HDFS-3849. When re-loading the FSImage, we should clear the existing genStamp and leases. Contributed by Colin Patrick McCabe.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1378364 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -690,6 +690,9 @@ Branch-2 ( Unreleased changes )
     HDFS-3860. HeartbeatManager#Monitor may wrongly hold the writelock of
     namesystem. (Jing Zhao via atm)
 
+    HDFS-3849. When re-loading the FSImage, we should clear the existing
+    genStamp and leases. (Colin Patrick McCabe via atm)
+
   BREAKDOWN OF HDFS-3042 SUBTASKS
 
     HDFS-2185. HDFS portion of ZK-based FailoverController (todd)

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

@@ -38,6 +38,7 @@ import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
 import org.apache.hadoop.hdfs.protocol.LayoutVersion;
 import org.apache.hadoop.hdfs.protocol.LayoutVersion.Feature;
+import org.apache.hadoop.hdfs.server.common.GenerationStamp;
 import org.apache.hadoop.hdfs.server.common.InconsistentFSStateException;
 import org.apache.hadoop.hdfs.server.common.Storage;
 import org.apache.hadoop.hdfs.server.common.Storage.FormatConfirmable;
@@ -555,9 +556,7 @@ public class FSImage implements Closeable {
    * file.
    */
   void reloadFromImageFile(File file, FSNamesystem target) throws IOException {
-    target.dir.reset();
-    target.dtSecretManager.reset();
-
+    target.clear();
     LOG.debug("Reloading namespace from " + file);
     loadFSImage(file, target, null);
   }

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

@@ -365,6 +365,23 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
 
   private final boolean haEnabled;
     
+  /**
+   * Clear all loaded data
+   */
+  void clear() {
+    dir.reset();
+    dtSecretManager.reset();
+    generationStamp.setStamp(GenerationStamp.FIRST_VALID_STAMP);
+    leaseManager.removeAllLeases();
+  }
+
+  @VisibleForTesting
+  LeaseManager getLeaseManager() {
+    return leaseManager;
+  }
+  
+  /**
+
   /**
    * Instantiates an FSNamesystem loaded from the image and edits
    * directories specified in the passed Configuration.

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

@@ -159,6 +159,12 @@ public class LeaseManager {
     }
   }
 
+  synchronized void removeAllLeases() {
+    sortedLeases.clear();
+    sortedLeasesByPath.clear();
+    leases.clear();
+  }
+
   /**
    * Reassign lease for file src to the new holder.
    */

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

@@ -140,6 +140,11 @@ public class SecondaryNameNode implements Runnable {
   FSImage getFSImage() {
     return checkpointImage;
   }
+
+  @VisibleForTesting
+  FSNamesystem getFSNamesystem() {
+    return namesystem;
+  }
   
   @VisibleForTesting
   void setFSImage(CheckpointStorage image) {

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

@@ -1924,6 +1924,59 @@ public class TestCheckpoint {
       }
     }
   }
+
+  /**
+   * Regression test for HDFS-3849.  This makes sure that when we re-load the
+   * FSImage in the 2NN, we clear the existing leases.
+   */
+  @Test
+  public void testSecondaryNameNodeWithSavedLeases() throws IOException {
+    MiniDFSCluster cluster = null;
+    SecondaryNameNode secondary = null;
+    FSDataOutputStream fos = null;
+    Configuration conf = new HdfsConfiguration();
+    try {
+      cluster = new MiniDFSCluster.Builder(conf).numDataNodes(numDatanodes)
+          .format(true).build();
+      FileSystem fs = cluster.getFileSystem();
+      fos = fs.create(new Path("tmpfile"));
+      fos.write(new byte[] { 0, 1, 2, 3 });
+      fos.hflush();
+      assertEquals(1, cluster.getNamesystem().getLeaseManager().countLease());
+
+      secondary = startSecondaryNameNode(conf);
+      assertEquals(0, secondary.getFSNamesystem().getLeaseManager().countLease());
+
+      // Checkpoint once, so the 2NN loads the lease into its in-memory sate.
+      secondary.doCheckpoint();
+      assertEquals(1, secondary.getFSNamesystem().getLeaseManager().countLease());
+      fos.close();
+      fos = null;
+
+      // Perform a saveNamespace, so that the NN has a new fsimage, and the 2NN
+      // therefore needs to download a new fsimage the next time it performs a
+      // checkpoint.
+      cluster.getNameNodeRpc().setSafeMode(SafeModeAction.SAFEMODE_ENTER);
+      cluster.getNameNodeRpc().saveNamespace();
+      cluster.getNameNodeRpc().setSafeMode(SafeModeAction.SAFEMODE_LEAVE);
+      
+      // Ensure that the 2NN can still perform a checkpoint.
+      secondary.doCheckpoint();
+      
+      // And the leases have been cleared...
+      assertEquals(0, secondary.getFSNamesystem().getLeaseManager().countLease());
+    } finally {
+      if (fos != null) {
+        fos.close();
+      }
+      if (secondary != null) {
+        secondary.shutdown();
+      }
+      if (cluster != null) {
+        cluster.shutdown();
+      }
+    }
+  }
   
   @Test
   public void testCommandLineParsing() throws ParseException {

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

@@ -26,6 +26,9 @@ import java.net.URI;
 import java.util.Collection;
 
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hdfs.DFSTestUtil;
+import org.apache.hadoop.hdfs.HdfsConfiguration;
+import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.NamenodeRole;
 import org.junit.Test;
 
 public class TestFSNamesystem {
@@ -45,4 +48,20 @@ public class TestFSNamesystem {
     assertEquals(2, editsDirs.size());
   }
 
+  /**
+   * Test that FSNamesystem#clear clears all leases.
+   */
+  @Test
+  public void testFSNamespaceClearLeases() throws Exception {
+    Configuration conf = new HdfsConfiguration();
+    NameNode.initMetrics(conf, NamenodeRole.NAMENODE);
+    DFSTestUtil.formatNameNode(conf);
+    FSNamesystem fsn = FSNamesystem.loadFromDisk(conf);
+    LeaseManager leaseMan = fsn.getLeaseManager();
+    leaseMan.addLease("client1", "importantFile");
+    assertEquals(1, leaseMan.countLease());
+    fsn.clear();
+    leaseMan = fsn.getLeaseManager();
+    assertEquals(0, leaseMan.countLease());
+  }
 }