.size() > 0) {
// We have some LATEST_TIMESTAMP deletes to run.
for (byte [] column: deletes) {
deleteMultiple(row, column, LATEST_TIMESTAMP, 1);
}
}
} catch (IOException e) {
this.targetColumns.remove(Long.valueOf(lid));
throw e;
} finally {
if(lockid == null) releaseRowLock(lid);
}
} finally {
splitsAndClosesLock.readLock().unlock();
}
}
/**
* Performs an atomic check and save operation. Checks if
* the specified expected values have changed, and if not
* applies the update.
*
* @param b the update to apply
* @param expectedValues the expected values to check
* @param lockid
* @param writeToWAL whether or not to write to the write ahead log
* @return true if update was applied
* @throws IOException
*/
public boolean checkAndSave(BatchUpdate b,
HbaseMapWritable<byte[], byte[]> expectedValues, Integer lockid,
boolean writeToWAL)
throws IOException {
// This is basically a copy of batchUpdate with the atomic check and save
// added in. So you should read this method with batchUpdate. I will
// comment the areas that I have changed where I have not changed, you
// should read the comments from the batchUpdate method
boolean success = true;
checkReadOnly();
checkResources();
splitsAndClosesLock.readLock().lock();
try {
byte[] row = b.getRow();
Integer lid = getLock(lockid,row);
try {
Set<byte[]> keySet = expectedValues.keySet();
Map<byte[],Cell> actualValues = this.getFull(row,keySet,
HConstants.LATEST_TIMESTAMP, 1,lid);
for (byte[] key : keySet) {
// If test fails exit
if(!Bytes.equals(actualValues.get(key).getValue(),
expectedValues.get(key))) {
success = false;
break;
}
}
if (success) {
long commitTime = (b.getTimestamp() == LATEST_TIMESTAMP)?
System.currentTimeMillis(): b.getTimestamp();
List<byte []> deletes = null;
for (BatchOperation op: b) {
HStoreKey key = new HStoreKey(row, op.getColumn(), commitTime,
this.regionInfo);
byte[] val = null;
if (op.isPut()) {
val = op.getValue();
if (HLogEdit.isDeleted(val)) {
throw new IOException("Cannot insert value: " + val);
}
} else {
if (b.getTimestamp() == LATEST_TIMESTAMP) {
// Save off these deletes
if (deletes == null) {
deletes = new ArrayList<byte []>();
}
deletes.add(op.getColumn());
} else {
val = HLogEdit.deleteBytes.get();
}
}
if (val != null) {
localput(lid, key, val);
}
}
TreeMap<HStoreKey, byte[]> edits =
this.targetColumns.remove(lid);
if (edits != null && edits.size() > 0) {
update(edits, writeToWAL);
}
if (deletes != null && deletes.size() > 0) {
// We have some LATEST_TIMESTAMP deletes to run.
for (byte [] column: deletes) {
deleteMultiple(row, column, LATEST_TIMESTAMP, 1);
}
}
}
} catch (IOException e) {
this.targetColumns.remove(Long.valueOf(lid));
throw e;
} finally {
if(lockid == null) releaseRowLock(lid);
}
} finally {
splitsAndClosesLock.readLock().unlock();
}
return success;
}
/*
* Check if resources to support an update.
*
* Here we synchronize on HRegion, a broad scoped lock. Its appropriate
* given we're figuring in here whether this region is able to take on
* writes. This is only method with a synchronize (at time of writing),
* this and the synchronize on 'this' inside in internalFlushCache to send
* the notify.
*/
private void checkResources() {
boolean blocked = false;
while (this.memcacheSize.get() > this.blockingMemcacheSize) {
requestFlush();
if (!blocked) {
LOG.info("Blocking updates for '" + Thread.currentThread().getName() +
"' on region " + Bytes.toString(getRegionName()) +
": Memcache size " +
StringUtils.humanReadableInt(this.memcacheSize.get()) +
" is >= than blocking " +
StringUtils.humanReadableInt(this.blockingMemcacheSize) + " size");
}
blocked = true;
synchronized(this) {
try {
wait(threadWakeFrequency);
} catch (InterruptedException e) {
// continue;
}
}
}
if (blocked) {
LOG.info("Unblocking updates for region " + this + " '"
+ Thread.currentThread().getName() + "'");
}
}
/**
* Delete all cells of the same age as the passed timestamp or older.
* @param row
* @param column
* @param ts Delete all entries that have this timestamp or older
* @param lockid Row lock
* @throws IOException
*/
public void deleteAll(final byte [] row, final byte [] column, final long ts,
final Integer lockid)
throws IOException {
checkColumn(column);
checkReadOnly();
Integer lid = getLock(lockid,row);
try {
// Delete ALL versions rather than MAX_VERSIONS. If we just did
// MAX_VERSIONS, then if 2* MAX_VERSION cells, subsequent gets would
// get old stuff.
deleteMultiple(row, column, ts, ALL_VERSIONS);
} finally {
if(lockid == null) releaseRowLock(lid);
}
}
/**
* Delete all cells of the same age as the passed timestamp or older.
* @param row
* @param ts Delete all entries that have this timestamp or older
* @param lockid Row lock
* @throws IOException
*/
@SuppressWarnings("unchecked")
public void deleteAll(final byte [] row, final long ts, final Integer lockid)
throws IOException {
checkReadOnly();
Integer lid = getLock(lockid, row);
long now = System.currentTimeMillis();
try {
for (HStore store : stores.values()) {
List<HStoreKey> keys =
store.getKeys(new HStoreKey(row, ts, this.regionInfo),
ALL_VERSIONS, now, null);
TreeMap<HStoreKey, byte []> edits = new TreeMap<HStoreKey, byte []>(
new HStoreKey.HStoreKeyWritableComparator(regionInfo));
for (HStoreKey key: keys) {
edits.put(key, HLogEdit.deleteBytes.get());
}
update(edits);
}
} finally {
if(lockid == null) releaseRowLock(lid);
}
}
/**
* Delete all cells for a row with matching columns with timestamps
* less than or equal to <i>timestamp</i>.
*
* @param row The row to operate on
* @param columnRegex The column regex
* @param timestamp Timestamp to match
* @param lockid Row lock
* @throws IOException
*/
@SuppressWarnings("unchecked")
public void deleteAllByRegex(final byte [] row, final String columnRegex,
final long timestamp, final Integer lockid) throws IOException {
checkReadOnly();
Pattern columnPattern = Pattern.compile(columnRegex);
Integer lid = getLock(lockid, row);
long now = System.currentTimeMillis();
try {
for (HStore store : stores.values()) {
List<HStoreKey> keys =
store.getKeys(new HStoreKey(row, timestamp, this.regionInfo),
ALL_VERSIONS, now, columnPattern);
TreeMap<HStoreKey, byte []> edits = new TreeMap<HStoreKey, byte []>(
new HStoreKey.HStoreKeyWritableComparator(regionInfo));
for (HStoreKey key: keys) {
edits.put(key, HLogEdit.deleteBytes.get());
}
update(edits);
}
} finally {
if(lockid == null) releaseRowLock(lid);
}
}
/**
* Delete all cells for a row with matching column family with timestamps
* less than or equal to <i>timestamp</i>.
*
* @param row The row to operate on
* @param family The column family to match
* @param timestamp Timestamp to match
* @param lockid Row lock
* @throws IOException
*/
@SuppressWarnings("unchecked")
public void deleteFamily(byte [] row, byte [] family, long timestamp,
final Integer lockid)
throws IOException{
checkReadOnly();
Integer lid = getLock(lockid, row);
long now = System.currentTimeMillis();
try {
// find the HStore for the column family
HStore store = getStore(family);
// find all the keys that match our criteria
List<HStoreKey> keys = store.getKeys(new HStoreKey(row, timestamp,
this.regionInfo), ALL_VERSIONS, now, null);
// delete all the cells
TreeMap<HStoreKey, byte []> edits = new TreeMap<HStoreKey, byte []>(
new HStoreKey.HStoreKeyWritableComparator(regionInfo));
for (HStoreKey key: keys) {
edits.put(key, HLogEdit.deleteBytes.get());
}
update(edits);
} finally {
if(lockid == null) releaseRowLock(lid);
}
}
/**
* Delete all cells for a row with all the matching column families by
* familyRegex with timestamps less than or equal to <i>timestamp</i>.
*
* @param row The row to operate on
* @param familyRegex The column family regex for matching. This regex
* expression just match the family name, it didn't include <code>:<code>
* @param timestamp Timestamp to match
* @param lockid Row lock
* @throws IOException
*/
@SuppressWarnings("unchecked")
public void deleteFamilyByRegex(byte [] row, String familyRegex, long timestamp,
final Integer lockid) throws IOException {
checkReadOnly();
// construct the family regex pattern
Pattern familyPattern = Pattern.compile(familyRegex);
Integer lid = getLock(lockid, row);
long now = System.currentTimeMillis();
try {
for(HStore store : stores.values()) {
String familyName = Bytes.toString(store.getFamily().getName());
// check the family name match the family pattern.
if(!(familyPattern.matcher(familyName).matches()))
continue;
List<HStoreKey> keys = store.getKeys(new HStoreKey(row, timestamp,
this.regionInfo), ALL_VERSIONS, now, null);
TreeMap<HStoreKey, byte []> edits = new TreeMap<HStoreKey, byte []>(
new HStoreKey.HStoreKeyWritableComparator(regionInfo));
for (HStoreKey key: keys) {
edits.put(key, HLogEdit.deleteBytes.get());
}
update(edits);
}
} finally {
if(lockid == null) releaseRowLock(lid);
}
}
/*
* Delete one or many cells.
* Used to support {@link #deleteAll(byte [], byte [], long)} and deletion of
* latest cell.
* @param row
* @param column
* @param ts Timestamp to start search on.
* @param versions How many versions to delete. Pass
* {@link HConstants#ALL_VERSIONS} to delete all.
* @throws IOException
*/
@SuppressWarnings("unchecked")
private void deleteMultiple(final byte [] row, final byte [] column,
final long ts, final int versions)
throws IOException {
checkReadOnly();
HStoreKey origin = new HStoreKey(row, column, ts, this.regionInfo);
Set<HStoreKey> keys = getKeys(origin, versions);
if (keys.size() > 0) {
TreeMap<HStoreKey, byte []> edits = new TreeMap<HStoreKey, byte []>(
new HStoreKey.HStoreKeyWritableComparator(regionInfo));
for (HStoreKey key: keys) {
edits.put(key, HLogEdit.deleteBytes.get());
}
update(edits);
}
}
/**
* Tests for the existence of any cells for a given coordinate.
*
* @param row the row
* @param column the column, or null
* @param timestamp the timestamp, or HConstants.LATEST_VERSION for any
* @param lockid the existing lock, or null
* @return true if cells exist for the row, false otherwise
* @throws IOException
*/
public boolean exists(final byte[] row, final byte[] column,
final long timestamp, final Integer lockid)
throws IOException {
checkRow(row);
Integer lid = getLock(lockid, row);
try {
HStoreKey origin;
if (column != null) {
origin = new HStoreKey(row, column, timestamp);
} else {
origin = new HStoreKey(row, timestamp);
}
return !getKeys(origin, 1).isEmpty();
} finally {
if (lockid == null)
releaseRowLock(lid);
}
}
/**
* @throws IOException Throws exception if region is in read-only mode.
*/
protected void checkReadOnly() throws IOException {
if (this.writestate.isReadOnly()) {
throw new IOException("region is read only");
}
}
/**
* Private implementation.
*
* localput() is used for both puts and deletes. We just place the values
* into a per-row pending area, until a commit() or abort() call is received.
* (Or until the user's write-lock expires.)
*
* @param lockid
* @param key
* @param val Value to enter into cell
* @throws IOException
*/
@SuppressWarnings("unchecked")
private void localput(final Integer lockid, final HStoreKey key,
final byte [] val)
throws IOException {
checkColumn(key.getColumn());
checkReadOnly();
TreeMap<HStoreKey, byte []> targets = this.targetColumns.get(lockid);
if (targets == null) {
targets = new TreeMap<HStoreKey, byte []>(
new HStoreKey.HStoreKeyWritableComparator(regionInfo));
this.targetColumns.put(lockid, targets);
}
targets.put(key, val);
}
/**
* Add updates first to the hlog and then add values to memcache.
* Warning: Assumption is caller has lock on passed in row.
* @param updatesByColumn Cell updates by column
* @throws IOException
*/
private void update(final TreeMap<HStoreKey, byte []> updatesByColumn) throws IOException {
this.update(updatesByColumn, true);
}
/**
* Add updates first to the hlog (if writeToWal) and then add values to memcache.
* Warning: Assumption is caller has lock on passed in row.
* @param writeToWAL if true, then we should write to the log
* @param updatesByColumn Cell updates by column
* @throws IOException
*/
private void update(final TreeMap<HStoreKey, byte []> updatesByColumn,
boolean writeToWAL)
throws IOException {
if (updatesByColumn == null || updatesByColumn.size() <= 0) {
return;
}
checkReadOnly();
boolean flush = false;
this.updatesLock.readLock().lock();
try {
if (writeToWAL) {
this.log.append(regionInfo.getRegionName(),
regionInfo.getTableDesc().getName(), updatesByColumn);
}
long size = 0;
for (Map.Entry<HStoreKey, byte[]> e: updatesByColumn.entrySet()) {
HStoreKey key = e.getKey();
size = this.memcacheSize.addAndGet(
getStore(key.getColumn()).add(key, e.getValue()));
}
flush = isFlushSize(size);
} finally {
this.updatesLock.readLock().unlock();
}
if (flush) {
// Request a cache flush. Do it outside update lock.
requestFlush();
}
}
private void requestFlush() {
if (this.flushListener == null) {
return;
}
synchronized (writestate) {
if (this.writestate.isFlushRequested()) {
return;
}
writestate.flushRequested = true;
}
// Make request outside of synchronize block; HBASE-818.
this.flushListener.request(this);
if (LOG.isDebugEnabled()) {
LOG.debug("Flush requested on " + this);
}
}
/*
* @param size
* @return True if size is over the flush threshold
*/
private boolean isFlushSize(final long size) {
return size > this.memcacheFlushSize;
}
// Do any reconstruction needed from the log
@SuppressWarnings("unused")
protected void doReconstructionLog(Path oldLogFile, long minSeqId, long maxSeqId,
Progressable reporter)
throws UnsupportedEncodingException, IOException {
// Nothing to do (Replaying is done in HStores)
}
protected HStore instantiateHStore(Path baseDir,
HColumnDescriptor c, Path oldLogFile, Progressable reporter)
throws IOException {
return new HStore(baseDir, this.regionInfo, c, this.fs, oldLogFile,
this.conf, reporter);
}
/**
* Return HStore instance.
* Use with caution. Exposed for use of fixup utilities.
* @param column Name of column family hosted by this region.
* @return Store that goes with the family on passed <code>column</code>.
* TODO: Make this lookup faster.
*/
public HStore getStore(final byte [] column) {
return this.stores.get(HStoreKey.getFamilyMapKey(column));
}
//////////////////////////////////////////////////////////////////////////////
// Support code
//////////////////////////////////////////////////////////////////////////////
/** Make sure this is a valid row for the HRegion */
private void checkRow(final byte [] row) throws IOException {
if(!rowIsInRange(regionInfo, row)) {
throw new WrongRegionException("Requested row out of range for " +
"HRegion " + this + ", startKey='" +
Bytes.toString(regionInfo.getStartKey()) + "', getEndKey()='" +
Bytes.toString(regionInfo.getEndKey()) + "', row='" +
Bytes.toString(row) + "'");
}
}
/*
* Make sure this is a valid column for the current table
* @param columnName
* @throws NoSuchColumnFamilyException
*/
private void checkColumn(final byte [] columnName)
throws NoSuchColumnFamilyException, ColumnNameParseException {
if (columnName == null) {
return;
}
int index = HStoreKey.getFamilyDelimiterIndex(columnName);
if (index <= 0) {
throw new ColumnNameParseException(Bytes.toString(columnName) +
" is missing column family delimiter '" +
HStoreKey.COLUMN_FAMILY_DELIMITER + "'");
}
if (!regionInfo.getTableDesc().hasFamily(columnName, index)) {
throw new NoSuchColumnFamilyException("Column family on " +
Bytes.toString(columnName) + " does not exist in region " + this
+ " in table " + regionInfo.getTableDesc());
}
}
/**
* Obtain a lock on the given row. Blocks until success.
*
* I know it's strange to have two mappings:
* <pre>
* ROWS ==> LOCKS
* </pre>
* as well as
* <pre>
* LOCKS ==> ROWS
* </pre>
*
* But it acts as a guard on the client; a miswritten client just can't
* submit the name of a row and start writing to it; it must know the correct
* lockid, which matches the lock list in memory.
*
* <p>It would be more memory-efficient to assume a correctly-written client,
* which maybe we'll do in the future.
*
* @param row Name of row to lock.
* @throws IOException
* @return The id of the held lock.
*/
Integer obtainRowLock(final byte [] row) throws IOException {
checkRow(row);
splitsAndClosesLock.readLock().lock();
try {
if (this.closed.get()) {
throw new NotServingRegionException("Region " + this + " closed");
}
Integer key = Bytes.mapKey(row);
synchronized (locksToRows) {
while (locksToRows.containsKey(key)) {
try {
locksToRows.wait();
} catch (InterruptedException ie) {
// Empty
}
}
locksToRows.put(key, row);
locksToRows.notifyAll();
return key;
}
} finally {
splitsAndClosesLock.readLock().unlock();
}
}
/**
* Used by unit tests.
* @param lockid
* @return Row that goes with <code>lockid</code>
*/
byte [] getRowFromLock(final Integer lockid) {
return locksToRows.get(lockid);
}
/**
* Release the row lock!
* @param row Name of row whose lock we are to release
*/
void releaseRowLock(final Integer lockid) {
synchronized (locksToRows) {
locksToRows.remove(lockid);
locksToRows.notifyAll();
}
}
/**
* See if row is currently locked.
* @param lockid
* @return boolean
*/
private boolean isRowLocked(final Integer lockid) {
synchronized (locksToRows) {
if(locksToRows.containsKey(lockid)) {
return true;
}
return false;
}
}
/**
* Returns existing row lock if found, otherwise
* obtains a new row lock and returns it.
* @param lockid
* @return lockid
*/
private Integer getLock(Integer lockid, byte [] row)
throws IOException {
Integer lid = null;
if (lockid == null) {
lid = obtainRowLock(row);
} else {
if(!isRowLocked(lockid)) {
throw new IOException("Invalid row lock");
}
lid = lockid;
}
return lid;
}
private void waitOnRowLocks() {
synchronized (locksToRows) {
while (this.locksToRows.size() > 0) {
LOG.debug("waiting for " + this.locksToRows.size() + " row locks");
try {
this.locksToRows.wait();
} catch (InterruptedException e) {
// Catch. Let while test determine loop-end.
}
}
}
}
@Override
public boolean equals(Object o) {
return this.hashCode() == ((HRegion)o).hashCode();
}
@Override
public int hashCode() {
return this.regionInfo.getRegionName().hashCode();
}
@Override
public String toString() {
return this.regionInfo.getRegionNameAsString();
}
/** @return Path of region base directory */
public Path getBaseDir() {
return this.basedir;
}
/**
* HScanner is an iterator through a bunch of rows in an HRegion.
*/
private class HScanner implements InternalScanner {
private InternalScanner[] scanners;
private TreeMap<byte [], Cell>[] resultSets;
private HStoreKey[] keys;
private RowFilterInterface filter;
/** Create an HScanner with a handle on many HStores. */
@SuppressWarnings("unchecked")
HScanner(byte [][] cols, byte [] firstRow, long timestamp, HStore[] stores,
RowFilterInterface filter)
throws IOException {
this.filter = filter;
this.scanners = new InternalScanner[stores.length];
try {
for (int i = 0; i < stores.length; i++) {
// Only pass relevant columns to each store
List<byte[]> columns = new ArrayList<byte[]>();
for (int j = 0; j < cols.length; j++) {
if (Bytes.equals(HStoreKey.getFamily(cols[j]),
stores[i].getFamily().getName())) {
columns.add(cols[j]);
}
}
RowFilterInterface f = filter;
if (f != null) {
// Need to replicate filters.
// At least WhileMatchRowFilter will mess up the scan if only
// one shared across many rows. See HADOOP-2467.
f = WritableUtils.clone(filter, conf);
}
scanners[i] = stores[i].getScanner(timestamp,
columns.toArray(new byte[columns.size()][]), firstRow, f);
}
} catch (IOException e) {
for (int i = 0; i < this.scanners.length; i++) {
if(scanners[i] != null) {
closeScanner(i);
}
}
throw e;
}
// Advance to the first key in each store.
// All results will match the required column-set and scanTime.
this.resultSets = new TreeMap[scanners.length];
this.keys = new HStoreKey[scanners.length];
for (int i = 0; i < scanners.length; i++) {
keys[i] = new HStoreKey(HConstants.EMPTY_BYTE_ARRAY,regionInfo);
resultSets[i] = new TreeMap<byte [], Cell>(Bytes.BYTES_COMPARATOR);
if(scanners[i] != null && !scanners[i].next(keys[i], resultSets[i])) {
closeScanner(i);
}
}
// As we have now successfully completed initialization, increment the
// activeScanner count.
activeScannerCount.incrementAndGet();
}
@SuppressWarnings("null")
public boolean next(HStoreKey key, SortedMap<byte [], Cell> results)
throws IOException {
boolean moreToFollow = false;
boolean filtered = false;
do {
// Find the lowest-possible key.
byte [] chosenRow = null;
long chosenTimestamp = -1;
for (int i = 0; i < this.keys.length; i++) {
if (scanners[i] != null &&
(chosenRow == null ||
(HStoreKey.compareTwoRowKeys(regionInfo,
keys[i].getRow(), chosenRow) < 0) ||
((HStoreKey.compareTwoRowKeys(regionInfo, keys[i].getRow(),
chosenRow) == 0) &&
(keys[i].getTimestamp() > chosenTimestamp)))) {
chosenRow = keys[i].getRow();
chosenTimestamp = keys[i].getTimestamp();
}
}
// Store the key and results for each sub-scanner. Merge them as
// appropriate.
if (chosenTimestamp >= 0) {
// Here we are setting the passed in key with current row+timestamp
key.setRow(chosenRow);
key.setVersion(chosenTimestamp);
key.setColumn(HConstants.EMPTY_BYTE_ARRAY);
for (int i = 0; i < scanners.length; i++) {
if (scanners[i] != null &&
HStoreKey.compareTwoRowKeys(regionInfo,keys[i].getRow(), chosenRow) == 0) {
// NOTE: We used to do results.putAll(resultSets[i]);
// but this had the effect of overwriting newer
// values with older ones. So now we only insert
// a result if the map does not contain the key.
for (Map.Entry<byte [], Cell> e : resultSets[i].entrySet()) {
if (!results.containsKey(e.getKey())) {
results.put(e.getKey(), e.getValue());
}
}
resultSets[i].clear();
if (!scanners[i].next(keys[i], resultSets[i])) {
closeScanner(i);
}
}
}
}
for (int i = 0; i < scanners.length; i++) {
// If the current scanner is non-null AND has a lower-or-equal
// row label, then its timestamp is bad. We need to advance it.
while ((scanners[i] != null) &&
(HStoreKey.compareTwoRowKeys(regionInfo,keys[i].getRow(), chosenRow) <= 0)) {
resultSets[i].clear();
if (!scanners[i].next(keys[i], resultSets[i])) {
closeScanner(i);
}
}
}
moreToFollow = chosenTimestamp >= 0;
if (results == null || results.size() <= 0) {
// If we got no results, then there is no more to follow.
moreToFollow = false;
}
filtered = filter == null ? false : filter.filterRow(results);
if (filter != null && filter.filterAllRemaining()) {
moreToFollow = false;
}
if (moreToFollow) {
if (filter != null) {
filter.rowProcessed(filtered, key.getRow());
}
if (filtered) {
results.clear();
}
}
} while(filtered && moreToFollow);
// Make sure scanners closed if no more results
if (!moreToFollow) {
for (int i = 0; i < scanners.length; i++) {
if (null != scanners[i]) {
closeScanner(i);
}
}
}
return moreToFollow;
}
/** Shut down a single scanner */
void closeScanner(int i) {
try {
try {
scanners[i].close();
} catch (IOException e) {
LOG.warn("Failed closing scanner " + i, e);
}
} finally {
scanners[i] = null;
// These data members can be null if exception in constructor
if (resultSets != null) {
resultSets[i] = null;
}
if (keys != null) {
keys[i] = null;
}
}
}
public void close() {
try {
for(int i = 0; i < scanners.length; i++) {
if(scanners[i] != null) {
closeScanner(i);
}
}
} finally {
synchronized (activeScannerCount) {
int count = activeScannerCount.decrementAndGet();
if (count < 0) {
LOG.error("active scanner count less than zero: " + count +
" resetting to zero");
activeScannerCount.set(0);
count = 0;
}
if (count == 0) {
activeScannerCount.notifyAll();
}
}
}
}
public boolean isWildcardScanner() {
throw new UnsupportedOperationException("Unimplemented on HScanner");
}
public boolean isMultipleMatchScanner() {
throw new UnsupportedOperationException("Unimplemented on HScanner");
}
}
// Utility methods
/**
* Convenience method creating new HRegions. Used by createTable and by the
* bootstrap code in the HMaster constructor.
* Note, this method creates an {@link HLog} for the created region. It
* needs to be closed explicitly. Use {@link HRegion#getLog()} to get
* access.
* @param info Info for region to create.
* @param rootDir Root directory for HBase instance
* @param conf
* @return new HRegion
*
* @throws IOException
*/
public static HRegion createHRegion(final HRegionInfo info, final Path rootDir,
final HBaseConfiguration conf)
throws IOException {
Path tableDir =
HTableDescriptor.getTableDir(rootDir, info.getTableDesc().getName());
Path regionDir = HRegion.getRegionDir(tableDir, info.getEncodedName());
FileSystem fs = FileSystem.get(conf);
fs.mkdirs(regionDir);
// Note in historian the creation of new region.
if (!info.isMetaRegion()) {
RegionHistorian.getInstance().addRegionCreation(info);
}
HRegion region = new HRegion(tableDir,
new HLog(fs, new Path(regionDir, HREGION_LOGDIR_NAME), conf, null),
fs, conf, info, null);
region.initialize(null, null);
return region;
}
/**
* Convenience method to open a HRegion outside of an HRegionServer context.
* @param info Info for region to be opened.
* @param rootDir Root directory for HBase instance
* @param log HLog for region to use. This method will call
* HLog#setSequenceNumber(long) passing the result of the call to
* HRegion#getMinSequenceId() to ensure the log id is properly kept
* up. HRegionStore does this every time it opens a new region.
* @param conf
* @return new HRegion
*
* @throws IOException
*/
public static HRegion openHRegion(final HRegionInfo info, final Path rootDir,
final HLog log, final HBaseConfiguration conf)
throws IOException {
if (LOG.isDebugEnabled()) {
LOG.debug("Opening region: " + info);
}
if (info == null) {
throw new NullPointerException("Passed region info is null");
}
HRegion r = new HRegion(
HTableDescriptor.getTableDir(rootDir, info.getTableDesc().getName()),
log, FileSystem.get(conf), conf, info, null);
r.initialize(null, null);
if (log != null) {
log.setSequenceNumber(r.getMinSequenceId());
}
return r;
}
/**
* Inserts a new region's meta information into the passed
* <code>meta</code> region. Used by the HMaster bootstrap code adding
* new table to ROOT table.
*
* @param meta META HRegion to be updated
* @param r HRegion to add to <code>meta</code>
*
* @throws IOException
*/
@SuppressWarnings("unchecked")
public static void addRegionToMETA(HRegion meta, HRegion r)
throws IOException {
meta.checkResources();
// The row key is the region name
byte [] row = r.getRegionName();
Integer lid = meta.obtainRowLock(row);
try {
HStoreKey key = new HStoreKey(row, COL_REGIONINFO,
System.currentTimeMillis(), r.getRegionInfo());
TreeMap<HStoreKey, byte[]> edits = new TreeMap<HStoreKey, byte[]>(
new HStoreKey.HStoreKeyWritableComparator(meta.getRegionInfo()));
edits.put(key, Writables.getBytes(r.getRegionInfo()));
meta.update(edits);
} finally {
meta.releaseRowLock(lid);
}
}
/**
* Delete a region's meta information from the passed
* <code>meta</code> region. Removes content in the 'info' column family.
* Does not remove region historian info.
*
* @param srvr META server to be updated
* @param metaRegionName Meta region name
* @param regionName HRegion to remove from <code>meta</code>
*
* @throws IOException
*/
public static void removeRegionFromMETA(final HRegionInterface srvr,
final byte [] metaRegionName, final byte [] regionName)
throws IOException {
srvr.deleteFamily(metaRegionName, regionName, HConstants.COLUMN_FAMILY,
HConstants.LATEST_TIMESTAMP, -1L);
}
/**
* Utility method used by HMaster marking regions offlined.
* @param srvr META server to be updated
* @param metaRegionName Meta region name
* @param info HRegion to update in <code>meta</code>
*
* @throws IOException
*/
public static void offlineRegionInMETA(final HRegionInterface srvr,
final byte [] metaRegionName, final HRegionInfo info)
throws IOException {
BatchUpdate b = new BatchUpdate(info.getRegionName());
info.setOffline(true);
b.put(COL_REGIONINFO, Writables.getBytes(info));
b.delete(COL_SERVER);
b.delete(COL_STARTCODE);
// If carrying splits, they'll be in place when we show up on new
// server.
srvr.batchUpdate(metaRegionName, b, -1L);
}
/**
* Clean COL_SERVER and COL_STARTCODE for passed <code>info</code> in
* <code>.META.</code>
* @param srvr
* @param metaRegionName
* @param info
* @throws IOException
*/
public static void cleanRegionInMETA(final HRegionInterface srvr,
final byte [] metaRegionName, final HRegionInfo info)
throws IOException {
BatchUpdate b = new BatchUpdate(info.getRegionName());
b.delete(COL_SERVER);
b.delete(COL_STARTCODE);
// If carrying splits, they'll be in place when we show up on new
// server.
srvr.batchUpdate(metaRegionName, b, LATEST_TIMESTAMP);
}
/**
* Deletes all the files for a HRegion
*
* @param fs the file system object
* @param rootdir qualified path of HBase root directory
* @param info HRegionInfo for region to be deleted
* @throws IOException
*/
public static void deleteRegion(FileSystem fs, Path rootdir, HRegionInfo info)
throws IOException {
deleteRegion(fs, HRegion.getRegionDir(rootdir, info));
}
private static void deleteRegion(FileSystem fs, Path regiondir)
throws IOException {
if (LOG.isDebugEnabled()) {
LOG.debug("DELETING region " + regiondir.toString());
}
fs.delete(regiondir, true);
}
/**
* Computes the Path of the HRegion
*
* @param tabledir qualified path for table
* @param name ENCODED region name
* @return Path of HRegion directory
*/
public static Path getRegionDir(final Path tabledir, final int name) {
return new Path(tabledir, Integer.toString(name));
}
/**
* Computes the Path of the HRegion
*
* @param rootdir qualified path of HBase root directory
* @param info HRegionInfo for the region
* @return qualified path of region directory
*/
public static Path getRegionDir(final Path rootdir, final HRegionInfo info) {
return new Path(
HTableDescriptor.getTableDir(rootdir, info.getTableDesc().getName()),
Integer.toString(info.getEncodedName()));
}
/**
* Determines if the specified row is within the row range specified by the
* specified HRegionInfo
*
* @param info HRegionInfo that specifies the row range
* @param row row to be checked
* @return true if the row is within the range specified by the HRegionInfo
*/
public static boolean rowIsInRange(HRegionInfo info, final byte [] row) {
return ((info.getStartKey().length == 0) ||
(HStoreKey.compareTwoRowKeys(info,info.getStartKey(), row) <= 0)) &&
((info.getEndKey().length == 0) ||
(HStoreKey.compareTwoRowKeys(info,info.getEndKey(), row) > 0));
}
/**
* Make the directories for a specific column family
*
* @param fs the file system
* @param basedir base directory where region will live (usually the table dir)
* @param encodedRegionName encoded region name
* @param colFamily the column family
* @param tabledesc table descriptor of table
* @throws IOException
*/
public static void makeColumnFamilyDirs(FileSystem fs, Path basedir,
int encodedRegionName, byte [] colFamily, HTableDescriptor tabledesc)
throws IOException {
fs.mkdirs(HStoreFile.getMapDir(basedir, encodedRegionName, colFamily));
fs.mkdirs(HStoreFile.getInfoDir(basedir, encodedRegionName, colFamily));
}
/**
* Merge two HRegions. The regions must be adjacent andmust not overlap.
*
* @param srcA
* @param srcB
* @return new merged HRegion
* @throws IOException
*/
public static HRegion mergeAdjacent(final HRegion srcA, final HRegion srcB)
throws IOException {
HRegion a = srcA;
HRegion b = srcB;
// Make sure that srcA comes first; important for key-ordering during
// write of the merged file.
if (srcA.getStartKey() == null) {
if (srcB.getStartKey() == null) {
throw new IOException("Cannot merge two regions with null start key");
}
// A's start key is null but B's isn't. Assume A comes before B
} else if ((srcB.getStartKey() == null) // A is not null but B is
|| (HStoreKey.compareTwoRowKeys(srcA.getRegionInfo(),
srcA.getStartKey(), srcB.getStartKey()) > 0)) { // A > B
a = srcB;
b = srcA;
}
if (!HStoreKey.equalsTwoRowKeys(srcA.getRegionInfo(),
a.getEndKey(), b.getStartKey())) {
throw new IOException("Cannot merge non-adjacent regions");
}
return merge(a, b);
}
/**
* Merge two regions whether they are adjacent or not.
*
* @param a region a
* @param b region b
* @return new merged region
* @throws IOException
*/
public static HRegion merge(HRegion a, HRegion b) throws IOException {
if (!a.getRegionInfo().getTableDesc().getNameAsString().equals(
b.getRegionInfo().getTableDesc().getNameAsString())) {
throw new IOException("Regions do not belong to the same table");
}
FileSystem fs = a.getFilesystem();
// Make sure each region's cache is empty
a.flushcache();
b.flushcache();
// Compact each region so we only have one store file per family
a.compactStores(true);
if (LOG.isDebugEnabled()) {
LOG.debug("Files for region: " + a);
listPaths(fs, a.getRegionDir());
}
b.compactStores(true);
if (LOG.isDebugEnabled()) {
LOG.debug("Files for region: " + b);
listPaths(fs, b.getRegionDir());
}
HBaseConfiguration conf = a.getConf();
HTableDescriptor tabledesc = a.getTableDesc();
HLog log = a.getLog();
Path basedir = a.getBaseDir();
final byte [] startKey = HStoreKey.equalsTwoRowKeys(a.getRegionInfo(),
a.getStartKey(), EMPTY_BYTE_ARRAY) ||
HStoreKey.equalsTwoRowKeys(a.getRegionInfo(),
b.getStartKey(), EMPTY_BYTE_ARRAY) ? EMPTY_BYTE_ARRAY :
HStoreKey.compareTwoRowKeys(a.getRegionInfo(), a.getStartKey(),
b.getStartKey()) <= 0 ?
a.getStartKey() : b.getStartKey();
final byte [] endKey = HStoreKey.equalsTwoRowKeys(a.getRegionInfo(),
a.getEndKey(), EMPTY_BYTE_ARRAY) ||
HStoreKey.equalsTwoRowKeys(b.getRegionInfo(), b.getEndKey(),
EMPTY_BYTE_ARRAY) ? EMPTY_BYTE_ARRAY :
HStoreKey.compareTwoRowKeys(a.getRegionInfo(), a.getEndKey(),
b.getEndKey()) <= 0 ?
b.getEndKey() : a.getEndKey();
HRegionInfo newRegionInfo = new HRegionInfo(tabledesc, startKey, endKey);
LOG.info("Creating new region " + newRegionInfo.toString());
int encodedName = newRegionInfo.getEncodedName();
Path newRegionDir = HRegion.getRegionDir(a.getBaseDir(), encodedName);
if(fs.exists(newRegionDir)) {
throw new IOException("Cannot merge; target file collision at " +
newRegionDir);
}
fs.mkdirs(newRegionDir);
LOG.info("starting merge of regions: " + a + " and " + b +
" into new region " + newRegionInfo.toString() +
" with start key <" + startKey + "> and end key <" + endKey + ">");
// Move HStoreFiles under new region directory
Map<byte [], List<HStoreFile>> byFamily =
new TreeMap<byte [], List<HStoreFile>>(Bytes.BYTES_COMPARATOR);
byFamily = filesByFamily(byFamily, a.close());
byFamily = filesByFamily(byFamily, b.close());
for (Map.Entry<byte [], List<HStoreFile>> es : byFamily.entrySet()) {
byte [] colFamily = es.getKey();
makeColumnFamilyDirs(fs, basedir, encodedName, colFamily, tabledesc);
// Because we compacted the source regions we should have no more than two
// HStoreFiles per family and there will be no reference store
List<HStoreFile> srcFiles = es.getValue();
if (srcFiles.size() == 2) {
long seqA = srcFiles.get(0).loadInfo(fs);
long seqB = srcFiles.get(1).loadInfo(fs);
if (seqA == seqB) {
// We can't have duplicate sequence numbers
if (LOG.isDebugEnabled()) {
LOG.debug("Adjusting sequence id of storeFile " + srcFiles.get(1) +
" down by one; sequence id A=" + seqA + ", sequence id B=" +
seqB);
}
srcFiles.get(1).writeInfo(fs, seqB - 1);
}
}
for (HStoreFile hsf: srcFiles) {
HStoreFile dst = new HStoreFile(conf, fs, basedir,
newRegionInfo, colFamily, -1, null);
if (LOG.isDebugEnabled()) {
LOG.debug("Renaming " + hsf + " to " + dst);
}
hsf.rename(fs, dst);
}
}
if (LOG.isDebugEnabled()) {
LOG.debug("Files for new region");
listPaths(fs, newRegionDir);
}
HRegion dstRegion = new HRegion(basedir, log, fs, conf, newRegionInfo, null);
dstRegion.initialize(null, null);
dstRegion.compactStores();
if (LOG.isDebugEnabled()) {
LOG.debug("Files for new region");
listPaths(fs, dstRegion.getRegionDir());
}
deleteRegion(fs, a.getRegionDir());
deleteRegion(fs, b.getRegionDir());
LOG.info("merge completed. New region is " + dstRegion);
return dstRegion;
}
/*
* Fills a map with a vector of store files keyed by column family.
* @param byFamily Map to fill.
* @param storeFiles Store files to process.
* @return Returns <code>byFamily</code>
*/
private static Map<byte [], List<HStoreFile>> filesByFamily(
Map<byte [], List<HStoreFile>> byFamily, List<HStoreFile> storeFiles) {
for (HStoreFile src: storeFiles) {
List<HStoreFile> v = byFamily.get(src.getColFamily());
if (v == null) {
v = new ArrayList<HStoreFile>();
byFamily.put(src.getColFamily(), v);
}
v.add(src);
}
return byFamily;
}
/*
* Method to list files in use by region
*/
static void listFiles(FileSystem fs, HRegion r) throws IOException {
listPaths(fs, r.getRegionDir());
}
/**
* @return True if needs a mojor compaction.
* @throws IOException
*/
boolean isMajorCompaction() throws IOException {
for (HStore store: this.stores.values()) {
if (store.isMajorCompaction()) {
return true;
}
}
return false;
}
/*
* List the files under the specified directory
*
* @param fs
* @param dir
* @throws IOException
*/
private static void listPaths(FileSystem fs, Path dir) throws IOException {
if (LOG.isDebugEnabled()) {
FileStatus[] stats = fs.listStatus(dir);
if (stats == null || stats.length == 0) {
return;
}
for (int i = 0; i < stats.length; i++) {
String path = stats[i].getPath().toString();
if (stats[i].isDir()) {
LOG.debug("d " + path);
listPaths(fs, stats[i].getPath());
} else {
LOG.debug("f " + path + " size=" + stats[i].getLen());
}
}
}
}
}