HDFS-9308. Add truncateMeta() and deleteMeta() to MiniDFSCluster. (Tony Wu via lei)

(cherry picked from commit 8e05dbf2bd)

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -814,6 +814,8 @@ Release 2.8.0 - UNRELEASED
 
     HDFS-9312. Fix TestReplication to be FsDataset-agnostic. (lei)
 
+    HDFS-9308. Add truncateMeta() and deleteMeta() to MiniDFSCluster. (Tony Wu via lei)
+
   BUG FIXES
 
     HDFS-8091: ACLStatus and XAttributes should be presented to

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/MiniDFSCluster.java

@@ -2002,6 +2002,28 @@ public void corruptMeta(int i, ExtendedBlock blk) throws IOException {
     getMaterializedReplica(i, blk).corruptMeta();
   }
 
+  /**
+   * Corrupt the metadata of a block by deleting it.
+   * @param i index of the datanode
+   * @param blk name of the block.
+   */
+  public void deleteMeta(int i, ExtendedBlock blk)
+      throws IOException {
+    getMaterializedReplica(i, blk).deleteMeta();
+  }
+
+  /**
+   * Corrupt the metadata of a block by truncating it to a new size.
+   * @param i index of the datanode.
+   * @param blk name of the block.
+   * @param newSize the new size of the metadata file.
+   * @throws IOException if any I/O errors.
+   */
+  public void truncateMeta(int i, ExtendedBlock blk, int newSize)
+      throws IOException {
+    getMaterializedReplica(i, blk).truncateMeta(newSize);
+  }
+
   public boolean changeGenStampOfBlock(int dnIndex, ExtendedBlock blk,
       long newGenStamp) throws IOException {
     File blockFile = getBlockFile(dnIndex, blk);

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestCrcCorruption.java

@@ -22,11 +22,8 @@
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
-import java.io.File;
 import java.io.IOException;
-import java.io.RandomAccessFile;
+import java.util.List;
-import java.nio.ByteBuffer;
-import java.nio.channels.FileChannel;
 import java.util.Random;
 
 import org.apache.hadoop.conf.Configuration;
@@ -35,12 +32,15 @@
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hdfs.client.HdfsClientConfigKeys;
-import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
+import org.apache.hadoop.hdfs.server.datanode.DataNode;
+import org.apache.hadoop.hdfs.server.datanode.FinalizedReplica;
 import org.apache.hadoop.io.IOUtils;
 import org.junit.Before;
 import org.junit.Test;
 import org.mockito.Mockito;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * A JUnit test for corrupted file handling.
@@ -70,6 +70,8 @@
  *     replica was created from the non-corrupted replica.
  */
 public class TestCrcCorruption {
+  public static final Logger LOG =
+      LoggerFactory.getLogger(TestCrcCorruption.class);
 
   private DFSClientFaultInjector faultInjector;
 
@@ -167,90 +169,26 @@ private void thistest(Configuration conf, DFSTestUtil util) throws Exception {
       // file disallows this Datanode to send data to another datanode.
       // However, a client is alowed access to this block.
       //
-      File storageDir = cluster.getInstanceStorageDir(0, 1);
+      final int dnIdx = 0;
-      String bpid = cluster.getNamesystem().getBlockPoolId();
+      final DataNode dn = cluster.getDataNodes().get(dnIdx);
-      File data_dir = MiniDFSCluster.getFinalizedDir(storageDir, bpid);
+      final String bpid = cluster.getNamesystem().getBlockPoolId();
-      assertTrue("data directory does not exist", data_dir.exists());
+      List<FinalizedReplica> replicas =
-      File[] blocks = data_dir.listFiles();
+          dn.getFSDataset().getFinalizedBlocks(bpid);
-      assertTrue("Blocks do not exist in data-dir", (blocks != null) && (blocks.length > 0));
+      assertTrue("Replicas do not exist", !replicas.isEmpty());
-      int num = 0;
-      for (int idx = 0; idx < blocks.length; idx++) {
-        if (blocks[idx].getName().startsWith(Block.BLOCK_FILE_PREFIX) &&
-            blocks[idx].getName().endsWith(".meta")) {
-          num++;
-          if (num % 3 == 0) {
-            //
-            // remove .meta file
-            //
-            System.out.println("Deliberately removing file " + blocks[idx].getName());
-            assertTrue("Cannot remove file.", blocks[idx].delete());
-          } else if (num % 3 == 1) {
-            //
-            // shorten .meta file
-            //
-            RandomAccessFile file = new RandomAccessFile(blocks[idx], "rw");
-            FileChannel channel = file.getChannel();
-            int newsize = random.nextInt((int)channel.size()/2);
-            System.out.println("Deliberately truncating file " + 
-                               blocks[idx].getName() + 
-                               " to size " + newsize + " bytes.");
-            channel.truncate(newsize);
-            file.close();
-          } else {
-            //
-            // corrupt a few bytes of the metafile
-            //
-            RandomAccessFile file = new RandomAccessFile(blocks[idx], "rw");
-            FileChannel channel = file.getChannel();
-            long position = 0;
-            //
-            // The very first time, corrupt the meta header at offset 0
-            //
-            if (num != 2) {
-              position = (long)random.nextInt((int)channel.size());
-            }
-            int length = random.nextInt((int)(channel.size() - position + 1));
-            byte[] buffer = new byte[length];
-            random.nextBytes(buffer);
-            channel.write(ByteBuffer.wrap(buffer), position);
-            System.out.println("Deliberately corrupting file " + 
-                               blocks[idx].getName() + 
-                               " at offset " + position +
-                               " length " + length);
-            file.close();
-          }
-        }
-      }
-      
-      //
-      // Now deliberately corrupt all meta blocks from the second
-      // directory of the first datanode
-      //
-      storageDir = cluster.getInstanceStorageDir(0, 1);
-      data_dir = MiniDFSCluster.getFinalizedDir(storageDir, bpid);
-      assertTrue("data directory does not exist", data_dir.exists());
-      blocks = data_dir.listFiles();
-      assertTrue("Blocks do not exist in data-dir", (blocks != null) && (blocks.length > 0));
 
-      int count = 0;
+      for (int idx = 0; idx < replicas.size(); idx++) {
-      File previous = null;
+        FinalizedReplica replica = replicas.get(idx);
-      for (int idx = 0; idx < blocks.length; idx++) {
+        ExtendedBlock eb = new ExtendedBlock(bpid, replica);
-        if (blocks[idx].getName().startsWith("blk_") &&
+        if (idx % 3 == 0) {
-            blocks[idx].getName().endsWith(".meta")) {
+          LOG.info("Deliberately removing meta for block " + eb);
-          //
+          cluster.deleteMeta(dnIdx, eb);
-          // Move the previous metafile into the current one.
+        } else if (idx % 3 == 1) {
-          //
+          final int newSize = 2;  // bytes
-          count++;
+          LOG.info("Deliberately truncating meta file for block " +
-          if (count % 2 == 0) {
+              eb + " to size " +  newSize + " bytes.");
-            System.out.println("Deliberately insertimg bad crc into files " +
+          cluster.truncateMeta(dnIdx, eb, newSize);
-                                blocks[idx].getName() + " " + previous.getName());
+        } else {
-            assertTrue("Cannot remove file.", blocks[idx].delete());
+          cluster.corruptMeta(dnIdx, eb);
-            assertTrue("Cannot corrupt meta file.", previous.renameTo(blocks[idx]));
-            assertTrue("Cannot recreate empty meta file.", previous.createNewFile());
-            previous = null;
-          } else {
-            previous = blocks[idx];
-          }
         }
       }
 
@@ -260,7 +198,7 @@ private void thistest(Configuration conf, DFSTestUtil util) throws Exception {
       //
       assertTrue("Corrupted replicas not handled properly.",
                  util.checkFiles(fs, "/srcdat"));
-      System.out.println("All File still have a valid replica");
+      LOG.info("All File still have a valid replica");
 
       //
       // set replication factor back to 1. This causes only one replica of
@@ -273,7 +211,7 @@ private void thistest(Configuration conf, DFSTestUtil util) throws Exception {
       //System.out.println("All Files done with removing replicas");
       //assertTrue("Excess replicas deleted. Corrupted replicas found.",
       //           util.checkFiles(fs, "/srcdat"));
-      System.out.println("The excess-corrupted-replica test is disabled " +
+      LOG.info("The excess-corrupted-replica test is disabled " +
                          " pending HADOOP-1557");
 
       util.cleanup(fs, "/srcdat");

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestLeaseRecovery.java

@@ -20,9 +20,7 @@
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
-import java.io.File;
 import java.io.IOException;
-import java.io.RandomAccessFile;
 import java.util.EnumSet;
 
 import org.apache.hadoop.conf.Configuration;
@@ -32,7 +30,6 @@
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hdfs.MiniDFSCluster.DataNodeProperties;
 import org.apache.hadoop.hdfs.protocol.Block;
-import org.apache.hadoop.hdfs.protocol.BlockLocalPathInfo;
 import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
 import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
@@ -178,8 +175,9 @@ public void testBlockRecoveryWithLessMetafile() throws Exception {
     Path file = new Path("/testRecoveryFile");
     DistributedFileSystem dfs = cluster.getFileSystem();
     FSDataOutputStream out = dfs.create(file);
+    final int FILE_SIZE = 2 * 1024 * 1024;
     int count = 0;
-    while (count < 2 * 1024 * 1024) {
+    while (count < FILE_SIZE) {
       out.writeBytes("Data");
       count += 4;
     }
@@ -190,15 +188,23 @@ public void testBlockRecoveryWithLessMetafile() throws Exception {
     LocatedBlocks locations = cluster.getNameNodeRpc().getBlockLocations(
         file.toString(), 0, count);
     ExtendedBlock block = locations.get(0).getBlock();
-    DataNode dn = cluster.getDataNodes().get(0);
-    BlockLocalPathInfo localPathInfo = dn.getBlockLocalPathInfo(block, null);
-    File metafile = new File(localPathInfo.getMetaPath());
-    assertTrue(metafile.exists());
 
-    // reduce the block meta file size
+    // Calculate meta file size
-    RandomAccessFile raf = new RandomAccessFile(metafile, "rw");
+    // From DataNode.java, checksum size is given by:
-    raf.setLength(metafile.length() - 20);
+    // (length of data + BYTE_PER_CHECKSUM - 1)/BYTES_PER_CHECKSUM *
-    raf.close();
+    // CHECKSUM_SIZE
+    final int CHECKSUM_SIZE = 4; // CRC32 & CRC32C
+    final int bytesPerChecksum = conf.getInt(
+        DFSConfigKeys.DFS_BYTES_PER_CHECKSUM_KEY,
+        DFSConfigKeys.DFS_BYTES_PER_CHECKSUM_DEFAULT);
+    final int metaFileSize =
+        (FILE_SIZE + bytesPerChecksum - 1) / bytesPerChecksum * CHECKSUM_SIZE +
+        8; // meta file header is 8 bytes
+    final int newMetaFileSize = metaFileSize - CHECKSUM_SIZE;
+
+    // Corrupt the block meta file by dropping checksum for bytesPerChecksum
+    // bytes. Lease recovery is expected to recover the uncorrupted file length.
+    cluster.truncateMeta(0, block, newMetaFileSize);
 
     // restart DN to make replica to RWR
     DataNodeProperties dnProp = cluster.stopDataNode(0);
@@ -213,6 +219,11 @@ public void testBlockRecoveryWithLessMetafile() throws Exception {
     }
     assertTrue("File should be closed", newdfs.recoverLease(file));
 
+    // Verify file length after lease recovery. The new file length should not
+    // include the bytes with corrupted checksum.
+    final long expectedNewFileLen = FILE_SIZE - bytesPerChecksum;
+    final long newFileLen = newdfs.getFileStatus(file).getLen();
+    assertEquals(newFileLen, expectedNewFileLen);
   }
 
   /**