TestFileAppend.java
/**
* 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 static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.junit.jupiter.api.Assertions.fail;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.OutputStream;
import java.net.InetSocketAddress;
import java.util.EnumSet;
import java.util.List;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.TimeoutException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.BlockLocation;
import org.apache.hadoop.fs.CreateFlag;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.HardLink;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.MiniDFSCluster.DataNodeProperties;
import org.apache.hadoop.hdfs.client.HdfsClientConfigKeys;
import org.apache.hadoop.hdfs.protocol.AlreadyBeingCreatedException;
import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
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.DataNodeTestUtils;
import org.apache.hadoop.hdfs.server.datanode.ReplicaBeingWritten;
import org.apache.hadoop.hdfs.server.datanode.ReplicaHandler;
import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsDatasetSpi;
import org.apache.hadoop.hdfs.server.datanode.fsdataset.ReplicaOutputStreams;
import org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetTestUtil;
import org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetUtil;
import org.apache.hadoop.io.IOUtils;
import org.apache.hadoop.ipc.RemoteException;
import org.apache.hadoop.test.GenericTestUtils;
import org.apache.hadoop.util.DataChecksum;
import org.apache.hadoop.util.Time;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.Timeout;
/**
* This class tests the building blocks that are needed to
* support HDFS appends.
*/
public class TestFileAppend{
private static final long RANDOM_TEST_RUNTIME = 10000;
private static byte[] fileContents = null;
static final DataChecksum DEFAULT_CHECKSUM =
DataChecksum.newDataChecksum(DataChecksum.Type.CRC32C, 512);
//
// writes to file but does not close it
//
private void writeFile(FSDataOutputStream stm) throws IOException {
byte[] buffer = AppendTestUtil.initBuffer(AppendTestUtil.FILE_SIZE);
stm.write(buffer);
}
//
// verify that the data written to the full blocks are sane
//
private void checkFile(DistributedFileSystem 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, AppendTestUtil.FILE_SIZE);
if (locations.length < AppendTestUtil.NUM_BLOCKS) {
System.out.println("Number of blocks found " + locations.length);
done = false;
continue;
}
for (int idx = 0; idx < AppendTestUtil.NUM_BLOCKS; idx++) {
if (locations[idx].getHosts().length < repl) {
System.out.println("Block index " + idx + " not yet replciated.");
done = false;
break;
}
}
}
byte[] expected =
new byte[AppendTestUtil.NUM_BLOCKS * AppendTestUtil.BLOCK_SIZE];
System.arraycopy(fileContents, 0, expected, 0, expected.length);
// do a sanity check. Read the file
// do not check file status since the file is not yet closed.
AppendTestUtil.checkFullFile(fileSys, name,
AppendTestUtil.NUM_BLOCKS * AppendTestUtil.BLOCK_SIZE,
expected, "Read 1", false);
}
@Test
public void testBreakHardlinksIfNeeded() throws IOException {
Configuration conf = new HdfsConfiguration();
File builderBaseDir = new File(GenericTestUtils.getRandomizedTempPath());
MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf, builderBaseDir)
.build();
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 = AppendTestUtil.createFile(fs, file1, 1);
writeFile(stm);
stm.close();
// Get a handle to the datanode
DataNode[] dn = cluster.listDataNodes();
assertTrue(
dn.length == 1, "There should be only one datanode but found " + dn.length);
LocatedBlocks locations = client.getNamenode().getBlockLocations(
file1.toString(), 0, Long.MAX_VALUE);
List<LocatedBlock> blocks = locations.getLocatedBlocks();
final FsDatasetSpi<?> fsd = dn[0].getFSDataset();
//
// Create hard links for a few of the blocks
//
for (int i = 0; i < blocks.size(); i = i + 2) {
ExtendedBlock b = blocks.get(i).getBlock();
final File f = FsDatasetTestUtil.getBlockFile(
fsd, b.getBlockPoolId(), b.getLocalBlock());
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++) {
ExtendedBlock b = blocks.get(i).getBlock();
System.out.println("breakHardlinksIfNeeded detaching block " + b);
assertTrue(FsDatasetTestUtil.breakHardlinksIfNeeded(fsd, b),
"breakHardlinksIfNeeded(" + b + ") should have returned true");
}
// Since the blocks were already detached earlier, these calls should
// return false
for (int i = 0; i < blocks.size(); i++) {
ExtendedBlock b = blocks.get(i).getBlock();
System.out.println("breakHardlinksIfNeeded re-attempting to " +
"detach block " + b);
assertTrue(FsDatasetTestUtil.breakHardlinksIfNeeded(fsd, b),
"breakHardlinksIfNeeded(" + b + ") should have returned false");
}
} finally {
client.close();
fs.close();
cluster.shutdown();
}
}
/**
* Test a simple flush on a simple HDFS file.
* @throws IOException an exception might be thrown
*/
@Test
public void testSimpleFlush() throws IOException {
Configuration conf = new HdfsConfiguration();
fileContents = AppendTestUtil.initBuffer(AppendTestUtil.FILE_SIZE);
File builderBaseDir = new File(GenericTestUtils.getRandomizedTempPath());
MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf, builderBaseDir)
.build();
DistributedFileSystem fs = cluster.getFileSystem();
try {
// create a new file.
Path file1 = new Path("/simpleFlush.dat");
FSDataOutputStream stm = AppendTestUtil.createFile(fs, file1, 1);
System.out.println("Created file simpleFlush.dat");
// write to file
int mid = AppendTestUtil.FILE_SIZE /2;
stm.write(fileContents, 0, mid);
stm.hflush();
System.out.println("Wrote and Flushed first part of file.");
// write the remainder of the file
stm.write(fileContents, mid, AppendTestUtil.FILE_SIZE - mid);
System.out.println("Written second part of file");
stm.hflush();
stm.hflush();
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
AppendTestUtil.checkFullFile(fs, file1, AppendTestUtil.FILE_SIZE,
fileContents, "Read 2");
} 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.
* @throws IOException an exception might be thrown
*/
@Test
public void testComplexFlush() throws IOException {
Configuration conf = new HdfsConfiguration();
fileContents = AppendTestUtil.initBuffer(AppendTestUtil.FILE_SIZE);
File builderBaseDir = new File(GenericTestUtils.getRandomizedTempPath());
MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf, builderBaseDir)
.build();
DistributedFileSystem fs = cluster.getFileSystem();
try {
// create a new file.
Path file1 = new Path("/complexFlush.dat");
FSDataOutputStream stm = AppendTestUtil.createFile(fs, file1, 1);
System.out.println("Created file complexFlush.dat");
int start = 0;
for (start = 0; (start + 29) < AppendTestUtil.FILE_SIZE; ) {
stm.write(fileContents, start, 29);
stm.hflush();
start += 29;
}
stm.write(fileContents, start, AppendTestUtil.FILE_SIZE -start);
// need to make sure we completely write out all full blocks before
// the checkFile() call (see FSOutputSummer#flush)
stm.flush();
// verify that full blocks are sane
checkFile(fs, file1, 1);
stm.close();
// verify that entire file is good
AppendTestUtil.checkFullFile(fs, file1, AppendTestUtil.FILE_SIZE,
fileContents, "Read 2");
} 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();
}
}
/**
* FileNotFoundException is expected for appending to a non-exisiting file
*
* @throws FileNotFoundException as the result
*/
@Test
public void testFileNotFound() throws IOException {
assertThrows(FileNotFoundException.class, () -> {
Configuration conf = new HdfsConfiguration();
File builderBaseDir = new File(GenericTestUtils.getRandomizedTempPath());
MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf, builderBaseDir)
.build();
FileSystem fs = cluster.getFileSystem();
try {
Path file1 = new Path("/nonexistingfile.dat");
fs.append(file1);
} finally {
fs.close();
cluster.shutdown();
}
});
}
/** Test two consecutive appends on a file with a full block. */
@Test
public void testAppendTwice() throws Exception {
Configuration conf = new HdfsConfiguration();
File builderBaseDir = new File(GenericTestUtils.getRandomizedTempPath());
MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf, builderBaseDir)
.build();
final FileSystem fs1 = cluster.getFileSystem();
final FileSystem fs2 = AppendTestUtil.createHdfsWithDifferentUsername(conf);
try {
final Path p = new Path("/testAppendTwice/foo");
final int len = 1 << 16;
final byte[] fileContents = AppendTestUtil.initBuffer(len);
{
// create a new file with a full block.
FSDataOutputStream out = fs2.create(p, true, 4096, (short)1, len);
out.write(fileContents, 0, len);
out.close();
}
//1st append does not add any data so that the last block remains full
//and the last block in INodeFileUnderConstruction is a BlockInfo
//but does not have a BlockUnderConstructionFeature.
fs2.append(p);
//2nd append should get AlreadyBeingCreatedException
fs1.append(p);
fail();
} catch(RemoteException re) {
AppendTestUtil.LOG.info("Got an exception:", re);
assertEquals(AlreadyBeingCreatedException.class.getName(),
re.getClassName());
} finally {
fs2.close();
fs1.close();
cluster.shutdown();
}
}
/** Test two consecutive appends on a file with a full block. */
@Test
public void testAppend2Twice() throws Exception {
Configuration conf = new HdfsConfiguration();
File builderBaseDir = new File(GenericTestUtils.getRandomizedTempPath());
MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf, builderBaseDir)
.build();
final DistributedFileSystem fs1 = cluster.getFileSystem();
final FileSystem fs2 = AppendTestUtil.createHdfsWithDifferentUsername(conf);
try {
final Path p = new Path("/testAppendTwice/foo");
final int len = 1 << 16;
final byte[] fileContents = AppendTestUtil.initBuffer(len);
{
// create a new file with a full block.
FSDataOutputStream out = fs2.create(p, true, 4096, (short)1, len);
out.write(fileContents, 0, len);
out.close();
}
//1st append does not add any data so that the last block remains full
//and the last block in INodeFileUnderConstruction is a BlockInfo
//but does not have a BlockUnderConstructionFeature.
((DistributedFileSystem) fs2).append(p,
EnumSet.of(CreateFlag.APPEND, CreateFlag.NEW_BLOCK), 4096, null);
// 2nd append should get AlreadyBeingCreatedException
fs1.append(p);
fail();
} catch(RemoteException re) {
AppendTestUtil.LOG.info("Got an exception:", re);
assertEquals(AlreadyBeingCreatedException.class.getName(),
re.getClassName());
} finally {
fs2.close();
fs1.close();
cluster.shutdown();
}
}
@Test
public void testMultipleAppends() throws Exception {
final long startTime = Time.monotonicNow();
final Configuration conf = new HdfsConfiguration();
conf.setInt(
DFSConfigKeys.DFS_NAMENODE_FILE_CLOSE_NUM_COMMITTED_ALLOWED_KEY, 1);
conf.setBoolean(
HdfsClientConfigKeys.BlockWrite.ReplaceDatanodeOnFailure.ENABLE_KEY,
false);
File builderBaseDir = new File(GenericTestUtils.getRandomizedTempPath());
final MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf,
builderBaseDir).numDataNodes(4).build();
final DistributedFileSystem fs = cluster.getFileSystem();
try {
final Path p = new Path("/testMultipleAppend/foo");
final int blockSize = 1 << 16;
final byte[] data = AppendTestUtil.initBuffer(blockSize);
// create an empty file.
fs.create(p, true, 4096, (short)3, blockSize).close();
int fileLen = 0;
for(int i = 0;
i < 10 || Time.monotonicNow() - startTime < RANDOM_TEST_RUNTIME;
i++) {
int appendLen = ThreadLocalRandom.current().nextInt(100) + 1;
if (fileLen + appendLen > data.length) {
break;
}
AppendTestUtil.LOG.info(i + ") fileLen=" + fileLen
+ ", appendLen=" + appendLen);
final FSDataOutputStream out = fs.append(p);
out.write(data, fileLen, appendLen);
out.close();
fileLen += appendLen;
}
assertEquals(fileLen, fs.getFileStatus(p).getLen());
final byte[] actual = new byte[fileLen];
final FSDataInputStream in = fs.open(p);
in.readFully(actual);
in.close();
for(int i = 0; i < fileLen; i++) {
assertEquals(data[i], actual[i]);
}
} finally {
fs.close();
cluster.shutdown();
}
}
/** Tests appending after soft-limit expires. */
@Test
public void testAppendAfterSoftLimit()
throws IOException, InterruptedException {
Configuration conf = new HdfsConfiguration();
conf.setInt(DFSConfigKeys.DFS_REPLICATION_KEY, 1);
//Set small soft-limit for lease
final long softLimit = 1L;
final long hardLimit = 9999999L;
File builderBaseDir = new File(GenericTestUtils.getRandomizedTempPath());
MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf, builderBaseDir)
.numDataNodes(1).build();
cluster.setLeasePeriod(softLimit, hardLimit);
cluster.waitActive();
FileSystem fs = cluster.getFileSystem();
FileSystem fs2 = new DistributedFileSystem();
fs2.initialize(fs.getUri(), conf);
final Path testPath = new Path("/testAppendAfterSoftLimit");
final byte[] fileContents = AppendTestUtil.initBuffer(32);
// create a new file without closing
FSDataOutputStream out = fs.create(testPath);
out.write(fileContents);
//Wait for > soft-limit
Thread.sleep(250);
try {
FSDataOutputStream appendStream2 = fs2.append(testPath);
appendStream2.write(fileContents);
appendStream2.close();
assertEquals(fileContents.length, fs.getFileStatus(testPath).getLen());
} finally {
fs.close();
fs2.close();
cluster.shutdown();
}
}
/** Tests appending after soft-limit expires. */
@Test
public void testAppend2AfterSoftLimit() throws Exception {
Configuration conf = new HdfsConfiguration();
conf.setInt(DFSConfigKeys.DFS_REPLICATION_KEY, 1);
//Set small soft-limit for lease
final long softLimit = 1L;
final long hardLimit = 9999999L;
File builderBaseDir = new File(GenericTestUtils.getRandomizedTempPath());
MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf, builderBaseDir)
.numDataNodes(1).build();
cluster.setLeasePeriod(softLimit, hardLimit);
cluster.waitActive();
DistributedFileSystem fs = cluster.getFileSystem();
DistributedFileSystem fs2 = new DistributedFileSystem();
fs2.initialize(fs.getUri(), conf);
final Path testPath = new Path("/testAppendAfterSoftLimit");
final byte[] fileContents = AppendTestUtil.initBuffer(32);
// create a new file without closing
FSDataOutputStream out = fs.create(testPath);
out.write(fileContents);
//Wait for > soft-limit
Thread.sleep(250);
try {
FSDataOutputStream appendStream2 = fs2.append(testPath,
EnumSet.of(CreateFlag.APPEND, CreateFlag.NEW_BLOCK), 4096, null);
appendStream2.write(fileContents);
appendStream2.close();
assertEquals(fileContents.length, fs.getFileStatus(testPath).getLen());
// make sure we now have 1 block since the first writer was revoked
LocatedBlocks blks = fs.getClient().getLocatedBlocks(testPath.toString(),
0L);
assertEquals(1, blks.getLocatedBlocks().size());
for (LocatedBlock blk : blks.getLocatedBlocks()) {
assertEquals(fileContents.length, blk.getBlockSize());
}
} finally {
fs.close();
fs2.close();
cluster.shutdown();
}
}
/**
* Old replica of the block should not be accepted as valid for append/read
*/
@Test
public void testFailedAppendBlockRejection() throws Exception {
Configuration conf = new HdfsConfiguration();
conf.set("dfs.client.block.write.replace-datanode-on-failure.enable",
"false");
File builderBaseDir = new File(GenericTestUtils.getRandomizedTempPath());
MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf, builderBaseDir)
.numDataNodes(3).build();
DistributedFileSystem fs = null;
try {
fs = cluster.getFileSystem();
Path path = new Path("/test");
FSDataOutputStream out = fs.create(path);
out.writeBytes("hello\n");
out.close();
// stop one datanode
DataNodeProperties dnProp = cluster.stopDataNode(0);
String dnAddress = dnProp.datanode.getXferAddress().toString();
if (dnAddress.startsWith("/")) {
dnAddress = dnAddress.substring(1);
}
// append again to bump genstamps
for (int i = 0; i < 2; i++) {
out = fs.append(path);
out.writeBytes("helloagain\n");
out.close();
}
// re-open and make the block state as underconstruction
out = fs.append(path);
cluster.restartDataNode(dnProp, true);
// wait till the block report comes
Thread.sleep(2000);
// check the block locations, this should not contain restarted datanode
BlockLocation[] locations = fs.getFileBlockLocations(path, 0,
Long.MAX_VALUE);
String[] names = locations[0].getNames();
for (String node : names) {
if (node.equals(dnAddress)) {
fail("Failed append should not be present in latest block locations.");
}
}
out.close();
} finally {
IOUtils.closeStream(fs);
cluster.shutdown();
}
}
/**
* Old replica of the block should not be accepted as valid for append/read
*/
@Test
public void testMultiAppend2() throws Exception {
Configuration conf = new HdfsConfiguration();
conf.set("dfs.client.block.write.replace-datanode-on-failure.enable",
"false");
File builderBaseDir = new File(GenericTestUtils.getRandomizedTempPath());
MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf, builderBaseDir)
.numDataNodes(3).build();
DistributedFileSystem fs = null;
final String hello = "hello\n";
try {
fs = cluster.getFileSystem();
Path path = new Path("/test");
FSDataOutputStream out = fs.create(path);
out.writeBytes(hello);
out.close();
// stop one datanode
DataNodeProperties dnProp = cluster.stopDataNode(0);
String dnAddress = dnProp.datanode.getXferAddress().toString();
if (dnAddress.startsWith("/")) {
dnAddress = dnAddress.substring(1);
}
// append again to bump genstamps
for (int i = 0; i < 2; i++) {
out = fs.append(path,
EnumSet.of(CreateFlag.APPEND, CreateFlag.NEW_BLOCK), 4096, null);
out.writeBytes(hello);
out.close();
}
// re-open and make the block state as underconstruction
out = fs.append(path, EnumSet.of(CreateFlag.APPEND, CreateFlag.NEW_BLOCK),
4096, null);
cluster.restartDataNode(dnProp, true);
// wait till the block report comes
Thread.sleep(2000);
out.writeBytes(hello);
out.close();
// check the block locations
LocatedBlocks blocks = fs.getClient().getLocatedBlocks(path.toString(), 0L);
// since we append the file 3 time, we should be 4 blocks
assertEquals(4, blocks.getLocatedBlocks().size());
for (LocatedBlock block : blocks.getLocatedBlocks()) {
assertEquals(hello.length(), block.getBlockSize());
}
StringBuilder sb = new StringBuilder();
for (int i = 0; i < 4; i++) {
sb.append(hello);
}
final byte[] content = sb.toString().getBytes();
AppendTestUtil.checkFullFile(fs, path, content.length, content,
"Read /test");
// restart namenode to make sure the editlog can be properly applied
cluster.restartNameNode(true);
cluster.waitActive();
AppendTestUtil.checkFullFile(fs, path, content.length, content,
"Read /test");
blocks = fs.getClient().getLocatedBlocks(path.toString(), 0L);
// since we append the file 3 time, we should be 4 blocks
assertEquals(4, blocks.getLocatedBlocks().size());
for (LocatedBlock block : blocks.getLocatedBlocks()) {
assertEquals(hello.length(), block.getBlockSize());
}
} finally {
IOUtils.closeStream(fs);
cluster.shutdown();
}
}
@Test
@Timeout(value = 10)
public void testAppendCorruptedBlock() throws Exception {
Configuration conf = new HdfsConfiguration();
conf.setInt(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, 1024);
conf.setInt(DFSConfigKeys.DFS_REPLICATION_KEY, 1);
File builderBaseDir = new File(GenericTestUtils.getRandomizedTempPath());
MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf, builderBaseDir)
.numDataNodes(1).build();
try {
DistributedFileSystem fs = cluster.getFileSystem();
Path fileName = new Path("/appendCorruptBlock");
DFSTestUtil.createFile(fs, fileName, 512, (short) 1, 0);
DFSTestUtil.waitReplication(fs, fileName, (short) 1);
assertTrue(fs.exists(fileName), "File not created");
ExtendedBlock block = DFSTestUtil.getFirstBlock(fs, fileName);
cluster.corruptBlockOnDataNodes(block);
DFSTestUtil.appendFile(fs, fileName, "appendCorruptBlock");
} finally {
cluster.shutdown();
}
}
@Test
@Timeout(value = 10)
public void testConcurrentAppendRead()
throws IOException, TimeoutException, InterruptedException {
// Create a finalized replica and append to it
// Read block data and checksum. Verify checksum.
Configuration conf = new HdfsConfiguration();
conf.setInt(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, 1024);
conf.setInt(DFSConfigKeys.DFS_REPLICATION_KEY, 1);
File builderBaseDir = new File(GenericTestUtils.getRandomizedTempPath());
MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf, builderBaseDir)
.build();
try {
cluster.waitActive();
DataNode dn = cluster.getDataNodes().get(0);
FsDatasetSpi<?> dataSet = DataNodeTestUtils.getFSDataset(dn);
// create a file with 1 byte of data.
long initialFileLength = 1;
DistributedFileSystem fs = cluster.getFileSystem();
Path fileName = new Path("/appendCorruptBlock");
DFSTestUtil.createFile(fs, fileName, initialFileLength, (short) 1, 0);
DFSTestUtil.waitReplication(fs, fileName, (short) 1);
assertTrue(fs.exists(fileName), "File not created");
// Call FsDatasetImpl#append to append the block file,
// which converts it to a rbw replica.
ExtendedBlock block = DFSTestUtil.getFirstBlock(fs, fileName);
long newGS = block.getGenerationStamp() + 1;
ReplicaHandler replicaHandler =
dataSet.append(block, newGS, initialFileLength);
// write data to block file
ReplicaBeingWritten rbw =
(ReplicaBeingWritten)replicaHandler.getReplica();
ReplicaOutputStreams
outputStreams = rbw.createStreams(false, DEFAULT_CHECKSUM);
OutputStream dataOutput = outputStreams.getDataOut();
byte[] appendBytes = new byte[1];
dataOutput.write(appendBytes, 0, 1);
dataOutput.flush();
dataOutput.close();
// update checksum file
final int smallBufferSize = DFSUtilClient.getSmallBufferSize(conf);
FsDatasetUtil.computeChecksum(rbw.getMetaFile(), rbw.getMetaFile(),
rbw.getBlockFile(), smallBufferSize, conf);
// read the block
// the DataNode BlockSender should read from the rbw replica's in-memory
// checksum, rather than on-disk checksum. Otherwise it will see a
// checksum mismatch error.
final byte[] readBlock = DFSTestUtil.readFileBuffer(fs, fileName);
assertEquals(1, readBlock.length, "should have read only one byte!");
} finally {
cluster.shutdown();
}
}
}