/**
* 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.hdfs;
import java.io.IOException;
import java.util.ArrayList;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.CommonConfigurationKeys;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.metrics2.util.Quantile;
import org.apache.hadoop.metrics2.util.SampleQuantiles;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.junit.Test;
import com.google.common.base.Stopwatch;
/**
* This class tests hflushing concurrently from many threads.
*/
public class TestMultiThreadedHflush {
static final int blockSize = 1024*1024;
private static final int NUM_THREADS = 10;
private static final int WRITE_SIZE = 517;
private static final int NUM_WRITES_PER_THREAD = 1000;
private byte[] toWrite = null;
private final SampleQuantiles quantiles = new SampleQuantiles(
new Quantile[] {
new Quantile(0.50, 0.050),
new Quantile(0.75, 0.025), new Quantile(0.90, 0.010),
new Quantile(0.95, 0.005), new Quantile(0.99, 0.001) });
/*
* creates a file but does not close it
*/
private FSDataOutputStream createFile(FileSystem fileSys, Path name, int repl)
throws IOException {
FSDataOutputStream stm = fileSys.create(name, true, fileSys.getConf()
.getInt(CommonConfigurationKeys.IO_FILE_BUFFER_SIZE_KEY, 4096),
(short) repl, blockSize);
return stm;
}
private void initBuffer(int size) {
long seed = AppendTestUtil.nextLong();
toWrite = AppendTestUtil.randomBytes(seed, size);
}
private class WriterThread extends Thread {
private final FSDataOutputStream stm;
private final AtomicReference<Throwable> thrown;
private final int numWrites;
private final CountDownLatch countdown;
public WriterThread(FSDataOutputStream stm,
AtomicReference<Throwable> thrown,
CountDownLatch countdown, int numWrites) {
this.stm = stm;
this.thrown = thrown;
this.numWrites = numWrites;
this.countdown = countdown;
}
@Override
public void run() {
try {
countdown.await();
for (int i = 0; i < numWrites && thrown.get() == null; i++) {
doAWrite();
}
} catch (Throwable t) {
thrown.compareAndSet(null, t);
}
}
private void doAWrite() throws IOException {
Stopwatch sw = new Stopwatch().start();
stm.write(toWrite);
stm.hflush();
long micros = sw.elapsedTime(TimeUnit.MICROSECONDS);
quantiles.insert(micros);
}
}
/**
* Test case where a bunch of threads are both appending and flushing.
* They all finish before the file is closed.
*/
@Test
public void testMultipleHflushersRepl1() throws Exception {
doTestMultipleHflushers(1);
}
@Test
public void testMultipleHflushersRepl3() throws Exception {
doTestMultipleHflushers(3);
}
private void doTestMultipleHflushers(int repl) throws Exception {
Configuration conf = new Configuration();
Mini