HDFS-2824. Fix failover when prior NN died just after creating an edit log segment. Contributed by Aaron T. Myers.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/HDFS-1623@1238069 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.HDFS-1623.txt

@@ -139,3 +139,5 @@ HDFS-2805. Add a test for a federated cluster with HA NNs. (Brandon Li via jiten
 HDFS-2841. HAAdmin does not work if security is enabled. (atm)
 
 HDFS-2691. Fixes for pipeline recovery in an HA cluster: report RBW replicas immediately upon pipeline creation. (todd)
+
+HDFS-2824. Fix failover when prior NN died just after creating an edit log segment. (atm via todd)

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/EditLogFileInputStream.java

@@ -168,11 +168,11 @@ class EditLogFileInputStream extends EditLogInputStream {
     try {
       in = new EditLogFileInputStream(file);
     } catch (LogHeaderCorruptException corrupt) {
-      // If it's missing its header, this is equivalent to no transactions
+      // If the header is malformed or the wrong value, this indicates a corruption
       FSImage.LOG.warn("Log at " + file + " has no valid header",
           corrupt);
-      return new FSEditLogLoader.EditLogValidation(0, HdfsConstants.INVALID_TXID, 
+      return new FSEditLogLoader.EditLogValidation(0,
-                                                   HdfsConstants.INVALID_TXID);
+          HdfsConstants.INVALID_TXID, HdfsConstants.INVALID_TXID, true);
     }
     
     try {

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/EditLogFileOutputStream.java

@@ -18,6 +18,7 @@
 
 package org.apache.hadoop.hdfs.server.namenode;
 
+import java.io.DataOutputStream;
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
@@ -27,6 +28,7 @@ import java.nio.channels.FileChannel;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
 import org.apache.hadoop.io.IOUtils;
 
@@ -36,7 +38,8 @@ import com.google.common.annotations.VisibleForTesting;
  * An implementation of the abstract class {@link EditLogOutputStream}, which
  * stores edits in a local file.
  */
-class EditLogFileOutputStream extends EditLogOutputStream {
+@InterfaceAudience.Private
+public class EditLogFileOutputStream extends EditLogOutputStream {
   private static Log LOG = LogFactory.getLog(EditLogFileOutputStream.class);
 
   private File file;
@@ -96,11 +99,23 @@ class EditLogFileOutputStream extends EditLogOutputStream {
   public void create() throws IOException {
     fc.truncate(0);
     fc.position(0);
-    doubleBuf.getCurrentBuf().writeInt(HdfsConstants.LAYOUT_VERSION);
+    writeHeader(doubleBuf.getCurrentBuf());
     setReadyToFlush();
     flush();
   }
 
+  /**
+   * Write header information for this EditLogFileOutputStream to the provided
+   * DataOutputSream.
+   * 
+   * @param out the output stream to write the header to.
+   * @throws IOException in the event of error writing to the stream.
+   */
+  @VisibleForTesting
+  public static void writeHeader(DataOutputStream out) throws IOException {
+    out.writeInt(HdfsConstants.LAYOUT_VERSION);
+  }
+
   @Override
   public void close() throws IOException {
     if (fp == null) {

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogLoader.java

@@ -605,19 +605,21 @@ public class FSEditLogLoader {
       FSImage.LOG.debug("Caught exception after reading " + numValid +
           " ops from " + in + " while determining its valid length.", t);
     }
-    return new EditLogValidation(lastPos, firstTxId, lastTxId);
+    return new EditLogValidation(lastPos, firstTxId, lastTxId, false);
   }
   
   static class EditLogValidation {
-    private long validLength;
+    private final long validLength;
-    private long startTxId;
+    private final long startTxId;
-    private long endTxId;
+    private final long endTxId;
+    private final boolean corruptionDetected;
      
-    EditLogValidation(long validLength, 
+    EditLogValidation(long validLength, long startTxId, long endTxId,
-                      long startTxId, long endTxId) {
+        boolean corruptionDetected) {
       this.validLength = validLength;
       this.startTxId = startTxId;
       this.endTxId = endTxId;
+      this.corruptionDetected = corruptionDetected;
     }
     
     long getValidLength() { return validLength; }
@@ -633,6 +635,8 @@ public class FSEditLogLoader {
       }
       return (endTxId - startTxId) + 1;
     }
+    
+    boolean hasCorruptHeader() { return corruptionDetected; }
   }
 
   /**

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FileJournalManager.java

@@ -31,7 +31,6 @@ import java.util.regex.Pattern;
 import org.apache.hadoop.fs.FileUtil;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
 import org.apache.hadoop.hdfs.server.common.Storage.StorageDirectory;
-import org.apache.hadoop.hdfs.server.namenode.JournalManager.CorruptionException;
 import org.apache.hadoop.hdfs.server.namenode.NNStorageRetentionManager.StoragePurger;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogLoader.EditLogValidation;
 import org.apache.hadoop.hdfs.server.namenode.NNStorage.NameNodeFile;
@@ -61,7 +60,6 @@ class FileJournalManager implements JournalManager {
     NameNodeFile.EDITS_INPROGRESS.getName() + "_(\\d+)");
 
   private File currentInProgress = null;
-  private long maxSeenTransaction = 0L;
 
   @VisibleForTesting
   StoragePurger purger
@@ -143,7 +141,7 @@ class FileJournalManager implements JournalManager {
         allLogFiles.size());
 
     for (EditLogFile elf : allLogFiles) {
-      if (elf.isCorrupt() || elf.isInProgress()) continue;
+      if (elf.hasCorruptHeader() || elf.isInProgress()) continue;
       if (elf.getFirstTxId() >= firstTxId) {
         ret.add(new RemoteEditLog(elf.firstTxId, elf.lastTxId));
       } else if ((firstTxId > elf.getFirstTxId()) &&
@@ -244,7 +242,7 @@ class FileJournalManager implements JournalManager {
           elf.validateLog();
         } 
 
-        if (elf.isCorrupt()) {
+        if (elf.hasCorruptHeader()) {
           break;
         }
         numTxns += elf.getLastTxId() + 1 - fromTxId;
@@ -281,22 +279,38 @@ class FileJournalManager implements JournalManager {
     File currentDir = sd.getCurrentDir();
     LOG.info("Recovering unfinalized segments in " + currentDir);
     List<EditLogFile> allLogFiles = matchEditLogs(currentDir.listFiles());
-    
-    // make sure journal is aware of max seen transaction before moving corrupt 
-    // files aside
-    findMaxTransaction(true);
 
     for (EditLogFile elf : allLogFiles) {
       if (elf.getFile().equals(currentInProgress)) {
         continue;
       }
       if (elf.isInProgress()) {
-        elf.validateLog();
+        // If the file is zero-length, we likely just crashed after opening the
-
+        // file, but before writing anything to it. Safe to delete it.
-        if (elf.isCorrupt()) {
+        if (elf.getFile().length() == 0) {
-          elf.moveAsideCorruptFile();
+          LOG.info("Deleting zero-length edit log file " + elf);
+          elf.getFile().delete();
           continue;
         }
+        
+        elf.validateLog();
+
+        if (elf.hasCorruptHeader()) {
+          elf.moveAsideCorruptFile();
+          throw new CorruptionException("In-progress edit log file is corrupt: "
+              + elf);
+        }
+        
+        // If the file has a valid header (isn't corrupt) but contains no
+        // transactions, we likely just crashed after opening the file and
+        // writing the header, but before syncing any transactions. Safe to
+        // delete the file.
+        if (elf.getNumTransactions() == 0) {
+          LOG.info("Deleting edit log file with zero transactions " + elf);
+          elf.getFile().delete();
+          continue;
+        }
+        
         finalizeLogSegment(elf.getFirstTxId(), elf.getLastTxId());
       }
     }
@@ -321,15 +335,21 @@ class FileJournalManager implements JournalManager {
 
   /** 
    * Find the maximum transaction in the journal.
-   * This gets stored in a member variable, as corrupt edit logs
-   * will be moved aside, but we still need to remember their first
-   * tranaction id in the case that it was the maximum transaction in
-   * the journal.
    */
   private long findMaxTransaction(boolean inProgressOk)
       throws IOException {
+    boolean considerSeenTxId = true;
+    long seenTxId = NNStorage.readTransactionIdFile(sd);
+    long maxSeenTransaction = 0;
     for (EditLogFile elf : getLogFiles(0)) {
       if (elf.isInProgress() && !inProgressOk) {
+        if (elf.getFirstTxId() != HdfsConstants.INVALID_TXID &&
+            elf.getFirstTxId() <= seenTxId) {
+          // don't look at the seen_txid file if in-progress logs are not to be
+          // examined, and the value in seen_txid falls within the in-progress
+          // segment.
+          considerSeenTxId = false;
+        }
         continue;
       }
       
@@ -339,7 +359,11 @@ class FileJournalManager implements JournalManager {
       }
       maxSeenTransaction = Math.max(elf.getLastTxId(), maxSeenTransaction);
     }
-    return maxSeenTransaction;
+    if (considerSeenTxId) {
+      return Math.max(maxSeenTransaction, seenTxId);
+    } else {
+      return maxSeenTransaction;
+    }
   }
 
   @Override
@@ -354,8 +378,9 @@ class FileJournalManager implements JournalManager {
     private File file;
     private final long firstTxId;
     private long lastTxId;
+    private long numTx = -1;
 
-    private boolean isCorrupt = false;
+    private boolean hasCorruptHeader = false;
     private final boolean isInProgress;
 
     final static Comparator<EditLogFile> COMPARE_BY_START_TXID 
@@ -407,11 +432,13 @@ class FileJournalManager implements JournalManager {
      */
     void validateLog() throws IOException {
       EditLogValidation val = EditLogFileInputStream.validateEditLog(file);
-      if (val.getNumTransactions() == 0) {
+      this.numTx = val.getNumTransactions();
-        markCorrupt();
+      this.lastTxId = val.getEndTxId();
-      } else {
+      this.hasCorruptHeader = val.hasCorruptHeader();
-        this.lastTxId = val.getEndTxId();
+    }
-      }
+    
+    long getNumTransactions() {
+      return numTx;
     }
 
     boolean isInProgress() {
@@ -422,16 +449,12 @@ class FileJournalManager implements JournalManager {
       return file;
     }
     
-    void markCorrupt() {
+    boolean hasCorruptHeader() {
-      isCorrupt = true;
+      return hasCorruptHeader;
-    }
-    
-    boolean isCorrupt() {
-      return isCorrupt;
     }
 
     void moveAsideCorruptFile() throws IOException {
-      assert isCorrupt;
+      assert hasCorruptHeader;
     
       File src = file;
       File dst = new File(src.getParent(), src.getName() + ".corrupt");
@@ -446,8 +469,9 @@ class FileJournalManager implements JournalManager {
     @Override
     public String toString() {
       return String.format("EditLogFile(file=%s,first=%019d,last=%019d,"
-                           +"inProgress=%b,corrupt=%b)", file.toString(),
+                           +"inProgress=%b,hasCorruptHeader=%b,numTx=%d)",
-                           firstTxId, lastTxId, isInProgress(), isCorrupt);
+                           file.toString(), firstTxId, lastTxId,
+                           isInProgress(), hasCorruptHeader, numTx);
     }
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/ha/EditLogTailer.java

@@ -224,7 +224,7 @@ public class EditLogTailer {
         editsLoaded = elie.getNumEditsLoaded();
         throw elie;
       } finally {
-        if (editsLoaded > 0) {
+        if (editsLoaded > 0 || LOG.isDebugEnabled()) {
           LOG.info(String.format("Loaded %d edits starting from txid %d ",
               editsLoaded, lastTxnId));
         }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/NameNodeAdapter.java

@@ -17,6 +17,7 @@
  */
 package org.apache.hadoop.hdfs.server.namenode;
 
+import java.io.File;
 import java.io.IOException;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 
@@ -27,6 +28,7 @@ import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
 import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
 import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenSecretManager;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeDescriptor;
+import org.apache.hadoop.hdfs.server.common.Storage.StorageDirectory;
 import org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.MkdirOp;
 import org.apache.hadoop.hdfs.server.namenode.LeaseManager.Lease;
 import org.apache.hadoop.hdfs.server.namenode.FSNamesystem.SafeModeInfo;
@@ -35,7 +37,6 @@ import org.apache.hadoop.hdfs.server.protocol.HeartbeatResponse;
 import org.apache.hadoop.ipc.Server;
 import org.apache.hadoop.ipc.StandbyException;
 import org.apache.hadoop.security.AccessControlException;
-import org.apache.hadoop.test.GenericTestUtils;
 import org.mockito.Mockito;
 
 /**
@@ -204,4 +205,8 @@ public class NameNodeAdapter {
     }
     return smi.initializedReplQueues;
   }
+  
+  public static File getInProgressEditsFile(StorageDirectory sd, long startTxId) {
+    return NNStorage.getInProgressEditsFile(sd, startTxId);
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestEditLog.java

@@ -629,22 +629,26 @@ public class TestEditLog extends TestCase {
     }
   }
   
+  // should succeed - only one corrupt log dir
   public void testCrashRecoveryEmptyLogOneDir() throws Exception {
-    doTestCrashRecoveryEmptyLog(false, true);
+    doTestCrashRecoveryEmptyLog(false, true, true);
   }
   
+  // should fail - seen_txid updated to 3, but no log dir contains txid 3
   public void testCrashRecoveryEmptyLogBothDirs() throws Exception {
-    doTestCrashRecoveryEmptyLog(true, true);
+    doTestCrashRecoveryEmptyLog(true, true, false);
   }
 
+  // should succeed - only one corrupt log dir
   public void testCrashRecoveryEmptyLogOneDirNoUpdateSeenTxId() 
       throws Exception {
-    doTestCrashRecoveryEmptyLog(false, false);
+    doTestCrashRecoveryEmptyLog(false, false, true);
   }
   
+  // should succeed - both log dirs corrupt, but seen_txid never updated
   public void testCrashRecoveryEmptyLogBothDirsNoUpdateSeenTxId()
       throws Exception {
-    doTestCrashRecoveryEmptyLog(true, false);
+    doTestCrashRecoveryEmptyLog(true, false, true);
   }
 
   /**
@@ -660,12 +664,13 @@ public class TestEditLog extends TestCase {
    * NN should fail to start up, because it's aware that txid 3
    * was reached, but unable to find a non-corrupt log starting there.
    * @param updateTransactionIdFile if true update the seen_txid file.
-   * If false, the it will not be updated. This will simulate a case 
+   * If false, it will not be updated. This will simulate a case where
-   * where the NN crashed between creating the new segment and updating
+   * the NN crashed between creating the new segment and updating the
-   * seen_txid. 
+   * seen_txid file.
+   * @param shouldSucceed true if the test is expected to succeed.
    */
   private void doTestCrashRecoveryEmptyLog(boolean inBothDirs, 
-                                           boolean updateTransactionIdFile) 
+      boolean updateTransactionIdFile, boolean shouldSucceed)
       throws Exception {
     // start a cluster 
     Configuration conf = new HdfsConfiguration();
@@ -684,29 +689,40 @@ public class TestEditLog extends TestCase {
       // Make a truncated edits_3_inprogress
       File log = new File(currentDir,
           NNStorage.getInProgressEditsFileName(3));
-      NNStorage storage = new NNStorage(conf, 
-                                        Collections.<URI>emptyList(),
-                                        Lists.newArrayList(uri));
-      if (updateTransactionIdFile) {
-        storage.writeTransactionIdFileToStorage(3);
-      }
-      storage.close();
 
       new EditLogFileOutputStream(log, 1024).create();
       if (!inBothDirs) {
         break;
       }
+      
+      NNStorage storage = new NNStorage(conf, 
+          Collections.<URI>emptyList(),
+          Lists.newArrayList(uri));
+      
+      if (updateTransactionIdFile) {
+        storage.writeTransactionIdFileToStorage(3);
+      }
+      storage.close();
     }
     
     try {
       cluster = new MiniDFSCluster.Builder(conf)
         .numDataNodes(NUM_DATA_NODES).format(false).build();
-      fail("Did not fail to start with all-corrupt logs");
+      if (!shouldSucceed) {
+        fail("Should not have succeeded in startin cluster");
+      }
     } catch (IOException ioe) {
-      GenericTestUtils.assertExceptionContains(
+      if (shouldSucceed) {
-          "No non-corrupt logs for txid 3", ioe);
+        LOG.info("Should have succeeded in starting cluster, but failed", ioe);
+        throw ioe;
+      } else {
+        GenericTestUtils.assertExceptionContains(
+            "No non-corrupt logs for txid 3",
+            ioe);
+      }
+    } finally {
+      cluster.shutdown();
     }
-    cluster.shutdown();
   }
 
   
@@ -1082,9 +1098,7 @@ public class TestEditLog extends TestCase {
     editlog.initJournalsForWrite();
     long startTxId = 1;
     try {
-      Iterable<EditLogInputStream> editStreams 
+      editlog.selectInputStreams(startTxId, 4*TXNS_PER_ROLL);
-        = editlog.selectInputStreams(startTxId, 4*TXNS_PER_ROLL);
-      
       fail("Should have thrown exception");
     } catch (IOException ioe) {
       GenericTestUtils.assertExceptionContains(

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSEditLogLoader.java

@@ -243,7 +243,9 @@ public class TestFSEditLogLoader {
       Files.copy(logFileBak, logFile);
       corruptByteInFile(logFile, offset);
       EditLogValidation val = EditLogFileInputStream.validateEditLog(logFile);
-      assertTrue(val.getNumTransactions() >= prevNumValid);
+      assertTrue(String.format("%d should have been >= %d",
+          val.getNumTransactions(), prevNumValid),
+          val.getNumTransactions() >= prevNumValid);
       prevNumValid = val.getNumTransactions();
     }
   }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFileJournalManager.java

@@ -255,7 +255,8 @@ public class TestFileJournalManager {
       jm.getNumberOfTransactions(startGapTxId, true);
       fail("Should have thrown an exception by now");
     } catch (IOException ioe) {
-      assertTrue(true);
+      GenericTestUtils.assertExceptionContains(
+          "Gap in transactions, max txnid is 110, 0 txns from 31", ioe);
     }
 
     // rolled 10 times so there should be 11 files.

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/ha/TestHAStateTransitions.java

@@ -17,14 +17,22 @@
  */
 package org.apache.hadoop.hdfs.server.namenode.ha;
 
-import static org.junit.Assert.*;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
+import java.io.DataOutputStream;
+import java.io.File;
+import java.io.FileOutputStream;
 import java.io.IOException;
+import java.net.URI;
 import java.net.URISyntaxException;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.apache.commons.logging.impl.Log4JLogger;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FSDataOutputStream;
 import org.apache.hadoop.fs.FileSystem;
@@ -33,7 +41,10 @@ import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.DFSTestUtil;
 import org.apache.hadoop.hdfs.MiniDFSCluster;
 import org.apache.hadoop.hdfs.MiniDFSNNTopology;
+import org.apache.hadoop.hdfs.protocol.HdfsConstants;
 import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenIdentifier;
+import org.apache.hadoop.hdfs.server.common.Storage.StorageDirectory;
+import org.apache.hadoop.hdfs.server.namenode.EditLogFileOutputStream;
 import org.apache.hadoop.hdfs.server.namenode.NameNode;
 import org.apache.hadoop.hdfs.server.namenode.NameNodeAdapter;
 import org.apache.hadoop.io.IOUtils;
@@ -41,8 +52,9 @@ import org.apache.hadoop.io.Text;
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.security.token.Token;
 import org.apache.hadoop.test.GenericTestUtils;
-import org.apache.hadoop.test.MultithreadedTestUtil.TestContext;
 import org.apache.hadoop.test.MultithreadedTestUtil.RepeatingTestThread;
+import org.apache.hadoop.test.MultithreadedTestUtil.TestContext;
+import org.apache.log4j.Level;
 import org.junit.Assert;
 import org.junit.Test;
 import org.mockito.Mockito;
@@ -59,6 +71,10 @@ public class TestHAStateTransitions {
   private static final String TEST_FILE_STR = TEST_FILE_PATH.toUri().getPath();
   private static final String TEST_FILE_DATA =
     "Hello state transitioning world";
+  
+  static {
+    ((Log4JLogger)EditLogTailer.LOG).getLogger().setLevel(Level.ALL);
+  }
 
   /**
    * Test which takes a single node and flip flops between
@@ -354,4 +370,55 @@ public class TestHAStateTransitions {
       cluster.shutdown();
     }
   }
+
+  @Test
+  public void testFailoverWithEmptyInProgressEditLog() throws Exception {
+    testFailoverAfterCrashDuringLogRoll(false);
+  }
+  
+  @Test
+  public void testFailoverWithEmptyInProgressEditLogWithHeader()
+      throws Exception {
+    testFailoverAfterCrashDuringLogRoll(true);
+  }
+  
+  private static void testFailoverAfterCrashDuringLogRoll(boolean writeHeader)
+      throws Exception {
+    Configuration conf = new Configuration();
+    conf.setInt(DFSConfigKeys.DFS_HA_TAILEDITS_PERIOD_KEY, Integer.MAX_VALUE);
+    MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf)
+      .nnTopology(MiniDFSNNTopology.simpleHATopology())
+      .numDataNodes(0)
+      .build();
+    FileSystem fs = HATestUtil.configureFailoverFs(cluster, conf);
+    try {
+      cluster.transitionToActive(0);
+      NameNode nn0 = cluster.getNameNode(0);
+      nn0.getRpcServer().rollEditLog();
+      cluster.shutdownNameNode(0);
+      createEmptyInProgressEditLog(cluster, nn0, writeHeader);
+      cluster.transitionToActive(1);
+    } finally {
+      IOUtils.cleanup(LOG, fs);
+      cluster.shutdown();
+    }
+  }
+  
+  private static void createEmptyInProgressEditLog(MiniDFSCluster cluster,
+      NameNode nn, boolean writeHeader) throws IOException {
+    long txid = nn.getNamesystem().getEditLog().getLastWrittenTxId();
+    URI sharedEditsUri = cluster.getSharedEditsDir(0, 1);
+    File sharedEditsDir = new File(sharedEditsUri.getPath());
+    StorageDirectory storageDir = new StorageDirectory(sharedEditsDir);
+    File inProgressFile = NameNodeAdapter.getInProgressEditsFile(storageDir,
+        txid + 1);
+    assertTrue("Failed to create in-progress edits file",
+        inProgressFile.createNewFile());
+    
+    if (writeHeader) {
+      DataOutputStream out = new DataOutputStream(new FileOutputStream(
+          inProgressFile));
+      EditLogFileOutputStream.writeHeader(out);
+    }
+  }
 }

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

@@ -80,8 +80,8 @@ public abstract class GenericTestUtils {
   public static void assertExceptionContains(String string, Throwable t) {
     String msg = t.getMessage();
     Assert.assertTrue(
-        "Unexpected exception:" + StringUtils.stringifyException(t),
+        "Expected to find '" + string + "' but got unexpected exception:"
-        msg.contains(string));    
+        + StringUtils.stringifyException(t), msg.contains(string));
   }  
 
   public static void waitFor(Supplier<Boolean> check,