HDFS-3597. SNN fails to start after DFS upgrade. Contributed by Andy Isaacson.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1363900 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -362,6 +362,8 @@ Release 2.0.1-alpha - UNRELEASED
 
     HDFS-3690. BlockPlacementPolicyDefault incorrectly casts LOG. (eli)
 
+    HDFS-3597. SNN fails to start after DFS upgrade. (Andy Isaacson via todd)
+
   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/CheckpointSignature.java

@@ -113,12 +113,19 @@ public class CheckpointSignature extends StorageInfo
          + blockpoolID ;
   }
 
+  boolean storageVersionMatches(StorageInfo si) throws IOException {
+    return (layoutVersion == si.layoutVersion) && (cTime == si.cTime);
+  }
+
+  boolean isSameCluster(FSImage si) {
+    return namespaceID == si.getStorage().namespaceID &&
+      clusterID.equals(si.getClusterID()) &&
+      blockpoolID.equals(si.getBlockPoolID());
+  }
+
   void validateStorageInfo(FSImage si) throws IOException {
-    if(layoutVersion != si.getStorage().layoutVersion
-       || namespaceID != si.getStorage().namespaceID 
-       || cTime != si.getStorage().cTime
-       || !clusterID.equals(si.getClusterID())
-       || !blockpoolID.equals(si.getBlockPoolID())) {
+    if (!isSameCluster(si)
+        || !storageVersionMatches(si.getStorage())) {
       throw new IOException("Inconsistent checkpoint fields.\n"
           + "LV = " + layoutVersion + " namespaceID = " + namespaceID
           + " cTime = " + cTime

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

@@ -437,18 +437,16 @@ public class SecondaryNameNode implements Runnable {
     // Returns a token that would be used to upload the merged image.
     CheckpointSignature sig = namenode.rollEditLog();
     
-    // Make sure we're talking to the same NN!
-    if (checkpointImage.getNamespaceID() != 0) {
-      // If the image actually has some data, make sure we're talking
-      // to the same NN as we did before.
-      sig.validateStorageInfo(checkpointImage);
-    } else {
-      // if we're a fresh 2NN, just take the storage info from the server
-      // we first talk to.
+    if ((checkpointImage.getNamespaceID() == 0) ||
+        (sig.isSameCluster(checkpointImage) &&
+         !sig.storageVersionMatches(checkpointImage.getStorage()))) {
+      // if we're a fresh 2NN, or if we're on the same cluster and our storage
+      // needs an upgrade, just take the storage info from the server.
       dstStorage.setStorageInfo(sig);
       dstStorage.setClusterID(sig.getClusterID());
       dstStorage.setBlockPoolID(sig.getBlockpoolID());
     }
+    sig.validateStorageInfo(checkpointImage);
 
     // error simulation code for junit test
     CheckpointFaultInjector.getInstance().afterSecondaryCallsRollEditLog();
@@ -703,7 +701,7 @@ public class SecondaryNameNode implements Runnable {
     /**
      * Analyze checkpoint directories.
      * Create directories if they do not exist.
-     * Recover from an unsuccessful checkpoint is necessary.
+     * Recover from an unsuccessful checkpoint if necessary.
      *
      * @throws IOException
      */

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

@@ -0,0 +1,116 @@
+/**
+ * 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.File;
+import java.io.IOException;
+import java.util.List;
+
+import org.junit.Test;
+import org.junit.Before;
+import org.junit.After;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FSDataOutputStream;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.fs.FileUtil;
+
+import org.apache.hadoop.hdfs.DFSConfigKeys;
+import org.apache.hadoop.hdfs.HdfsConfiguration;
+import org.apache.hadoop.hdfs.MiniDFSCluster;
+
+import java.util.Properties;
+import java.io.FileReader;
+import java.io.FileWriter;
+import org.junit.Assert;
+import org.apache.hadoop.test.GenericTestUtils;
+
+/**
+ * Regression test for HDFS-3597, SecondaryNameNode upgrade -- when a 2NN
+ * starts up with an existing directory structure with an old VERSION file, it
+ * should delete the snapshot and download a new one from the NN.
+ */
+public class TestSecondaryNameNodeUpgrade {
+
+  @Before
+  public void cleanupCluster() throws IOException {
+    File hdfsDir = new File(MiniDFSCluster.getBaseDirectory()).getCanonicalFile();
+    System.out.println("cleanupCluster deleting " + hdfsDir);
+    if (hdfsDir.exists() && !FileUtil.fullyDelete(hdfsDir)) {
+      throw new IOException("Could not delete hdfs directory '" + hdfsDir + "'");
+    }
+  }
+
+  private void doIt(String param, String val) throws IOException {
+    MiniDFSCluster cluster = null;
+    FileSystem fs = null;
+    SecondaryNameNode snn = null;
+
+    try {
+      Configuration conf = new HdfsConfiguration();
+
+      cluster = new MiniDFSCluster.Builder(conf).build();
+      cluster.waitActive();
+
+      conf.set(DFSConfigKeys.DFS_NAMENODE_SECONDARY_HTTP_ADDRESS_KEY, "0.0.0.0:0");
+      snn = new SecondaryNameNode(conf);
+
+      fs = cluster.getFileSystem();
+
+      fs.mkdirs(new Path("/test/foo"));
+
+      snn.doCheckpoint();
+
+      List<File> versionFiles = snn.getFSImage().getStorage().getFiles(null, "VERSION");
+
+      snn.shutdown();
+
+      for (File versionFile : versionFiles) {
+        System.out.println("Changing '" + param + "' to '" + val + "' in " + versionFile);
+        FSImageTestUtil.corruptVersionFile(versionFile, param, val);
+      }
+
+      snn = new SecondaryNameNode(conf);
+
+      fs.mkdirs(new Path("/test/bar"));
+
+      snn.doCheckpoint();
+    } finally {
+      if (fs != null) fs.close();
+      if (cluster != null) cluster.shutdown();
+      if (snn != null) snn.shutdown();
+    }
+  }
+
+  @Test
+  public void testUpgradeLayoutVersionSucceeds() throws IOException {
+    doIt("layoutVersion", "-39");
+  }
+
+  @Test
+  public void testChangeNsIDFails() throws IOException {
+    try {
+      doIt("namespaceID", "2");
+      Assert.fail("Should throw InconsistentFSStateException");
+    } catch(IOException e) {
+      GenericTestUtils.assertExceptionContains("Inconsistent checkpoint fields", e);
+      System.out.println("Correctly failed with inconsistent namespaceID: " + e);
+    }
+  }
+}