HDFS-3678. Edit log files are never being purged from 2NN. Contributed by Aaron T. Myers.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1377046 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -203,6 +203,8 @@ Trunk (unreleased changes)
     HDFS-3834. Remove unused static fields NAME, DESCRIPTION and Usage from
     Command. (Jing Zhao via suresh)
 
+    HDFS-3678. Edit log files are never being purged from 2NN. (atm)
+
 Branch-2 ( Unreleased changes )
 
   INCOMPATIBLE CHANGES

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

@@ -83,7 +83,7 @@
  */
 @InterfaceAudience.Private
 @InterfaceStability.Evolving
-public class FSEditLog  {
+public class FSEditLog implements LogsPurgeable {
 
   static final Log LOG = LogFactory.getLog(FSEditLog.class);
 
@@ -1032,6 +1032,7 @@ synchronized void abortCurrentLogSegment() {
   /**
    * Archive any log files that are older than the given txid.
    */
+  @Override
   public synchronized void purgeLogsOlderThan(final long minTxIdToKeep) {
     assert curSegmentTxId == HdfsConstants.INVALID_TXID || // on format this is no-op
       minTxIdToKeep <= curSegmentTxId :

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

@@ -91,7 +91,7 @@ public class FSImage implements Closeable {
 
   final private Configuration conf;
 
-  private final NNStorageRetentionManager archivalManager;
+  protected NNStorageRetentionManager archivalManager;
 
   /**
    * Construct an FSImage

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

@@ -35,7 +35,8 @@
  */
 @InterfaceAudience.Private
 @InterfaceStability.Evolving
-public interface JournalManager extends Closeable, FormatConfirmable {
+public interface JournalManager extends Closeable, FormatConfirmable,
+    LogsPurgeable {
 
   /**
    * Format the underlying storage, removing any previously
@@ -73,17 +74,6 @@ void selectInputStreams(Collection<EditLogInputStream> streams,
    */
   void setOutputBufferCapacity(int size);
 
-  /**
-   * The JournalManager may archive/purge any logs for transactions less than
-   * or equal to minImageTxId.
-   *
-   * @param minTxIdToKeep the earliest txid that must be retained after purging
-   *                      old logs
-   * @throws IOException if purging fails
-   */
-  void purgeLogsOlderThan(long minTxIdToKeep)
-    throws IOException;
-
   /**
    * Recover segments which have not been finalized.
    */

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

@@ -0,0 +1,37 @@
+/**
+ * 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.server.namenode;
+
+import java.io.IOException;
+
+/**
+ * Interface used to abstract over classes which manage edit logs that may need
+ * to be purged.
+ */
+interface LogsPurgeable {
+  
+  /**
+   * Remove all edit logs with transaction IDs lower than the given transaction
+   * ID.
+   * 
+   * @param minTxIdToKeep the lowest transaction ID that should be retained
+   * @throws IOException in the event of error
+   */
+  public void purgeLogsOlderThan(long minTxIdToKeep) throws IOException;
+
+}

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

@@ -52,12 +52,12 @@ public class NNStorageRetentionManager {
       NNStorageRetentionManager.class);
   private final NNStorage storage;
   private final StoragePurger purger;
-  private final FSEditLog editLog;
+  private final LogsPurgeable purgeableLogs;
   
   public NNStorageRetentionManager(
       Configuration conf,
       NNStorage storage,
-      FSEditLog editLog,
+      LogsPurgeable purgeableLogs,
       StoragePurger purger) {
     this.numCheckpointsToRetain = conf.getInt(
         DFSConfigKeys.DFS_NAMENODE_NUM_CHECKPOINTS_RETAINED_KEY,
@@ -72,13 +72,13 @@ public NNStorageRetentionManager(
         " must not be negative");
     
     this.storage = storage;
-    this.editLog = editLog;
+    this.purgeableLogs = purgeableLogs;
     this.purger = purger;
   }
   
   public NNStorageRetentionManager(Configuration conf, NNStorage storage,
-      FSEditLog editLog) {
+      LogsPurgeable purgeableLogs) {
-    this(conf, storage, editLog, new DeletionStoragePurger());
+    this(conf, storage, purgeableLogs, new DeletionStoragePurger());
   }
 
   public void purgeOldStorage() throws IOException {
@@ -95,7 +95,7 @@ public void purgeOldStorage() throws IOException {
     // handy for HA, where a remote node may not have as many
     // new images.
     long purgeLogsFrom = Math.max(0, minImageTxId + 1 - numExtraEditsToRetain);
-    editLog.purgeLogsOlderThan(purgeLogsFrom);
+    purgeableLogs.purgeLogsOlderThan(purgeLogsFrom);
   }
   
   private void purgeCheckpointsOlderThan(
@@ -103,7 +103,6 @@ private void purgeCheckpointsOlderThan(
       long minTxId) {
     for (FSImageFile image : inspector.getFoundImages()) {
       if (image.getCheckpointTxId() < minTxId) {
-        LOG.info("Purging old image " + image);
         purger.purgeImage(image);
       }
     }
@@ -146,11 +145,13 @@ static interface StoragePurger {
   static class DeletionStoragePurger implements StoragePurger {
     @Override
     public void purgeLog(EditLogFile log) {
+      LOG.info("Purging old edit log " + log);
       deleteOrWarn(log.getFile());
     }
 
     @Override
     public void purgeImage(FSImageFile image) {
+      LOG.info("Purging old image " + image);
       deleteOrWarn(image.getFile());
       deleteOrWarn(MD5FileUtils.getDigestFileForFile(image.getFile()));
     }

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

@@ -58,6 +58,8 @@
 
 import static org.apache.hadoop.util.ExitUtil.terminate;
 
+import org.apache.hadoop.hdfs.server.namenode.FileJournalManager.EditLogFile;
+import org.apache.hadoop.hdfs.server.namenode.NNStorageRetentionManager.StoragePurger;
 import org.apache.hadoop.hdfs.server.protocol.NamenodeProtocol;
 import org.apache.hadoop.hdfs.server.protocol.RemoteEditLog;
 import org.apache.hadoop.hdfs.server.protocol.RemoteEditLogManifest;
@@ -473,10 +475,6 @@ boolean doCheckpoint() throws IOException {
     LOG.warn("Checkpoint done. New Image Size: " 
              + dstStorage.getFsImageName(txid).length());
     
-    // Since we've successfully checkpointed, we can remove some old
-    // image files
-    checkpointImage.purgeOldStorage();
-    
     return loadImage;
   }
   
@@ -703,6 +701,34 @@ private static CommandLineOpts parseArgs(String[] argv) {
   }
   
   static class CheckpointStorage extends FSImage {
+    
+    private static class CheckpointLogPurger implements LogsPurgeable {
+      
+      private NNStorage storage;
+      private StoragePurger purger
+          = new NNStorageRetentionManager.DeletionStoragePurger();
+      
+      public CheckpointLogPurger(NNStorage storage) {
+        this.storage = storage;
+      }
+
+      @Override
+      public void purgeLogsOlderThan(long minTxIdToKeep) throws IOException {
+        Iterator<StorageDirectory> iter = storage.dirIterator();
+        while (iter.hasNext()) {
+          StorageDirectory dir = iter.next();
+          List<EditLogFile> editFiles = FileJournalManager.matchEditLogs(
+              dir.getCurrentDir());
+          for (EditLogFile f : editFiles) {
+            if (f.getLastTxId() < minTxIdToKeep) {
+              purger.purgeLog(f);
+            }
+          }
+        }
+      }
+      
+    }
+    
     /**
      * Construct a checkpoint image.
      * @param conf Node configuration.
@@ -719,6 +745,11 @@ static class CheckpointStorage extends FSImage {
       // we shouldn't have any editLog instance. Setting to null
       // makes sure we don't accidentally depend on it.
       editLog = null;
+      
+      // Replace the archival manager with one that can actually work on the
+      // 2NN's edits storage.
+      this.archivalManager = new NNStorageRetentionManager(conf, storage,
+          new CheckpointLogPurger(storage));
     }
 
     /**
@@ -815,6 +846,7 @@ static void doMerge(
     }
     
     Checkpointer.rollForwardByApplyingLogs(manifest, dstImage, dstNamesystem);
+    // The following has the side effect of purging old fsimages/edit logs.
     dstImage.saveFSImageInAllDirs(dstNamesystem, dstImage.getLastAppliedTxId());
     dstStorage.writeAll();
   }

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

@@ -28,6 +28,7 @@
 import static org.junit.Assert.fail;
 
 import java.io.File;
+import java.io.FilenameFilter;
 import java.io.IOException;
 import java.lang.management.ManagementFactory;
 import java.net.InetSocketAddress;
@@ -60,6 +61,7 @@
 import org.apache.hadoop.hdfs.server.common.Storage;
 import org.apache.hadoop.hdfs.server.common.Storage.StorageDirectory;
 import org.apache.hadoop.hdfs.server.common.StorageInfo;
+import org.apache.hadoop.hdfs.server.namenode.FileJournalManager.EditLogFile;
 import org.apache.hadoop.hdfs.server.namenode.NNStorage.NameNodeDirType;
 import org.apache.hadoop.hdfs.server.namenode.SecondaryNameNode.CheckpointStorage;
 import org.apache.hadoop.hdfs.server.protocol.NamenodeProtocol;
@@ -1836,6 +1838,50 @@ public void testSecondaryHasVeryOutOfDateImage() throws IOException {
     }
   }
   
+  /**
+   * Regression test for HDFS-3678 "Edit log files are never being purged from 2NN"
+   */
+  @Test
+  public void testSecondaryPurgesEditLogs() throws IOException {
+    MiniDFSCluster cluster = null;
+    SecondaryNameNode secondary = null;
+    
+    Configuration conf = new HdfsConfiguration();
+    conf.setInt(DFSConfigKeys.DFS_NAMENODE_NUM_EXTRA_EDITS_RETAINED_KEY, 0);
+    try {
+      cluster = new MiniDFSCluster.Builder(conf).numDataNodes(0)
+          .format(true).build();
+      
+      FileSystem fs = cluster.getFileSystem();
+      fs.mkdirs(new Path("/foo"));
+  
+      secondary = startSecondaryNameNode(conf);
+      
+      // Checkpoint a few times. Doing this will cause a log roll, and thus
+      // several edit log segments on the 2NN.
+      for (int i = 0; i < 5; i++) {
+        secondary.doCheckpoint();
+      }
+      
+      // Make sure there are no more edit log files than there should be.
+      List<File> checkpointDirs = getCheckpointCurrentDirs(secondary);
+      for (File checkpointDir : checkpointDirs) {
+        List<EditLogFile> editsFiles = FileJournalManager.matchEditLogs(
+            checkpointDir);
+        assertEquals("Edit log files were not purged from 2NN", 1,
+            editsFiles.size());
+      }
+      
+    } finally {
+      if (secondary != null) {
+        secondary.shutdown();
+      }
+      if (cluster != null) {
+        cluster.shutdown();
+      }
+    }
+  }
+  
   /**
    * Regression test for HDFS-3835 - "Long-lived 2NN cannot perform a
    * checkpoint if security is enabled and the NN restarts without outstanding
@@ -1940,7 +1986,7 @@ private void assertParallelFilesInvariant(MiniDFSCluster cluster,
         ImmutableSet.of("VERSION"));    
   }
   
-  private List<File> getCheckpointCurrentDirs(SecondaryNameNode secondary) {
+  private static List<File> getCheckpointCurrentDirs(SecondaryNameNode secondary) {
     List<File> ret = Lists.newArrayList();
     for (URI u : secondary.getCheckpointDirs()) {
       File checkpointDir = new File(u.getPath());
@@ -1949,7 +1995,7 @@ private List<File> getCheckpointCurrentDirs(SecondaryNameNode secondary) {
     return ret;
   }
 
-  private CheckpointStorage spyOnSecondaryImage(SecondaryNameNode secondary1) {
+  private static CheckpointStorage spyOnSecondaryImage(SecondaryNameNode secondary1) {
     CheckpointStorage spy = Mockito.spy((CheckpointStorage)secondary1.getFSImage());;
     secondary1.setFSImage(spy);
     return spy;