HBASE-5166 MultiThreaded Table Mapper analogous to MultiThreaded Mapper in hadoop
git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1293098 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Michael Stack
parent
a01166ec92
commit
ce71b8a1bc
|
|
@ -0,0 +1,252 @@
|
|||
/**
|
||||
* 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 java.io.IOException;
|
||||
import java.util.concurrent.ExecutorService;
|
||||
import java.util.concurrent.Executors;
|
||||
|
||||
import org.apache.commons.logging.Log;
|
||||
import org.apache.commons.logging.LogFactory;
|
||||
import org.apache.hadoop.conf.Configuration;
|
||||
import org.apache.hadoop.hbase.client.Result;
|
||||
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
|
||||
import org.apache.hadoop.mapreduce.Counter;
|
||||
import org.apache.hadoop.mapreduce.InputSplit;
|
||||
import org.apache.hadoop.mapreduce.Job;
|
||||
import org.apache.hadoop.mapreduce.JobContext;
|
||||
import org.apache.hadoop.mapreduce.Mapper;
|
||||
import org.apache.hadoop.mapreduce.RecordReader;
|
||||
import org.apache.hadoop.mapreduce.RecordWriter;
|
||||
import org.apache.hadoop.mapreduce.StatusReporter;
|
||||
import org.apache.hadoop.mapreduce.TaskAttemptContext;
|
||||
import org.apache.hadoop.util.ReflectionUtils;
|
||||
|
||||
|
||||
/**
|
||||
* Multithreaded implementation for @link org.apache.hbase.mapreduce.TableMapper
|
||||
* <p>
|
||||
* It can be used instead when the Map operation is not CPU
|
||||
* bound in order to improve throughput.
|
||||
* <p>
|
||||
* Mapper implementations using this MapRunnable must be thread-safe.
|
||||
* <p>
|
||||
* The Map-Reduce job has to be configured with the mapper to use via
|
||||
* {@link #setMapperClass(Configuration, Class)} and
|
||||
* the number of thread the thread-pool can use with the
|
||||
* {@link #getNumberOfThreads(Configuration) method. The default
|
||||
* value is 10 threads.
|
||||
* <p>
|
||||
*/
|
||||
|
||||
public class MultithreadedTableMapper<K2, V2> extends TableMapper<K2, V2> {
|
||||
private static final Log LOG = LogFactory.getLog(MultithreadedTableMapper.class);
|
||||
private Class<? extends Mapper<ImmutableBytesWritable, Result,K2,V2>> mapClass;
|
||||
private Context outer;
|
||||
private ExecutorService executor;
|
||||
public static final String NUMBER_OF_THREADS = "hbase.mapreduce.multithreadedmapper.threads";
|
||||
public static final String MAPPER_CLASS = "hbase.mapreduce.multithreadedmapper.mapclass";
|
||||
|
||||
/**
|
||||
* The number of threads in the thread pool that will run the map function.
|
||||
* @param job the job
|
||||
* @return the number of threads
|
||||
*/
|
||||
public static int getNumberOfThreads(JobContext job) {
|
||||
return job.getConfiguration().
|
||||
getInt(NUMBER_OF_THREADS, 10);
|
||||
}
|
||||
|
||||
/**
|
||||
* Set the number of threads in the pool for running maps.
|
||||
* @param job the job to modify
|
||||
* @param threads the new number of threads
|
||||
*/
|
||||
public static void setNumberOfThreads(Job job, int threads) {
|
||||
job.getConfiguration().setInt(NUMBER_OF_THREADS,
|
||||
threads);
|
||||
}
|
||||
|
||||
/**
|
||||
* Get the application's mapper class.
|
||||
* @param <K2> the map's output key type
|
||||
* @param <V2> the map's output value type
|
||||
* @param job the job
|
||||
* @return the mapper class to run
|
||||
*/
|
||||
@SuppressWarnings("unchecked")
|
||||
public static <K2,V2>
|
||||
Class<Mapper<ImmutableBytesWritable, Result,K2,V2>> getMapperClass(JobContext job) {
|
||||
return (Class<Mapper<ImmutableBytesWritable, Result,K2,V2>>)
|
||||
job.getConfiguration().getClass( MAPPER_CLASS,
|
||||
Mapper.class);
|
||||
}
|
||||
|
||||
/**
|
||||
* Set the application's mapper class.
|
||||
* @param <K2> the map output key type
|
||||
* @param <V2> the map output value type
|
||||
* @param job the job to modify
|
||||
* @param cls the class to use as the mapper
|
||||
*/
|
||||
public static <K2,V2>
|
||||
void setMapperClass(Job job,
|
||||
Class<? extends Mapper<ImmutableBytesWritable, Result,K2,V2>> cls) {
|
||||
if (MultithreadedTableMapper.class.isAssignableFrom(cls)) {
|
||||
throw new IllegalArgumentException("Can't have recursive " +
|
||||
"MultithreadedTableMapper instances.");
|
||||
}
|
||||
job.getConfiguration().setClass(MAPPER_CLASS,
|
||||
cls, Mapper.class);
|
||||
}
|
||||
|
||||
/**
|
||||
* Run the application's maps using a thread pool.
|
||||
*/
|
||||
@Override
|
||||
public void run(Context context) throws IOException, InterruptedException {
|
||||
outer = context;
|
||||
int numberOfThreads = getNumberOfThreads(context);
|
||||
mapClass = getMapperClass(context);
|
||||
if (LOG.isDebugEnabled()) {
|
||||
LOG.debug("Configuring multithread runner to use " + numberOfThreads +
|
||||
" threads");
|
||||
}
|
||||
executor = Executors.newFixedThreadPool(numberOfThreads);
|
||||
for(int i=0; i < numberOfThreads; ++i) {
|
||||
MapRunner thread = new MapRunner(context);
|
||||
executor.execute(thread);
|
||||
}
|
||||
executor.shutdown();
|
||||
while (!executor.isTerminated()) {
|
||||
// wait till all the threads are done
|
||||
Thread.sleep(1000);
|
||||
}
|
||||
}
|
||||
|
||||
private class SubMapRecordReader
|
||||
extends RecordReader<ImmutableBytesWritable, Result> {
|
||||
private ImmutableBytesWritable key;
|
||||
private Result value;
|
||||
private Configuration conf;
|
||||
|
||||
@Override
|
||||
public void close() throws IOException {
|
||||
}
|
||||
|
||||
@Override
|
||||
public float getProgress() throws IOException, InterruptedException {
|
||||
return 0;
|
||||
}
|
||||
|
||||
@Override
|
||||
public void initialize(InputSplit split,
|
||||
TaskAttemptContext context
|
||||
) throws IOException, InterruptedException {
|
||||
conf = context.getConfiguration();
|
||||
}
|
||||
|
||||
@Override
|
||||
public boolean nextKeyValue() throws IOException, InterruptedException {
|
||||
synchronized (outer) {
|
||||
if (!outer.nextKeyValue()) {
|
||||
return false;
|
||||
}
|
||||
key = ReflectionUtils.copy(outer.getConfiguration(),
|
||||
outer.getCurrentKey(), key);
|
||||
value = ReflectionUtils.copy(conf, outer.getCurrentValue(), value);
|
||||
return true;
|
||||
}
|
||||
}
|
||||
|
||||
public ImmutableBytesWritable getCurrentKey() {
|
||||
return key;
|
||||
}
|
||||
|
||||
@Override
|
||||
public Result getCurrentValue() {
|
||||
return value;
|
||||
}
|
||||
}
|
||||
|
||||
private class SubMapRecordWriter extends RecordWriter<K2,V2> {
|
||||
|
||||
@Override
|
||||
public void close(TaskAttemptContext context) throws IOException,
|
||||
InterruptedException {
|
||||
}
|
||||
|
||||
@Override
|
||||
public void write(K2 key, V2 value) throws IOException,
|
||||
InterruptedException {
|
||||
synchronized (outer) {
|
||||
outer.write(key, value);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
private class SubMapStatusReporter extends StatusReporter {
|
||||
|
||||
@Override
|
||||
public Counter getCounter(Enum<?> name) {
|
||||
return outer.getCounter(name);
|
||||
}
|
||||
|
||||
@Override
|
||||
public Counter getCounter(String group, String name) {
|
||||
return outer.getCounter(group, name);
|
||||
}
|
||||
|
||||
@Override
|
||||
public void progress() {
|
||||
outer.progress();
|
||||
}
|
||||
|
||||
@Override
|
||||
public void setStatus(String status) {
|
||||
outer.setStatus(status);
|
||||
}
|
||||
}
|
||||
|
||||
private class MapRunner implements Runnable {
|
||||
private Mapper<ImmutableBytesWritable, Result, K2,V2> mapper;
|
||||
private Context subcontext;
|
||||
private Throwable throwable;
|
||||
|
||||
MapRunner(Context context) throws IOException, InterruptedException {
|
||||
mapper = ReflectionUtils.newInstance(mapClass,
|
||||
context.getConfiguration());
|
||||
subcontext = new Context(outer.getConfiguration(),
|
||||
outer.getTaskAttemptID(),
|
||||
new SubMapRecordReader(),
|
||||
new SubMapRecordWriter(),
|
||||
context.getOutputCommitter(),
|
||||
new SubMapStatusReporter(),
|
||||
outer.getInputSplit());
|
||||
}
|
||||
|
||||
@Override
|
||||
public void run() {
|
||||
try {
|
||||
mapper.run(subcontext);
|
||||
} catch (Throwable ie) {
|
||||
throwable = ie;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,260 @@
|
|||
/**
|
||||
* 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 java.io.File;
|
||||
import java.io.IOException;
|
||||
import java.util.Map;
|
||||
import java.util.NavigableMap;
|
||||
|
||||
import org.apache.commons.logging.Log;
|
||||
import org.apache.commons.logging.LogFactory;
|
||||
import org.apache.hadoop.conf.Configuration;
|
||||
import org.apache.hadoop.fs.FileUtil;
|
||||
import org.apache.hadoop.fs.Path;
|
||||
import org.apache.hadoop.hbase.*;
|
||||
import org.apache.hadoop.hbase.client.HBaseAdmin;
|
||||
import org.apache.hadoop.hbase.client.HTable;
|
||||
import org.apache.hadoop.hbase.client.Put;
|
||||
import org.apache.hadoop.hbase.client.Result;
|
||||
import org.apache.hadoop.hbase.client.ResultScanner;
|
||||
import org.apache.hadoop.hbase.client.Scan;
|
||||
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
|
||||
import org.apache.hadoop.hbase.util.Bytes;
|
||||
import org.apache.hadoop.mapreduce.Job;
|
||||
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
|
||||
import org.junit.AfterClass;
|
||||
import org.junit.BeforeClass;
|
||||
import org.junit.Test;
|
||||
import org.junit.experimental.categories.Category;
|
||||
|
||||
import static org.junit.Assert.fail;
|
||||
import static org.junit.Assert.assertTrue;
|
||||
|
||||
/**
|
||||
* Test Map/Reduce job over HBase tables. The map/reduce process we're testing
|
||||
* on our tables is simple - take every row in the table, reverse the value of
|
||||
* a particular cell, and write it back to the table.
|
||||
*/
|
||||
@Category(LargeTests.class)
|
||||
public class TestMulitthreadedTableMapper {
|
||||
private static final Log LOG = LogFactory.getLog(TestMulitthreadedTableMapper.class);
|
||||
private static final HBaseTestingUtility UTIL =
|
||||
new HBaseTestingUtility();
|
||||
static final String MULTI_REGION_TABLE_NAME = "mrtest";
|
||||
static final byte[] INPUT_FAMILY = Bytes.toBytes("contents");
|
||||
static final byte[] OUTPUT_FAMILY = Bytes.toBytes("text");
|
||||
static final int NUMBER_OF_THREADS = 10;
|
||||
|
||||
@BeforeClass
|
||||
public static void beforeClass() throws Exception {
|
||||
HTableDescriptor desc = new HTableDescriptor(MULTI_REGION_TABLE_NAME);
|
||||
desc.addFamily(new HColumnDescriptor(INPUT_FAMILY));
|
||||
desc.addFamily(new HColumnDescriptor(OUTPUT_FAMILY));
|
||||
UTIL.startMiniCluster();
|
||||
HBaseAdmin admin = new HBaseAdmin(UTIL.getConfiguration());
|
||||
admin.createTable(desc, HBaseTestingUtility.KEYS);
|
||||
UTIL.startMiniMapReduceCluster();
|
||||
}
|
||||
|
||||
@AfterClass
|
||||
public static void afterClass() throws Exception {
|
||||
UTIL.shutdownMiniMapReduceCluster();
|
||||
UTIL.shutdownMiniCluster();
|
||||
}
|
||||
|
||||
/**
|
||||
* Pass the given key and processed record reduce
|
||||
*/
|
||||
public static class ProcessContentsMapper
|
||||
extends TableMapper<ImmutableBytesWritable, Put> {
|
||||
|
||||
/**
|
||||
* Pass the key, and reversed value to reduce
|
||||
*
|
||||
* @param key
|
||||
* @param value
|
||||
* @param context
|
||||
* @throws IOException
|
||||
*/
|
||||
public void map(ImmutableBytesWritable key, Result value,
|
||||
Context context)
|
||||
throws IOException, InterruptedException {
|
||||
if (value.size() != 1) {
|
||||
throw new IOException("There should only be one input column");
|
||||
}
|
||||
Map<byte[], NavigableMap<byte[], NavigableMap<Long, byte[]>>>
|
||||
cf = value.getMap();
|
||||
if(!cf.containsKey(INPUT_FAMILY)) {
|
||||
throw new IOException("Wrong input columns. Missing: '" +
|
||||
Bytes.toString(INPUT_FAMILY) + "'.");
|
||||
}
|
||||
// Get the original value and reverse it
|
||||
String originalValue = new String(value.getValue(INPUT_FAMILY, null),
|
||||
HConstants.UTF8_ENCODING);
|
||||
StringBuilder newValue = new StringBuilder(originalValue);
|
||||
newValue.reverse();
|
||||
// Now set the value to be collected
|
||||
Put outval = new Put(key.get());
|
||||
outval.add(OUTPUT_FAMILY, null, Bytes.toBytes(newValue.toString()));
|
||||
context.write(key, outval);
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Test multithreadedTableMappper map/reduce against a multi-region table
|
||||
* @throws IOException
|
||||
* @throws ClassNotFoundException
|
||||
* @throws InterruptedException
|
||||
*/
|
||||
@Test
|
||||
public void testMultithreadedTableMapper()
|
||||
throws IOException, InterruptedException, ClassNotFoundException {
|
||||
runTestOnTable(new HTable(new Configuration(UTIL.getConfiguration()),
|
||||
MULTI_REGION_TABLE_NAME));
|
||||
}
|
||||
|
||||
private void runTestOnTable(HTable table)
|
||||
throws IOException, InterruptedException, ClassNotFoundException {
|
||||
Job job = null;
|
||||
try {
|
||||
LOG.info("Before map/reduce startup");
|
||||
job = new Job(table.getConfiguration(), "process column contents");
|
||||
job.setNumReduceTasks(1);
|
||||
Scan scan = new Scan();
|
||||
scan.addFamily(INPUT_FAMILY);
|
||||
TableMapReduceUtil.initTableMapperJob(
|
||||
Bytes.toString(table.getTableName()), scan,
|
||||
MultithreadedTableMapper.class, ImmutableBytesWritable.class,
|
||||
Put.class, job);
|
||||
MultithreadedTableMapper.setMapperClass(job, ProcessContentsMapper.class);
|
||||
MultithreadedTableMapper.setNumberOfThreads(job, NUMBER_OF_THREADS);
|
||||
TableMapReduceUtil.initTableReducerJob(
|
||||
Bytes.toString(table.getTableName()),
|
||||
IdentityTableReducer.class, job);
|
||||
FileOutputFormat.setOutputPath(job, new Path("test"));
|
||||
LOG.info("Started " + Bytes.toString(table.getTableName()));
|
||||
job.waitForCompletion(true);
|
||||
LOG.info("After map/reduce completion");
|
||||
// verify map-reduce results
|
||||
verify(Bytes.toString(table.getTableName()));
|
||||
} finally {
|
||||
table.close();
|
||||
if (job != null) {
|
||||
FileUtil.fullyDelete(
|
||||
new File(job.getConfiguration().get("hadoop.tmp.dir")));
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
private void verify(String tableName) throws IOException {
|
||||
HTable table = new HTable(new Configuration(UTIL.getConfiguration()), tableName);
|
||||
boolean verified = false;
|
||||
long pause = UTIL.getConfiguration().getLong("hbase.client.pause", 5 * 1000);
|
||||
int numRetries = UTIL.getConfiguration().getInt("hbase.client.retries.number", 5);
|
||||
for (int i = 0; i < numRetries; i++) {
|
||||
try {
|
||||
LOG.info("Verification attempt #" + i);
|
||||
verifyAttempt(table);
|
||||
verified = true;
|
||||
break;
|
||||
} catch (NullPointerException e) {
|
||||
// If here, a cell was empty. Presume its because updates came in
|
||||
// after the scanner had been opened. Wait a while and retry.
|
||||
LOG.debug("Verification attempt failed: " + e.getMessage());
|
||||
}
|
||||
try {
|
||||
Thread.sleep(pause);
|
||||
} catch (InterruptedException e) {
|
||||
// continue
|
||||
}
|
||||
}
|
||||
assertTrue(verified);
|
||||
table.close();
|
||||
}
|
||||
|
||||
/**
|
||||
* Looks at every value of the mapreduce output and verifies that indeed
|
||||
* the values have been reversed.
|
||||
*
|
||||
* @param table Table to scan.
|
||||
* @throws IOException
|
||||
* @throws NullPointerException if we failed to find a cell value
|
||||
*/
|
||||
private void verifyAttempt(final HTable table)
|
||||
throws IOException, NullPointerException {
|
||||
Scan scan = new Scan();
|
||||
scan.addFamily(INPUT_FAMILY);
|
||||
scan.addFamily(OUTPUT_FAMILY);
|
||||
ResultScanner scanner = table.getScanner(scan);
|
||||
try {
|
||||
for (Result r : scanner) {
|
||||
if (LOG.isDebugEnabled()) {
|
||||
if (r.size() > 2 ) {
|
||||
throw new IOException("Too many results, expected 2 got " +
|
||||
r.size());
|
||||
}
|
||||
}
|
||||
byte[] firstValue = null;
|
||||
byte[] secondValue = null;
|
||||
int count = 0;
|
||||
for(KeyValue kv : r.list()) {
|
||||
if (count == 0) {
|
||||
firstValue = kv.getValue();
|
||||
}else if (count == 1) {
|
||||
secondValue = kv.getValue();
|
||||
}else if (count == 2) {
|
||||
break;
|
||||
}
|
||||
count++;
|
||||
}
|
||||
String first = "";
|
||||
if (firstValue == null) {
|
||||
throw new NullPointerException(Bytes.toString(r.getRow()) +
|
||||
": first value is null");
|
||||
}
|
||||
first = new String(firstValue, HConstants.UTF8_ENCODING);
|
||||
String second = "";
|
||||
if (secondValue == null) {
|
||||
throw new NullPointerException(Bytes.toString(r.getRow()) +
|
||||
": second value is null");
|
||||
}
|
||||
byte[] secondReversed = new byte[secondValue.length];
|
||||
for (int i = 0, j = secondValue.length - 1; j >= 0; j--, i++) {
|
||||
secondReversed[i] = secondValue[j];
|
||||
}
|
||||
second = new String(secondReversed, HConstants.UTF8_ENCODING);
|
||||
if (first.compareTo(second) != 0) {
|
||||
if (LOG.isDebugEnabled()) {
|
||||
LOG.debug("second key is not the reverse of first. row=" +
|
||||
Bytes.toStringBinary(r.getRow()) + ", first value=" + first +
|
||||
", second value=" + second);
|
||||
}
|
||||
fail();
|
||||
}
|
||||
}
|
||||
} finally {
|
||||
scanner.close();
|
||||
}
|
||||
}
|
||||
|
||||
@org.junit.Rule
|
||||
public org.apache.hadoop.hbase.ResourceCheckerJUnitRule cu =
|
||||
new org.apache.hadoop.hbase.ResourceCheckerJUnitRule();
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue