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Posted to commits@hbase.apache.org by ns...@apache.org on 2011/01/21 06:17:32 UTC
svn commit: r1061637 - in
/hbase/trunk/src/main/java/org/apache/hadoop/hbase: client/HTable.java
util/RegionSplitter.java
Author: nspiegelberg
Date: Fri Jan 21 05:17:32 2011
New Revision: 1061637
URL: http://svn.apache.org/viewvc?rev=1061637&view=rev
Log:
HBASE-3448 : RegionSplitter, utility class to manually split tables
Added:
hbase/trunk/src/main/java/org/apache/hadoop/hbase/util/RegionSplitter.java
Modified:
hbase/trunk/src/main/java/org/apache/hadoop/hbase/client/HTable.java
Modified: hbase/trunk/src/main/java/org/apache/hadoop/hbase/client/HTable.java
URL: http://svn.apache.org/viewvc/hbase/trunk/src/main/java/org/apache/hadoop/hbase/client/HTable.java?rev=1061637&r1=1061636&r2=1061637&view=diff
==============================================================================
--- hbase/trunk/src/main/java/org/apache/hadoop/hbase/client/HTable.java (original)
+++ hbase/trunk/src/main/java/org/apache/hadoop/hbase/client/HTable.java Fri Jan 21 05:17:32 2011
@@ -19,9 +19,9 @@
*/
package org.apache.hadoop.hbase.client;
-import java.io.IOException;
import java.io.DataInput;
import java.io.DataOutput;
+import java.io.IOException;
import java.lang.reflect.Proxy;
import java.util.ArrayList;
import java.util.Arrays;
@@ -1330,6 +1330,14 @@ public class HTable implements HTableInt
getRegionCachePrefetch(tableName);
}
+ /**
+ * Explicitly clears the region cache to fetch the latest value from META.
+ * This is a power user function: avoid unless you know the ramifications.
+ */
+ public void clearRegionCache() {
+ this.connection.clearRegionCache();
+ }
+
@Override
public <T extends CoprocessorProtocol> T coprocessorProxy(
Class<T> protocol, byte[] row) {
Added: hbase/trunk/src/main/java/org/apache/hadoop/hbase/util/RegionSplitter.java
URL: http://svn.apache.org/viewvc/hbase/trunk/src/main/java/org/apache/hadoop/hbase/util/RegionSplitter.java?rev=1061637&view=auto
==============================================================================
--- hbase/trunk/src/main/java/org/apache/hadoop/hbase/util/RegionSplitter.java (added)
+++ hbase/trunk/src/main/java/org/apache/hadoop/hbase/util/RegionSplitter.java Fri Jan 21 05:17:32 2011
@@ -0,0 +1,744 @@
+/**
+ * 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.util;
+
+import java.io.IOException;
+import java.math.BigInteger;
+import java.util.LinkedList;
+import java.util.Set;
+import java.util.TreeMap;
+
+import org.apache.commons.cli.CommandLine;
+import org.apache.commons.cli.GnuParser;
+import org.apache.commons.cli.HelpFormatter;
+import org.apache.commons.cli.OptionBuilder;
+import org.apache.commons.cli.Options;
+import org.apache.commons.cli.ParseException;
+import org.apache.commons.lang.StringUtils;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FSDataOutputStream;
+import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+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.HRegionLocation;
+import org.apache.hadoop.hbase.HServerAddress;
+import org.apache.hadoop.hbase.HTableDescriptor;
+import org.apache.hadoop.hbase.client.HBaseAdmin;
+import org.apache.hadoop.hbase.client.HTable;
+import org.apache.hadoop.hbase.regionserver.Store;
+import org.apache.hadoop.hbase.regionserver.StoreFile;
+
+import com.google.common.base.Preconditions;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
+import com.google.common.collect.Sets;
+
+/**
+ * The {@link RegionSplitter} class provides several utilities to help in the
+ * administration lifecycle for developers who choose to manually split regions
+ * instead of having HBase handle that automatically. The most useful utilities
+ * are:
+ * <p>
+ * <ul>
+ * <li>Create a table with a specified number of pre-split regions
+ * <li>Execute a rolling split of all regions on an existing table
+ * </ul>
+ * <p>
+ * Both operations can be safely done on a live server.
+ * <p>
+ * <b>Question:</b> How do I turn off automatic splitting? <br>
+ * <b>Answer:</b> Automatic splitting is determined by the configuration value
+ * <i>"hbase.hregion.max.filesize"</i>. It is not recommended that you set this
+ * to Long.MAX_VALUE in case you forget about manual splits. A suggested setting
+ * is 100GB, which would result in > 1hr major compactions if reached.
+ * <p>
+ * <b>Question:</b> Why did the original authors decide to manually split? <br>
+ * <b>Answer:</b> Specific workload characteristics of our use case allowed us
+ * to benefit from a manual split system.
+ * <p>
+ * <ul>
+ * <li>Data (~1k) that would grow instead of being replaced
+ * <li>Data growth was roughly uniform across all regions
+ * <li>OLTP workload. Data loss is a big deal.
+ * </ul>
+ * <p>
+ * <b>Question:</b> Why is manual splitting good for this workload? <br>
+ * <b>Answer:</b> Although automated splitting is not a bad option, there are
+ * benefits to manual splitting.
+ * <p>
+ * <ul>
+ * <li>With growing amounts of data, splits will continually be needed. Since
+ * you always know exactly what regions you have, long-term debugging and
+ * profiling is much easier with manual splits. It is hard to trace the logs to
+ * understand region level problems if it keeps splitting and getting renamed.
+ * <li>Data offlining bugs + unknown number of split regions == oh crap! If an
+ * HLog or StoreFile was mistakenly unprocessed by HBase due to a weird bug and
+ * you notice it a day or so later, you can be assured that the regions
+ * specified in these files are the same as the current regions and you have
+ * less headaches trying to restore/replay your data.
+ * <li>You can finely tune your compaction algorithm. With roughly uniform data
+ * growth, it's easy to cause split / compaction storms as the regions all
+ * roughly hit the same data size at the same time. With manual splits, you can
+ * let staggered, time-based major compactions spread out your network IO load.
+ * </ul>
+ * <p>
+ * <b>Question:</b> What's the optimal number of pre-split regions to create? <br>
+ * <b>Answer:</b> Mileage will vary depending upon your application.
+ * <p>
+ * The short answer for our application is that we started with 10 pre-split
+ * regions / server and watched our data growth over time. It's better to err on
+ * the side of too little regions and rolling split later.
+ * <p>
+ * The more complicated answer is that this depends upon the largest storefile
+ * in your region. With a growing data size, this will get larger over time. You
+ * want the largest region to be just big enough that the {@link Store} compact
+ * selection algorithm only compacts it due to a timed major. If you don't, your
+ * cluster can be prone to compaction storms as the algorithm decides to run
+ * major compactions on a large series of regions all at once. Note that
+ * compaction storms are due to the uniform data growth, not the manual split
+ * decision.
+ * <p>
+ * If you pre-split your regions too thin, you can increase the major compaction
+ * interval by configuring HConstants.MAJOR_COMPACTION_PERIOD. If your data size
+ * grows too large, use this script to perform a network IO safe rolling split
+ * of all regions.
+ */
+public class RegionSplitter {
+ static final Log LOG = LogFactory.getLog(RegionSplitter.class);
+
+ /**
+ * A generic interface for the RegionSplitter code to use for all it's
+ * functionality. Note that the original authors of this code use
+ * {@link MD5StringSplit} to partition their table and set it as default, but
+ * provided this for your custom algorithm. To use, create a new derived class
+ * from this interface and call the RegionSplitter class with the argument: <br>
+ * <b>-D split.algorithm=<your_class_path></b>
+ */
+ public static interface SplitAlgorithm {
+ /**
+ * Split a pre-existing region into 2 regions.
+ *
+ * @param start
+ * row
+ * @param end
+ * row
+ * @return the split row to use
+ */
+ byte[] split(byte[] start, byte[] end);
+
+ /**
+ * Split an entire table.
+ *
+ * @param numberOfSplits
+ * number of regions to split the table into
+ *
+ * @return array of split keys for the initial regions of the table
+ */
+ byte[][] split(int numberOfSplits);
+
+ /**
+ * In HBase, the first row is represented by an empty byte array. This might
+ * cause problems with your split algorithm or row printing. All your APIs
+ * will be passed firstRow() instead of empty array.
+ *
+ * @return your representation of your first row
+ */
+ byte[] firstRow();
+
+ /**
+ * In HBase, the last row is represented by an empty byte array. This might
+ * cause problems with your split algorithm or row printing. All your APIs
+ * will be passed firstRow() instead of empty array.
+ *
+ * @return your representation of your last row
+ */
+ byte[] lastRow();
+
+ /**
+ * @param input
+ * user or file input for row
+ * @return byte array representation of this row for HBase
+ */
+ byte[] strToRow(String input);
+
+ /**
+ * @param row
+ * byte array representing a row in HBase
+ * @return String to use for debug & file printing
+ */
+ String rowToStr(byte[] row);
+
+ /**
+ * @return the separator character to use when storing / printing the row
+ */
+ String separator();
+ }
+
+ /**
+ * The main function for the RegionSplitter application. Common uses:
+ * <p>
+ * <ul>
+ * <li>create a table named 'myTable' with 60 pre-split regions containing 2
+ * column families 'test' & 'rs' bin/hbase
+ * <ul>
+ * <li>org.apache.hadoop.hbase.util.RegionSplitter -c 60 -f test:rs myTable
+ * </ul>
+ * <li>perform a rolling split of 'myTable' (i.e. 60 => 120 regions), # 2
+ * outstanding splits at a time bin/hbase
+ * <ul>
+ * <li>org.apache.hadoop.hbase.util.RegionSplitter -r -o 2 myTable
+ * </ul>
+ * </ul>
+ *
+ * @param args
+ * Usage: RegionSplitter <TABLE> <-c <# regions> -f
+ * <family:family:...> | -r [-o <# outstanding
+ * splits>]> [-D <conf.param=value>]
+ * @throws IOException
+ * HBase IO problem
+ * @throws InterruptedException
+ * user requested exit
+ * @throws ParseException
+ * problem parsing user input
+ */
+ @SuppressWarnings("static-access")
+ public static void main(String[] args) throws IOException,
+ InterruptedException, ParseException {
+ Configuration conf = HBaseConfiguration.create();
+
+ // parse user input
+ Options opt = new Options();
+ opt.addOption(OptionBuilder.withArgName("property=value").hasArg()
+ .withDescription("Override HBase Configuration Settings").create("D"));
+ opt.addOption(OptionBuilder.withArgName("region count").hasArg()
+ .withDescription(
+ "Create a new table with a pre-split number of regions")
+ .create("c"));
+ opt.addOption(OptionBuilder.withArgName("family:family:...").hasArg()
+ .withDescription(
+ "Column Families to create with new table. Required with -c")
+ .create("f"));
+ opt.addOption("h", false, "Print this usage help");
+ opt.addOption("r", false, "Perform a rolling split of an existing region");
+ opt.addOption(OptionBuilder.withArgName("count").hasArg().withDescription(
+ "Max outstanding splits that have unfinished major compactions")
+ .create("o"));
+ opt.addOption(null, "risky", false,
+ "Skip verification steps to complete quickly."
+ + "STRONGLY DISCOURAGED for production systems. ");
+ CommandLine cmd = new GnuParser().parse(opt, args);
+
+ if (cmd.hasOption("D")) {
+ for (String confOpt : cmd.getOptionValues("D")) {
+ String[] kv = confOpt.split("=", 2);
+ if (kv.length == 2) {
+ conf.set(kv[0], kv[1]);
+ LOG.debug("-D configuration override: " + kv[0] + "=" + kv[1]);
+ } else {
+ throw new ParseException("-D option format invalid: " + confOpt);
+ }
+ }
+ }
+
+ if (cmd.hasOption("risky")) {
+ conf.setBoolean("split.verify", false);
+ }
+
+ boolean createTable = cmd.hasOption("c") && cmd.hasOption("f");
+ boolean rollingSplit = cmd.hasOption("r");
+ boolean oneOperOnly = createTable ^ rollingSplit;
+
+ if (1 != cmd.getArgList().size() || !oneOperOnly || cmd.hasOption("h")) {
+ new HelpFormatter().printHelp("RegionSplitter <TABLE>", opt);
+ return;
+ }
+ String tableName = cmd.getArgs()[0];
+
+ if (createTable) {
+ conf.set("split.count", cmd.getOptionValue("c"));
+ createPresplitTable(tableName, cmd.getOptionValue("f").split(":"), conf);
+ }
+
+ if (rollingSplit) {
+ if (cmd.hasOption("o")) {
+ conf.set("split.outstanding", cmd.getOptionValue("o"));
+ }
+ rollingSplit(tableName, conf);
+ }
+ }
+
+ static void createPresplitTable(String tableName, String[] columnFamilies,
+ Configuration conf) throws IOException, InterruptedException {
+ Class<? extends SplitAlgorithm> splitClass = conf.getClass(
+ "split.algorithm", MD5StringSplit.class, SplitAlgorithm.class);
+ SplitAlgorithm splitAlgo;
+ try {
+ splitAlgo = splitClass.newInstance();
+ } catch (Exception e) {
+ throw new IOException("Problem loading split algorithm: ", e);
+ }
+ final int splitCount = conf.getInt("split.count", 0);
+ Preconditions.checkArgument(splitCount > 1, "Split count must be > 1");
+
+ Preconditions.checkArgument(columnFamilies.length > 0,
+ "Must specify at least one column family. ");
+ LOG.debug("Creating table " + tableName + " with " + columnFamilies.length
+ + " column families. Presplitting to " + splitCount + " regions");
+
+ HTableDescriptor desc = new HTableDescriptor(tableName);
+ for (String cf : columnFamilies) {
+ desc.addFamily(new HColumnDescriptor(Bytes.toBytes(cf)));
+ }
+ HBaseAdmin admin = new HBaseAdmin(conf);
+ Preconditions.checkArgument(!admin.tableExists(tableName),
+ "Table already exists: " + tableName);
+ admin.createTable(desc, splitAlgo.split(splitCount));
+ LOG.debug("Table created! Waiting for regions to show online in META...");
+
+ if (!conf.getBoolean("split.verify", true)) {
+ // NOTE: createTable is synchronous on the table, but not on the regions
+ HTable table = new HTable(tableName);
+ int onlineRegions = 0;
+ while (onlineRegions < splitCount) {
+ onlineRegions = table.getRegionsInfo().size();
+ LOG.debug(onlineRegions + " of " + splitCount + " regions online...");
+ if (onlineRegions < splitCount) {
+ Thread.sleep(10 * 1000); // sleep
+ }
+ }
+ }
+
+ LOG.debug("Finished creating table with " + splitCount + " regions");
+ }
+
+ static void rollingSplit(String tableName, Configuration conf)
+ throws IOException, InterruptedException {
+ Class<? extends SplitAlgorithm> splitClass = conf.getClass(
+ "split.algorithm", MD5StringSplit.class, SplitAlgorithm.class);
+ SplitAlgorithm splitAlgo;
+ try {
+ splitAlgo = splitClass.newInstance();
+ } catch (Exception e) {
+ throw new IOException("Problem loading split algorithm: ", e);
+ }
+ final int minOS = conf.getInt("split.outstanding", 2);
+
+ HTable table = new HTable(conf, tableName);
+
+ // max outstanding splits. default == 50% of servers
+ final int MAX_OUTSTANDING = Math.max(table.getCurrentNrHRS() / 2, minOS);
+
+ Path hbDir = new Path(conf.get(HConstants.HBASE_DIR));
+ Path tableDir = HTableDescriptor.getTableDir(hbDir, table.getTableName());
+ Path splitFile = new Path(tableDir, "_balancedSplit");
+ FileSystem fs = FileSystem.get(conf);
+
+ // get a list of daughter regions to create
+ LinkedList<Pair<byte[], byte[]>> tmpRegionSet = getSplits(table, splitAlgo);
+ LinkedList<Pair<byte[], byte[]>> outstanding = Lists.newLinkedList();
+ int splitCount = 0;
+ final int origCount = tmpRegionSet.size();
+
+ // all splits must compact & we have 1 compact thread, so 2 split
+ // requests to the same RS can stall the outstanding split queue.
+ // To fix, group the regions into an RS pool and round-robin through it
+ LOG.debug("Bucketing regions by regionserver...");
+ TreeMap<HServerAddress, LinkedList<Pair<byte[], byte[]>>> daughterRegions = Maps
+ .newTreeMap();
+ for (Pair<byte[], byte[]> dr : tmpRegionSet) {
+ HServerAddress rsLocation = table.getRegionLocation(dr.getSecond())
+ .getServerAddress();
+ if (!daughterRegions.containsKey(rsLocation)) {
+ LinkedList<Pair<byte[], byte[]>> entry = Lists.newLinkedList();
+ daughterRegions.put(rsLocation, entry);
+ }
+ daughterRegions.get(rsLocation).add(dr);
+ }
+ LOG.debug("Done with bucketing. Split time!");
+ long startTime = System.currentTimeMillis();
+
+ // open the split file and modify it as splits finish
+ FSDataInputStream tmpIn = fs.open(splitFile);
+ byte[] rawData = new byte[tmpIn.available()];
+ tmpIn.readFully(rawData);
+ tmpIn.close();
+ FSDataOutputStream splitOut = fs.create(splitFile);
+ splitOut.write(rawData);
+
+ try {
+ // *** split code ***
+ while (!daughterRegions.isEmpty()) {
+ LOG.debug(daughterRegions.size() + " RS have regions to splt.");
+
+ // round-robin through the RS list
+ for (HServerAddress rsLoc = daughterRegions.firstKey();
+ rsLoc != null;
+ rsLoc = daughterRegions.higherKey(rsLoc)) {
+ Pair<byte[], byte[]> dr = null;
+
+ // find a region in the RS list that hasn't been moved
+ LOG.debug("Finding a region on " + rsLoc);
+ LinkedList<Pair<byte[], byte[]>> regionList = daughterRegions
+ .get(rsLoc);
+ while (!regionList.isEmpty()) {
+ dr = regionList.pop();
+
+ // get current region info
+ byte[] split = dr.getSecond();
+ HRegionLocation regionLoc = table.getRegionLocation(split);
+
+ // if this region moved locations
+ HServerAddress newRs = regionLoc.getServerAddress();
+ if (newRs.compareTo(rsLoc) != 0) {
+ LOG.debug("Region with " + splitAlgo.rowToStr(split)
+ + " moved to " + newRs + ". Relocating...");
+ // relocate it, don't use it right now
+ if (!daughterRegions.containsKey(newRs)) {
+ LinkedList<Pair<byte[], byte[]>> entry = Lists.newLinkedList();
+ daughterRegions.put(newRs, entry);
+ }
+ daughterRegions.get(newRs).add(dr);
+ dr = null;
+ continue;
+ }
+
+ // make sure this region wasn't already split
+ byte[] sk = regionLoc.getRegionInfo().getStartKey();
+ if (sk.length != 0) {
+ if (Bytes.equals(split, sk)) {
+ LOG.debug("Region already split on "
+ + splitAlgo.rowToStr(split) + ". Skipping this region...");
+ dr = null;
+ continue;
+ }
+ byte[] start = dr.getFirst();
+ Preconditions.checkArgument(Bytes.equals(start, sk), splitAlgo
+ .rowToStr(start) + " != " + splitAlgo.rowToStr(sk));
+ }
+
+ // passed all checks! found a good region
+ break;
+ }
+ if (regionList.isEmpty()) {
+ daughterRegions.remove(rsLoc);
+ }
+ if (dr == null)
+ continue;
+
+ // we have a good region, time to split!
+
+ byte[] start = dr.getFirst();
+ byte[] split = dr.getSecond();
+ // request split
+ LOG.debug("Splitting at " + splitAlgo.rowToStr(split));
+ HBaseAdmin admin = new HBaseAdmin(table.getConfiguration());
+ admin.split(table.getTableName(), split);
+
+ if (conf.getBoolean("split.verify", true)) {
+ // wait for one of the daughter regions to come online
+ boolean daughterOnline = false;
+ int daughterSleep = 5; // seconds
+ while (!daughterOnline) {
+ LOG.debug("Waiting for daughter region to come online...");
+ table.clearRegionCache();
+ HRegionInfo hri = table.getRegionLocation(split).getRegionInfo();
+ daughterOnline = Bytes.equals(hri.getStartKey(), split)
+ && !hri.isOffline();
+ daughterSleep = Math.min(daughterSleep * 2, 60);
+ Thread.sleep(daughterSleep * 1000); // sleep
+ }
+ LOG.debug("Daughter region is online.");
+ }
+
+ // mark the region as successfully split.
+ // NOTE: split done, but daughter regions still need to major compact
+ splitOut.writeChars("- " + splitAlgo.rowToStr(dr.getFirst()) + " "
+ + splitAlgo.rowToStr(dr.getSecond()) + "\n");
+ splitCount++;
+ if (splitCount % 10 == 0) {
+ long tDiff = (System.currentTimeMillis() - startTime) / splitCount;
+ LOG.debug("STATUS UPDATE: " + splitCount + " / " + origCount
+ + ". Avg Time / Split = "
+ + org.apache.hadoop.util.StringUtils.formatTime(tDiff));
+ }
+
+ if (conf.getBoolean("split.verify", true)) {
+ // if we have too many outstanding splits, wait for oldest ones to
+ // finish
+ outstanding.addLast(Pair.newPair(start, split));
+ if (outstanding.size() > MAX_OUTSTANDING) {
+ Pair<byte[], byte[]> reg = outstanding.removeFirst();
+ String outStart = splitAlgo.rowToStr(reg.getFirst());
+ String outSplit = splitAlgo.rowToStr(reg.getSecond());
+ LOG.debug("Waiting for " + outStart + " , " + outSplit
+ + " to finish compaction");
+ // when a daughter region is opened, a compaction is triggered
+ // wait until compaction completes for both daughter regions
+ LinkedList<HRegionInfo> check = Lists.newLinkedList();
+ // figure out where this region should be in HDFS
+ check
+ .add(table.getRegionLocation(reg.getFirst()).getRegionInfo());
+ check.add(table.getRegionLocation(reg.getSecond())
+ .getRegionInfo());
+ while (!check.isEmpty()) {
+ // compaction is completed when all reference files are gone
+ for (HRegionInfo hri : check.toArray(new HRegionInfo[] {})) {
+ boolean refFound = false;
+ byte[] sk = hri.getStartKey();
+ if (sk.length == 0)
+ sk = splitAlgo.firstRow();
+ String startKey = splitAlgo.rowToStr(sk);
+ // check every Column Family for that region
+ for (HColumnDescriptor c : hri.getTableDesc().getFamilies()) {
+ Path cfDir = Store.getStoreHomedir(tableDir, hri
+ .getEncodedName(), c.getName());
+ if (fs.exists(cfDir)) {
+ for (FileStatus file : fs.listStatus(cfDir)) {
+ refFound |= StoreFile.isReference(file.getPath());
+ if (refFound) {
+ LOG.debug("Reference still exists for " + startKey
+ + " at " + file.getPath());
+ break;
+ }
+ }
+ }
+ if (refFound)
+ break;
+ }
+ if (!refFound) {
+ check.remove(hri);
+ LOG.debug("- finished compaction of " + startKey);
+ }
+ }
+ // sleep in between requests
+ if (!check.isEmpty()) {
+ LOG.debug("Waiting for " + check.size() + " compactions");
+ Thread.sleep(30 * 1000);
+ }
+ }
+ }
+ }
+ }
+ }
+ LOG.debug("All regions have been sucesfully split!");
+ } finally {
+ long tDiff = System.currentTimeMillis() - startTime;
+ LOG.debug("TOTAL TIME = "
+ + org.apache.hadoop.util.StringUtils.formatTime(tDiff));
+ LOG.debug("Splits = " + splitCount);
+ LOG.debug("Avg Time / Split = "
+ + org.apache.hadoop.util.StringUtils.formatTime(tDiff / splitCount));
+
+ splitOut.close();
+ }
+ fs.delete(splitFile, false);
+ }
+
+ static LinkedList<Pair<byte[], byte[]>> getSplits(HTable table,
+ SplitAlgorithm splitAlgo) throws IOException {
+ Path hbDir = new Path(table.getConfiguration().get(HConstants.HBASE_DIR));
+ Path tableDir = HTableDescriptor.getTableDir(hbDir, table.getTableName());
+ Path splitFile = new Path(tableDir, "_balancedSplit");
+ FileSystem fs = FileSystem.get(table.getConfiguration());
+
+ // using strings because (new byte[]{0}).equals(new byte[]{0}) == false
+ Set<Pair<String, String>> daughterRegions = Sets.newHashSet();
+
+ // does a split file exist?
+ if (!fs.exists(splitFile)) {
+ // NO = fresh start. calculate splits to make
+ LOG.debug("No _balancedSplit file. Calculating splits...");
+
+ // query meta for all regions in the table
+ Set<Pair<byte[], byte[]>> rows = Sets.newHashSet();
+ Pair<byte[][], byte[][]> tmp = table.getStartEndKeys();
+ Preconditions.checkArgument(
+ tmp.getFirst().length == tmp.getSecond().length,
+ "Start and End rows should be equivalent");
+ for (int i = 0; i < tmp.getFirst().length; ++i) {
+ byte[] start = tmp.getFirst()[i], end = tmp.getSecond()[i];
+ if (start.length == 0)
+ start = splitAlgo.firstRow();
+ if (end.length == 0)
+ end = splitAlgo.lastRow();
+ rows.add(Pair.newPair(start, end));
+ }
+ LOG.debug("Table " + Bytes.toString(table.getTableName()) + " has "
+ + rows.size() + " regions that will be split.");
+
+ // prepare the split file
+ Path tmpFile = new Path(tableDir, "_balancedSplit_prepare");
+ FSDataOutputStream tmpOut = fs.create(tmpFile);
+
+ // calculate all the splits == [daughterRegions] = [(start, splitPoint)]
+ for (Pair<byte[], byte[]> r : rows) {
+ byte[] splitPoint = splitAlgo.split(r.getFirst(), r.getSecond());
+ String startStr = splitAlgo.rowToStr(r.getFirst());
+ String splitStr = splitAlgo.rowToStr(splitPoint);
+ daughterRegions.add(Pair.newPair(startStr, splitStr));
+ LOG.debug("Will Split [" + startStr + " , "
+ + splitAlgo.rowToStr(r.getSecond()) + ") at " + splitStr);
+ tmpOut.writeChars("+ " + startStr + splitAlgo.separator() + splitStr
+ + "\n");
+ }
+ tmpOut.close();
+ fs.rename(tmpFile, splitFile);
+ } else {
+ LOG.debug("_balancedSplit file found. Replay log to restore state...");
+ FSUtils.recoverFileLease(fs, splitFile, table.getConfiguration());
+
+ // parse split file and process remaining splits
+ FSDataInputStream tmpIn = fs.open(splitFile);
+ StringBuilder sb = new StringBuilder(tmpIn.available());
+ while (tmpIn.available() > 0) {
+ sb.append(tmpIn.readChar());
+ }
+ tmpIn.close();
+ for (String line : sb.toString().split("\n")) {
+ String[] cmd = line.split(splitAlgo.separator());
+ Preconditions.checkArgument(3 == cmd.length);
+ byte[] start = splitAlgo.strToRow(cmd[1]);
+ String startStr = splitAlgo.rowToStr(start);
+ byte[] splitPoint = splitAlgo.strToRow(cmd[2]);
+ String splitStr = splitAlgo.rowToStr(splitPoint);
+ Pair<String, String> r = Pair.newPair(startStr, splitStr);
+ if (cmd[0].equals("+")) {
+ LOG.debug("Adding: " + r);
+ daughterRegions.add(r);
+ } else {
+ LOG.debug("Removing: " + r);
+ Preconditions.checkArgument(cmd[0].equals("-"),
+ "Unknown option: " + cmd[0]);
+ Preconditions.checkState(daughterRegions.contains(r),
+ "Missing row: " + r);
+ daughterRegions.remove(r);
+ }
+ }
+ LOG.debug("Done reading. " + daughterRegions.size() + " regions left.");
+ }
+ LinkedList<Pair<byte[], byte[]>> ret = Lists.newLinkedList();
+ for (Pair<String, String> r : daughterRegions) {
+ ret.add(Pair.newPair(splitAlgo.strToRow(r.getFirst()), splitAlgo
+ .strToRow(r.getSecond())));
+ }
+ return ret;
+ }
+
+ /**
+ * MD5StringSplit is the default {@link SplitAlgorithm} for creating pre-split
+ * tables. The format of MD5StringSplit is the ASCII representation of an MD5
+ * checksum. Row are long values in the range <b>"00000000" => "7FFFFFFF"</b>
+ * and are left-padded with zeros to keep the same order lexographically as if
+ * they were binary.
+ */
+ public static class MD5StringSplit implements SplitAlgorithm {
+ final static String MAXMD5 = "7FFFFFFF";
+ final static BigInteger MAXMD5_INT = new BigInteger(MAXMD5, 16);
+ final static int rowComparisonLength = MAXMD5.length();
+
+ public byte[] split(byte[] start, byte[] end) {
+ BigInteger s = convertToBigInteger(start);
+ BigInteger e = convertToBigInteger(end);
+ Preconditions.checkArgument(!e.equals(BigInteger.ZERO));
+ return convertToByte(split2(s, e));
+ }
+
+ public byte[][] split(int n) {
+ BigInteger[] splits = new BigInteger[n - 1];
+ BigInteger sizeOfEachSplit = MAXMD5_INT.divide(BigInteger.valueOf(n));
+ for (int i = 1; i < n; i++) {
+ // NOTE: this means the last region gets all the slop.
+ // This is not a big deal if we're assuming n << MAXMD5
+ splits[i - 1] = sizeOfEachSplit.multiply(BigInteger.valueOf(i));
+ }
+ return convertToBytes(splits);
+ }
+
+ public byte[] firstRow() {
+ return convertToByte(BigInteger.ZERO);
+ }
+
+ public byte[] lastRow() {
+ return convertToByte(MAXMD5_INT);
+ }
+
+ public byte[] strToRow(String in) {
+ return convertToByte(new BigInteger(in, 16));
+ }
+
+ public String rowToStr(byte[] row) {
+ return Bytes.toStringBinary(row);
+ }
+
+ public String separator() {
+ return " ";
+ }
+
+ static BigInteger split2(BigInteger minValue, BigInteger maxValue) {
+ return maxValue.add(minValue).divide(BigInteger.valueOf(2));
+ }
+
+ /**
+ * Returns an array of bytes corresponding to an array of BigIntegers
+ *
+ * @param bigIntegers
+ * @return bytes corresponding to the bigIntegers
+ */
+ static byte[][] convertToBytes(BigInteger[] bigIntegers) {
+ byte[][] returnBytes = new byte[bigIntegers.length][];
+ for (int i = 0; i < bigIntegers.length; i++) {
+ returnBytes[i] = convertToByte(bigIntegers[i]);
+ }
+ return returnBytes;
+ }
+
+ /**
+ * Returns the bytes corresponding to the BigInteger
+ *
+ * @param bigInteger
+ * @return byte corresponding to input BigInteger
+ */
+ static byte[] convertToByte(BigInteger bigInteger) {
+ String bigIntegerString = bigInteger.toString(16);
+ bigIntegerString = StringUtils.leftPad(bigIntegerString,
+ rowComparisonLength, '0');
+ return Bytes.toBytes(bigIntegerString);
+ }
+
+ /**
+ * Returns the BigInteger represented by thebyte array
+ *
+ * @param row
+ * @return the corresponding BigInteger
+ */
+ static BigInteger convertToBigInteger(byte[] row) {
+ return (row.length > 0) ? new BigInteger(Bytes.toString(row), 16)
+ : BigInteger.ZERO;
+ }
+ }
+
+}