/**
* 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 junit.framework.TestCase;
import java.io.*;
import java.net.*;
import java.util.List;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileUtil.HardLink;
import org.apache.hadoop.fs.BlockLocation;
import org.apache.hadoop.hdfs.protocol.Block;
import org.apache.hadoop.hdfs.protocol.LocatedBlock;
import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
import org.apache.hadoop.hdfs.server.datanode.DataNode;
import org.apache.hadoop.hdfs.server.datanode.FSDataset;
import org.apache.hadoop.hdfs.server.datanode.SimulatedFSDataset;
/**
* This class tests the building blocks that are needed to
* support HDFS appends.
*/
public class TestFileAppend extends TestCase {
static final int blockSize = 1024;
static final int numBlocks = 10;
static final int fileSize = numBlocks * blockSize + 1;
boolean simulatedStorage = false;
private long seed;
private byte[] fileContents = null;
//
// create a buffer that contains the entire test file data.
//
private void initBuffer(int size) {
seed = AppendTestUtil.nextLong();
fileContents = AppendTestUtil.randomBytes(seed, size);
}
/*
* 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("io.file.buffer.size", 4096),
(short)repl, (long)blockSize);
return stm;
}
//
// writes to file but does not close it
//
private void writeFile(FSDataOutputStream stm) throws IOException {
byte[] buffer = AppendTestUtil.randomBytes(seed, fileSize);
stm.write(buffer);
}
//
// verify that the data written to the full blocks are sane
//
private void checkFile(FileSystem fileSys, Path name, int repl)
throws IOException {
boolean done = false;
// wait till all full blocks are confirmed by the datanodes.
while (!done) {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {}
done = true;
BlockLocation[] locations = fileSys.getFileBlockLocations(
fileSys.getFileStatus(name), 0, fileSize);
if (locations.length < numBlocks) {
System.out.println("Number of blocks found " + locations.length);
done = false;
continue;
}
for (int idx = 0; idx < numBlocks; idx++) {
if (locations[idx].getHosts().length < repl) {
System.out.println("Block index " + idx + " not yet replciated.");
done = false;
break;
}
}
}
FSDataInputStream stm = fileSys.open(name);
byte[] expected = new byte[numBlocks * blockSize];
if (simulatedStorage) {
for (int i= 0; i < expected.length; i++) {
expected[i] = SimulatedFSDataset.DEFAULT_DATABYTE;
}
} else {
for (int i= 0; i < expected.length; i++) {
expected[i] = fileContents[i];
}
}
// do a sanity check. Read the file
byte[] actual = new byte[numBlocks * blockSize];
stm.readFully(0, actual);
checkData(actual, 0, expected, "Read 1");
}
private void checkFullFile(FileSystem fs, Path name) throws IOException {
FSDataInputStream stm = fs.open(name);
byte[] actual = new byte[fileSize];
stm.readFully(0, actual);
checkData(actual, 0, fileContents, "Read 2");
stm.close();
}
private void checkData(byte[] actual, int from, byte[] expected, String message) {
for (int idx = 0; idx < actual.length; idx++) {
assertEquals(message+" byte "+(from+idx)+" differs. expected "+
expected[from+idx]+" actual "+actual[idx],
expected[from+idx], actual[idx]);
actual[idx] = 0;
}
}
/**
* Test that copy on write for blocks works correctly
*/
public void testCopyOnWrite() throws IOException {
Configuration conf = new Configuration();
if (simulatedStorage) {
conf.setBoolean(SimulatedFSDataset.CONFIG_PROPERTY_SIMULATED, true);
}
MiniDFSCluster cluster = new MiniDFSCluster(conf, 1, true, null);
FileSystem fs = cluster.getFileSystem();
InetSocketAddress addr = new InetSocketAddress("localhost",
cluster.getNameNodePort());
DFSClient client = new DFSClient(addr, conf);
try {
// create a new file, write to it and close it.
//
Path file1 = new Path("/filestatus.dat");
FSDataOutputStream stm = createFile(fs, file1, 1);
writeFile(stm);
stm.close();
// Get a handle to the datanode
DataNode[] dn = cluster.listDataNodes();
assertTrue("There should be only one datanode but found " + dn.length,
dn.length == 1);
LocatedBlocks locations = client.namenode.getBlockLocations(
file1.toString(), 0, Long.MAX_VALUE);
List<LocatedBlock> blocks = locations.getLocatedBlocks();
FSDataset dataset = (FSDataset) dn[0].data;
//
// Create hard links for a few of the blocks
//
for (int i = 0; i < blocks.size(); i = i + 2) {
Block b = (Block) blocks.get(i).getBlock();
FSDataset fsd = (FSDataset) dataset;
File f = fsd.getFile(b);
File link = new File(f.toString() + ".link");
System.out.println("Creating hardlink for File " + f +
" to " + link);
HardLink.createHardLink(f, link);
}
//
// Detach all blocks. This should remove hardlinks (if any)
//
for (int i = 0; i < blocks.size(); i++) {
Block b = (Block) blocks.get(i).getBlock();
System.out.println("testCopyOnWrite detaching block " + b);
assertTrue("Detaching block " + b + " should have returned true",
dataset.detachBlock(b, 1) == true);
}
// Since the blocks were already detached earlier, these calls should
// return false
//
for (int i = 0; i < blocks.size(); i++) {
Block b = (Block) blocks.get(i).getBlock();
System.out.println("testCopyOnWrite detaching block " + b);
assertTrue("Detaching block " + b + " should have returned false",
dataset.detachBlock(b, 1) == false);
}
} finally {
fs.close();
cluster.shutdown();
}
}
/**
* Test a simple flush on a simple HDFS file.
*/
public void testSimpleFlush() throws IOException {
Configuration conf = new Configuration();
if (simulatedStorage) {
conf.setBoolean(SimulatedFSDataset.CONFIG_PROPERTY_SIMULATED, true);
}
initBuffer(fileSize);
MiniDFSCluster cluster = new MiniDFSCluster(conf, 1, true, null);
FileSystem fs = cluster.getFileSystem();
try {
// create a new file.
Path file1 = new Path("/simpleFlush.dat");
FSDataOutputStream stm = createFile(fs, file1, 1);
System.out.println("Created file simpleFlush.dat");
// write to file
int mid = fileSize/2;
stm.write(fileContents, 0, mid);
stm.sync();
System.out.println("Wrote and Flushed first part of file.");
// write the remainder of the file
stm.write(fileContents, mid, fileSize - mid);
System.out.println("Written second part of file");
stm.sync();
stm.sync();
System.out.println("Wrote and Flushed second part of file.");
// verify that full blocks are sane
checkFile(fs, file1, 1);
stm.close();
System.out.println("Closed file.");
// verify that entire file is good
checkFullFile(fs, file1);
} catch (IOException e) {
System.out.println("Exception :" + e);
throw e;
} catch (Throwable e) {
System.out.println("Throwable :" + e);
e.printStackTrace();
throw new IOException("Throwable : " + e);
} finally {
fs.close();
cluster.shutdown();
}
}
/**
* Test that file data can be flushed.
*/
public void testComplexFlush() throws IOException {
Configuration conf = new Configuration();
if (simulatedStorage) {
conf.setBoolean(SimulatedFSDataset.CONFIG_PROPERTY_SIMULATED, true);
}
initBuffer(fileSize);
MiniDFSCluster cluster = new MiniDFSCluster(conf, 1, true, null);
FileSystem fs = cluster.getFileSystem();
try {
// create a new file.
Path file1 = new Path("/complexFlush.dat");
FSDataOutputStream stm = createFile(fs, file1, 1);
System.out.println("Created file complexFlush.dat");
int start = 0;
for (start = 0; (start + 29) < fileSize; ) {
stm.write(fileContents, start, 29);
stm.sync();
start += 29;
}
stm.write(fileContents, start, fileSize-start);
// verify that full blocks are sane
checkFile(fs, file1, 1);
stm.close();
// verify that entire file is good
checkFullFile(fs, file1);
} catch (IOException e) {
System.out.println("Exception :" + e);
throw e;
} catch (Throwable e) {
System.out.println("Throwable :" + e);
e.printStackTrace();
throw new IOException("Throwable : " + e);
} finally {
fs.close();
cluster.shutdown();
}
}
}