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Server functionality for HBase
/**
* 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.mapreduce;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.CellUtil;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.KeyValueUtil;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.classification.InterfaceStability;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Delete;
import org.apache.hadoop.hbase.client.Mutation;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.RegionLocator;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.regionserver.wal.WALCellCodec;
import org.apache.hadoop.hbase.regionserver.wal.WALEdit;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.wal.WALKey;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.GenericOptionsParser;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import java.io.IOException;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Map;
import java.util.TreeMap;
/**
* A tool to replay WAL files as a M/R job.
* The WAL can be replayed for a set of tables or all tables,
* and a timerange can be provided (in milliseconds).
* The WAL is filtered to the passed set of tables and the output
* can optionally be mapped to another set of tables.
*
* WAL replay can also generate HFiles for later bulk importing,
* in that case the WAL is replayed for a single table only.
*/
@InterfaceAudience.Public
@InterfaceStability.Stable
public class WALPlayer extends Configured implements Tool {
private static final Log LOG = LogFactory.getLog(WALPlayer.class);
final static String NAME = "WALPlayer";
final static String BULK_OUTPUT_CONF_KEY = "wal.bulk.output";
final static String TABLES_KEY = "wal.input.tables";
final static String TABLE_MAP_KEY = "wal.input.tablesmap";
// This relies on Hadoop Configuration to handle warning about deprecated configs and
// to set the correct non-deprecated configs when an old one shows up.
static {
Configuration.addDeprecation("hlog.bulk.output", BULK_OUTPUT_CONF_KEY);
Configuration.addDeprecation("hlog.input.tables", TABLES_KEY);
Configuration.addDeprecation("hlog.input.tablesmap", TABLE_MAP_KEY);
Configuration.addDeprecation(HLogInputFormat.START_TIME_KEY, WALInputFormat.START_TIME_KEY);
Configuration.addDeprecation(HLogInputFormat.END_TIME_KEY, WALInputFormat.END_TIME_KEY);
}
/**
* A mapper that just writes out KeyValues.
* This one can be used together with {@link KeyValueSortReducer}
*/
static class WALKeyValueMapper
extends Mapper {
private byte[] table;
@Override
public void map(WALKey key, WALEdit value,
Context context)
throws IOException {
try {
// skip all other tables
if (Bytes.equals(table, key.getTablename().getName())) {
for (Cell cell : value.getCells()) {
KeyValue kv = KeyValueUtil.ensureKeyValueTypeForMR(cell);
if (WALEdit.isMetaEditFamily(kv.getFamily())) continue;
context.write(new ImmutableBytesWritable(kv.getRow()), kv);
}
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}
@Override
public void setup(Context context) throws IOException {
// only a single table is supported when HFiles are generated with HFileOutputFormat
String tables[] = context.getConfiguration().getStrings(TABLES_KEY);
if (tables == null || tables.length != 1) {
// this can only happen when WALMapper is used directly by a class other than WALPlayer
throw new IOException("Exactly one table must be specified for bulk HFile case.");
}
table = Bytes.toBytes(tables[0]);
}
}
/**
* A mapper that writes out {@link Mutation} to be directly applied to
* a running HBase instance.
*/
protected static class WALMapper
extends Mapper {
private Map tables = new TreeMap();
@Override
public void map(WALKey key, WALEdit value, Context context)
throws IOException {
try {
if (tables.isEmpty() || tables.containsKey(key.getTablename())) {
TableName targetTable = tables.isEmpty() ?
key.getTablename() :
tables.get(key.getTablename());
ImmutableBytesWritable tableOut = new ImmutableBytesWritable(targetTable.getName());
Put put = null;
Delete del = null;
Cell lastCell = null;
for (Cell cell : value.getCells()) {
// filtering WAL meta entries
if (WALEdit.isMetaEditFamily(cell.getFamily())) continue;
// Allow a subclass filter out this cell.
if (filter(context, cell)) {
// A WALEdit may contain multiple operations (HBASE-3584) and/or
// multiple rows (HBASE-5229).
// Aggregate as much as possible into a single Put/Delete
// operation before writing to the context.
if (lastCell == null || lastCell.getTypeByte() != cell.getTypeByte()
|| !CellUtil.matchingRow(lastCell, cell)) {
// row or type changed, write out aggregate KVs.
if (put != null) context.write(tableOut, put);
if (del != null) context.write(tableOut, del);
if (CellUtil.isDelete(cell)) {
del = new Delete(cell.getRow());
} else {
put = new Put(cell.getRow());
}
}
if (CellUtil.isDelete(cell)) {
del.addDeleteMarker(cell);
} else {
put.add(cell);
}
}
lastCell = cell;
}
// write residual KVs
if (put != null) context.write(tableOut, put);
if (del != null) context.write(tableOut, del);
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}
/**
* @param cell
* @return Return true if we are to emit this cell.
*/
protected boolean filter(Context context, final Cell cell) {
return true;
}
@Override
public void setup(Context context) throws IOException {
String[] tableMap = context.getConfiguration().getStrings(TABLE_MAP_KEY);
String[] tablesToUse = context.getConfiguration().getStrings(TABLES_KEY);
if (tablesToUse == null && tableMap == null) {
// Then user wants all tables.
} else if (tablesToUse == null || tableMap == null || tablesToUse.length != tableMap.length) {
// this can only happen when WALMapper is used directly by a class other than WALPlayer
throw new IOException("No tables or incorrect table mapping specified.");
}
int i = 0;
if (tablesToUse != null) {
for (String table : tablesToUse) {
tables.put(TableName.valueOf(table),
TableName.valueOf(tableMap[i++]));
}
}
}
}
/**
* @param conf The {@link Configuration} to use.
*/
public WALPlayer(Configuration conf) {
super(conf);
}
void setupTime(Configuration conf, String option) throws IOException {
String val = conf.get(option);
if (null == val) return;
long ms;
try {
// first try to parse in user friendly form
ms = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SS").parse(val).getTime();
} catch (ParseException pe) {
try {
// then see if just a number of ms's was specified
ms = Long.parseLong(val);
} catch (NumberFormatException nfe) {
throw new IOException(option
+ " must be specified either in the form 2001-02-20T16:35:06.99 "
+ "or as number of milliseconds");
}
}
conf.setLong(option, ms);
}
/**
* Sets up the actual job.
*
* @param args The command line parameters.
* @return The newly created job.
* @throws IOException When setting up the job fails.
*/
public Job createSubmittableJob(String[] args)
throws IOException {
Configuration conf = getConf();
setupTime(conf, HLogInputFormat.START_TIME_KEY);
setupTime(conf, HLogInputFormat.END_TIME_KEY);
Path inputDir = new Path(args[0]);
String[] tables = args[1].split(",");
String[] tableMap;
if (args.length > 2) {
tableMap = args[2].split(",");
if (tableMap.length != tables.length) {
throw new IOException("The same number of tables and mapping must be provided.");
}
} else {
// if not mapping is specified map each table to itself
tableMap = tables;
}
conf.setStrings(TABLES_KEY, tables);
conf.setStrings(TABLE_MAP_KEY, tableMap);
Job job = new Job(conf, NAME + "_" + inputDir);
job.setJarByClass(WALPlayer.class);
FileInputFormat.setInputPaths(job, inputDir);
job.setInputFormatClass(WALInputFormat.class);
job.setMapOutputKeyClass(ImmutableBytesWritable.class);
String hfileOutPath = conf.get(BULK_OUTPUT_CONF_KEY);
if (hfileOutPath != null) {
// the bulk HFile case
if (tables.length != 1) {
throw new IOException("Exactly one table must be specified for the bulk export option");
}
TableName tableName = TableName.valueOf(tables[0]);
job.setMapperClass(WALKeyValueMapper.class);
job.setReducerClass(KeyValueSortReducer.class);
Path outputDir = new Path(hfileOutPath);
FileOutputFormat.setOutputPath(job, outputDir);
job.setMapOutputValueClass(KeyValue.class);
try (Connection conn = ConnectionFactory.createConnection(conf);
Table table = conn.getTable(tableName);
RegionLocator regionLocator = conn.getRegionLocator(tableName)) {
HFileOutputFormat2.configureIncrementalLoad(job, table.getTableDescriptor(), regionLocator);
}
TableMapReduceUtil.addDependencyJarsForClasses(job.getConfiguration(),
com.google.common.base.Preconditions.class);
} else {
// output to live cluster
job.setMapperClass(WALMapper.class);
job.setOutputFormatClass(MultiTableOutputFormat.class);
TableMapReduceUtil.addDependencyJars(job);
TableMapReduceUtil.initCredentials(job);
// No reducers.
job.setNumReduceTasks(0);
}
String codecCls = WALCellCodec.getWALCellCodecClass(conf);
try {
TableMapReduceUtil.addDependencyJarsForClasses(job.getConfiguration(), Class.forName(codecCls));
} catch (Exception e) {
throw new IOException("Cannot determine wal codec class " + codecCls, e);
}
return job;
}
/*
* @param errorMsg Error message. Can be null.
*/
private void usage(final String errorMsg) {
if (errorMsg != null && errorMsg.length() > 0) {
System.err.println("ERROR: " + errorMsg);
}
System.err.println("Usage: " + NAME + " [options] []");
System.err.println("Read all WAL entries for .");
System.err.println("If no tables (\"\") are specific, all tables are imported.");
System.err.println("(Careful, even -ROOT- and hbase:meta entries will be imported in that case.)");
System.err.println("Otherwise is a comma separated list of tables.\n");
System.err.println("The WAL entries can be mapped to new set of tables via .");
System.err.println(" is a command separated list of targettables.");
System.err.println("If specified, each table in must have a mapping.\n");
System.err.println("By default " + NAME + " will load data directly into HBase.");
System.err.println("To generate HFiles for a bulk data load instead, pass the option:");
System.err.println(" -D" + BULK_OUTPUT_CONF_KEY + "=/path/for/output");
System.err.println(" (Only one table can be specified, and no mapping is allowed!)");
System.err.println("Other options: (specify time range to WAL edit to consider)");
System.err.println(" -D" + WALInputFormat.START_TIME_KEY + "=[date|ms]");
System.err.println(" -D" + WALInputFormat.END_TIME_KEY + "=[date|ms]");
System.err.println("For performance also consider the following options:\n"
+ " -Dmapreduce.map.speculative=false\n"
+ " -Dmapreduce.reduce.speculative=false");
}
/**
* Main entry point.
*
* @param args The command line parameters.
* @throws Exception When running the job fails.
*/
public static void main(String[] args) throws Exception {
int ret = ToolRunner.run(new WALPlayer(HBaseConfiguration.create()), args);
System.exit(ret);
}
@Override
public int run(String[] args) throws Exception {
String[] otherArgs = new GenericOptionsParser(getConf(), args).getRemainingArgs();
if (otherArgs.length < 2) {
usage("Wrong number of arguments: " + otherArgs.length);
System.exit(-1);
}
Job job = createSubmittableJob(otherArgs);
return job.waitForCompletion(true) ? 0 : 1;
}
}