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HDFS-15725. Lease Recovery never completes for a committed block which the DNs never finalize. Contributed by Stephen O'Donnell

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This commit is contained in:
S O'Donnell 2020-12-11 18:45:58 +00:00
parent 6de1a8eb67
commit 9ed737001c
2 changed files with 189 additions and 28 deletions
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18
hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java
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@ -3711,17 +3711,6 @@ boolean internalReleaseLease(Lease lease, String src, INodesInPath iip,
" internalReleaseLease: Committed blocks are minimally" +
" replicated, lease removed, file" + src + " closed.");
return true; // closed!
} else if (penultimateBlockMinStorage && lastBlock.getNumBytes() == 0) {
// HDFS-14498 - this is a file with a final block of zero bytes and was
// likely left in this state by a client which exited unexpectedly
pendingFile.removeLastBlock(lastBlock);
finalizeINodeFileUnderConstruction(src, pendingFile,
iip.getLatestSnapshotId(), false);
NameNode.stateChangeLog.warn("BLOCK*" +
" internalReleaseLease: Committed last block is zero bytes with" +
" insufficient replicas. Final block removed, lease removed, file "
+ src + " closed.");
return true;
}
// Cannot close file right now, since some blocks
// are not yet minimally replicated.
@ -3729,10 +3718,13 @@ boolean internalReleaseLease(Lease lease, String src, INodesInPath iip,
// if there are no valid replicas on data-nodes.
String message = "DIR* NameSystem.internalReleaseLease: " +
"Failed to release lease for file " + src +
". Committed blocks are waiting to be minimally replicated." +
" Try again later.";
". Committed blocks are waiting to be minimally replicated.";
NameNode.stateChangeLog.warn(message);
if (!penultimateBlockMinStorage) {
throw new AlreadyBeingCreatedException(message);
}
// Intentionally fall through to UNDER_RECOVERY so BLOCK_RECOVERY is
// attempted
case UNDER_CONSTRUCTION:
case UNDER_RECOVERY:
BlockUnderConstructionFeature uc =

195
hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestLeaseRecovery.java
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@ -17,36 +17,46 @@
*/
package org.apache.hadoop.hdfs;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;
import java.io.IOException;
import java.util.EnumSet;
import java.util.function.Supplier;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.crypto.CryptoProtocolVersion;
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.Path;
import org.apache.hadoop.fs.permission.FsPermission;
import org.apache.hadoop.hdfs.MiniDFSCluster.DataNodeProperties;
import org.apache.hadoop.hdfs.protocol.Block;
import org.apache.hadoop.hdfs.protocol.BlockType;
import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
import org.apache.hadoop.hdfs.protocol.HdfsConstants;
import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
import org.apache.hadoop.hdfs.protocol.LocatedBlock;
import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
import org.apache.hadoop.hdfs.server.blockmanagement.BlockManager;
import org.apache.hadoop.hdfs.server.blockmanagement.BlockUnderConstructionFeature;
import org.apache.hadoop.hdfs.server.datanode.DataNode;
import org.apache.hadoop.hdfs.server.datanode.DataNodeTestUtils;
import org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.TestInterDatanodeProtocol;
import org.apache.hadoop.hdfs.server.namenode.INodeFile;
import org.apache.hadoop.hdfs.server.namenode.LeaseManager;
import org.apache.hadoop.hdfs.server.namenode.NameNodeAdapter;
import org.apache.hadoop.io.EnumSetWritable;
import org.apache.hadoop.ipc.RemoteException;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.test.GenericTestUtils;
import org.apache.hadoop.util.DataChecksum;
import org.junit.After;
import org.junit.Test;
@ -351,7 +361,13 @@ public void testLeaseRecoveryEmptyCommittedLastBlock() throws Exception {
String file = "/test/f1";
Path filePath = new Path(file);
createCommittedNotCompleteFile(client, file);
createCommittedNotCompleteFile(client, file, null, 1);
INodeFile inode = cluster.getNamesystem().getFSDirectory()
.getINode(filePath.toString()).asFile();
assertTrue(inode.isUnderConstruction());
assertEquals(1, inode.numBlocks());
assertNotNull(inode.getLastBlock());
// Ensure a different client cannot append the file
try {
@ -361,9 +377,18 @@ public void testLeaseRecoveryEmptyCommittedLastBlock() throws Exception {
assertTrue(e.getMessage().contains("file lease is currently owned"));
}
// Ensure the lease can be recovered on the first try
boolean recovered = client.recoverLease(file);
assertEquals(true, recovered);
// Lease will not be recovered on the first try
assertEquals(false, client.recoverLease(file));
for (int i=0; i < 10 && !client.recoverLease(file); i++) {
Thread.sleep(1000);
}
assertTrue(client.recoverLease(file));
inode = cluster.getNamesystem().getFSDirectory()
.getINode(filePath.toString()).asFile();
assertTrue(!inode.isUnderConstruction());
assertEquals(0, inode.numBlocks());
assertNull(inode.getLastBlock());
// Ensure the recovered file can now be written
FSDataOutputStream append = dfs.append(filePath);
@ -395,7 +420,7 @@ public void testLeaseManagerRecoversEmptyCommittedLastBlock()
new DFSClient(cluster.getNameNode().getServiceRpcAddress(), conf);
String file = "/test/f1";
createCommittedNotCompleteFile(client, file);
createCommittedNotCompleteFile(client, file, null, 1);
waitLeaseRecovery(cluster);
GenericTestUtils.waitFor(() -> {
@ -415,23 +440,167 @@ public void testLeaseManagerRecoversEmptyCommittedLastBlock()
}
}
private void createCommittedNotCompleteFile(DFSClient client, String file)
throws IOException {
@Test
public void testAbortedRecovery() throws Exception {
Configuration conf = new Configuration();
DFSClient client = null;
try {
cluster = new MiniDFSCluster.Builder(conf).numDataNodes(1).build();
client =
new DFSClient(cluster.getNameNode().getServiceRpcAddress(), conf);
final String file = "/test/f1";
HdfsFileStatus stat = client.getNamenode()
.create(file, new FsPermission("777"), "test client",
.create(file, new FsPermission("777"), client.clientName,
new EnumSetWritable<CreateFlag>(EnumSet.of(CreateFlag.CREATE)),
true, (short) 1, 1024 * 1024 * 128L,
new CryptoProtocolVersion[0], null, null);
assertNotNull(NameNodeAdapter.getLeaseHolderForPath(
cluster.getNameNode(), file));
// Add a block to the file
ExtendedBlock block = client.getNamenode().addBlock(
file, client.clientName, null, new DatanodeInfo[0], stat.getFileId(),
new String[0], null).getBlock();
// update the pipeline to get a new genstamp.
ExtendedBlock updatedBlock = client.getNamenode()
.updateBlockForPipeline(block, client.clientName)
.getBlock();
// fake that some data was maybe written. commit block sync will
// reconcile.
updatedBlock.setNumBytes(1234);
// get the stored block and make it look like the DN sent a RBW IBR.
BlockManager bm = cluster.getNamesystem().getBlockManager();
BlockInfo storedBlock = bm.getStoredBlock(block.getLocalBlock());
BlockUnderConstructionFeature uc =
storedBlock.getUnderConstructionFeature();
uc.setExpectedLocations(updatedBlock.getLocalBlock(),
uc.getExpectedStorageLocations(), BlockType.CONTIGUOUS);
// complete the file w/o updatePipeline to simulate client failure.
client.getNamenode().complete(file, client.clientName, block,
stat.getFileId());
assertNotNull(NameNodeAdapter.getLeaseHolderForPath(
cluster.getNameNode(), file));
cluster.setLeasePeriod(LEASE_PERIOD, LEASE_PERIOD);
GenericTestUtils.waitFor(new Supplier<Boolean>() {
@Override
public Boolean get() {
String holder = NameNodeAdapter
.getLeaseHolderForPath(cluster.getNameNode(), file);
return holder == null;
}
}, 100, 20000);
// nothing was actually written so the block should be dropped.
assertTrue(storedBlock.isDeleted());
} finally {
if (cluster != null) {
cluster.shutdown();
cluster = null;
}
if (client != null) {
client.close();
}
}
}
@Test
public void testLeaseManagerRecoversCommittedLastBlockWithContent()
throws Exception {
Configuration conf = new Configuration();
DFSClient client = null;
try {
cluster = new MiniDFSCluster.Builder(conf).numDataNodes(3).build();
client =
new DFSClient(cluster.getNameNode().getServiceRpcAddress(), conf);
String file = "/test/f2";
byte[] bytesToWrite = new byte[1];
bytesToWrite[0] = 123;
createCommittedNotCompleteFile(client, file, bytesToWrite, 3);
waitLeaseRecovery(cluster);
DistributedFileSystem hdfs = cluster.getFileSystem();
// Now the least has been recovered, attempt to append the file and then
// ensure the earlier written and newly written data can be read back.
FSDataOutputStream op = null;
try {
op = hdfs.append(new Path(file));
op.write(23);
} finally {
if (op != null) {
op.close();
}
}
FSDataInputStream stream = null;
try {
stream = cluster.getFileSystem().open(new Path(file));
assertEquals(123, stream.readByte());
assertEquals(23, stream.readByte());
} finally {
stream.close();
}
// Finally check there are no leases for the file and hence the file is
// closed.
GenericTestUtils.waitFor(() -> {
String holder = NameNodeAdapter
.getLeaseHolderForPath(cluster.getNameNode(), file);
return holder == null;
}, 100, 10000);
} finally {
if (cluster != null) {
cluster.shutdown();
cluster = null;
}
if (client != null) {
client.close();
}
}
}
private void createCommittedNotCompleteFile(DFSClient client, String file,
byte[] bytesToWrite, int repFactor) throws IOException {
HdfsFileStatus stat = client.getNamenode()
.create(file, new FsPermission("777"), client.clientName,
new EnumSetWritable<CreateFlag>(EnumSet.of(CreateFlag.CREATE)),
true, (short) repFactor, 1024 * 1024 * 128L,
new CryptoProtocolVersion[0], null, null);
// Add a block to the file
LocatedBlock blk = client.getNamenode()
.addBlock(file, "test client", null,
.addBlock(file, client.clientName, null,
new DatanodeInfo[0], stat.getFileId(), new String[0], null);
// Without writing anything to the file, or setting up the DN pipeline
// attempt to close the file. This will fail (return false) as the NN will
ExtendedBlock finalBlock = blk.getBlock();
if (bytesToWrite != null) {
// Here we create a output stream and then abort it so the block gets
// created on the datanode, but we never send the message to tell the DN
// to complete the block. This simulates the client crashing after it
// wrote the data, but before the file gets closed.
DFSOutputStream s = new DFSOutputStream(client, file, stat,
EnumSet.of(CreateFlag.CREATE), null,
DataChecksum.newDataChecksum(DataChecksum.Type.CRC32C, 512),
null, true);
s.start();
s.write(bytesToWrite);
s.hflush();
finalBlock = s.getBlock();
s.abort();
}
// Attempt to close the file. This will fail (return false) as the NN will
// be expecting the registered block to be reported from the DNs via IBR,
// but that will never happen, as the pipeline was never established
// but that will never happen, as we either did not write it, or we aborted
// the stream preventing the "close block" message to be sent to the DN.
boolean closed = client.getNamenode().complete(
file, "test client", blk.getBlock(), stat.getFileId());
file, client.clientName, finalBlock, stat.getFileId());
assertEquals(false, closed);
}