HDFS-9569. Log the name of the fsimage being loaded for better supportability. (Yongjun Zhang)

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

@@ -2600,6 +2600,9 @@ Release 2.7.3 - UNRELEASED
 
     HDFS-9574. Reduce client failures during datanode restart (kihwal)
 
+    HDFS-9569. Log the name of the fsimage being loaded for better
+    supportability. (Yongjun Zhang)
+
   OPTIMIZATIONS
 
   BUG FIXES

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

@@ -665,14 +665,19 @@ public class FSImage implements Closeable {
       LOG.info("No edit log streams selected.");
     }
     
+    Exception le = null;
     FSImageFile imageFile = null;
     for (int i = 0; i < imageFiles.size(); i++) {
       try {
         imageFile = imageFiles.get(i);
         loadFSImageFile(target, recovery, imageFile, startOpt);
         break;
-      } catch (IOException ioe) {
-        LOG.error("Failed to load image from " + imageFile, ioe);
+      } catch (IllegalReservedPathException ie) {
+        throw new IOException("Failed to load image from " + imageFile,
+            ie);
+      } catch (Exception e) {
+        le = e;
+        LOG.error("Failed to load image from " + imageFile, e);
         target.clear();
         imageFile = null;
       }
@@ -680,7 +685,8 @@ public class FSImage implements Closeable {
     // Failed to load any images, error out
     if (imageFile == null) {
       FSEditLog.closeAllStreams(editStreams);
-      throw new IOException("Failed to load an FSImage file!");
+      throw new IOException("Failed to load FSImage file, see error(s) " +
+          "above for more info.");
     }
     prog.endPhase(Phase.LOADING_FSIMAGE);
     
@@ -721,7 +727,7 @@ public class FSImage implements Closeable {
 
   void loadFSImageFile(FSNamesystem target, MetaRecoveryContext recovery,
       FSImageFile imageFile, StartupOption startupOption) throws IOException {
-    LOG.debug("Planning to load image :\n" + imageFile);
+    LOG.info("Planning to load image: " + imageFile);
     StorageDirectory sdForProperties = imageFile.sd;
     storage.readProperties(sdForProperties, startupOption);
 

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

@@ -669,7 +669,8 @@ public class FSImageFormat {
    * This method is only used for image loading so that synchronization,
    * modification time update and space count update are not needed.
    */
-  private void addToParent(INodeDirectory parent, INode child) {
+  private void addToParent(INodeDirectory parent, INode child)
+      throws IllegalReservedPathException {
     FSDirectory fsDir = namesystem.dir;
     if (parent == fsDir.rootDir) {
         child.setLocalName(renameReservedRootComponentOnUpgrade(
@@ -1097,7 +1098,7 @@ public class FSImageFormat {
    * @return New path with reserved path components renamed to user value
    */
   static String renameReservedPathsOnUpgrade(String path,
-      final int layoutVersion) {
+      final int layoutVersion) throws IllegalReservedPathException {
     final String oldPath = path;
     // If any known LVs aren't supported, we're doing an upgrade
     if (!NameNodeLayoutVersion.supports(Feature.ADD_INODE_ID, layoutVersion)) {
@@ -1147,13 +1148,13 @@ public class FSImageFormat {
    * byte array path component.
    */
   private static byte[] renameReservedComponentOnUpgrade(byte[] component,
-      final int layoutVersion) {
+      final int layoutVersion) throws IllegalReservedPathException {
     // If the LV doesn't support snapshots, we're doing an upgrade
     if (!NameNodeLayoutVersion.supports(Feature.SNAPSHOT, layoutVersion)) {
       if (Arrays.equals(component, HdfsServerConstants.DOT_SNAPSHOT_DIR_BYTES)) {
-        Preconditions.checkArgument(
-            renameReservedMap.containsKey(HdfsConstants.DOT_SNAPSHOT_DIR),
-            RESERVED_ERROR_MSG);
+        if (!renameReservedMap.containsKey(HdfsConstants.DOT_SNAPSHOT_DIR)) {
+          throw new IllegalReservedPathException(RESERVED_ERROR_MSG);
+        }
         component =
             DFSUtil.string2Bytes(renameReservedMap
                 .get(HdfsConstants.DOT_SNAPSHOT_DIR));
@@ -1167,13 +1168,13 @@ public class FSImageFormat {
    * byte array path component.
    */
   private static byte[] renameReservedRootComponentOnUpgrade(byte[] component,
-      final int layoutVersion) {
+      final int layoutVersion) throws IllegalReservedPathException {
     // If the LV doesn't support inode IDs, we're doing an upgrade
     if (!NameNodeLayoutVersion.supports(Feature.ADD_INODE_ID, layoutVersion)) {
       if (Arrays.equals(component, FSDirectory.DOT_RESERVED)) {
-        Preconditions.checkArgument(
-            renameReservedMap.containsKey(FSDirectory.DOT_RESERVED_STRING),
-            RESERVED_ERROR_MSG);
+        if (!renameReservedMap.containsKey(HdfsConstants.DOT_SNAPSHOT_DIR)) {
+          throw new IllegalReservedPathException(RESERVED_ERROR_MSG);
+        }
         final String renameString = renameReservedMap
             .get(FSDirectory.DOT_RESERVED_STRING);
         component =

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

@@ -0,0 +1,39 @@
+/**
+ * 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;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+
+/**
+ * Thrown when upgrading from software release that doesn't support reserved
+ * path to software release that supports reserved path, and when there is 
+ * reserved path name in the Fsimage.
+ */
+@InterfaceAudience.Private
+public class IllegalReservedPathException extends IOException {
+  private static final long serialVersionUID = 1L;
+  
+  public IllegalReservedPathException(String message, Throwable cause) {
+    super(message, cause);
+  }
+  public IllegalReservedPathException(String message) {
+    super(message);
+  }
+}

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

@@ -45,6 +45,7 @@ import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.StartupOption;
 import org.apache.hadoop.hdfs.server.namenode.FSImage;
 import org.apache.hadoop.hdfs.server.namenode.FSImageFormat;
 import org.apache.hadoop.hdfs.server.namenode.FSImageTestUtil;
+import org.apache.hadoop.hdfs.server.namenode.IllegalReservedPathException;
 import org.apache.hadoop.test.GenericTestUtils;
 import org.apache.hadoop.util.StringUtils;
 import org.apache.log4j.Logger;
@@ -326,7 +327,7 @@ public class TestDFSUpgradeFromImage {
       fail("Upgrade did not fail with bad MD5");
     } catch (IOException ioe) {
       String msg = StringUtils.stringifyException(ioe);
-      if (!msg.contains("Failed to load an FSImage file")) {
+      if (!msg.contains("Failed to load FSImage file")) {
         throw ioe;
       }
       int md5failures = appender.countExceptionsWithMessage(
@@ -485,10 +486,15 @@ public class TestDFSUpgradeFromImage {
               .format(false)
               .startupOption(StartupOption.UPGRADE)
               .numDataNodes(0).build();
-    } catch (IllegalArgumentException e) {
-      GenericTestUtils.assertExceptionContains(
-          "reserved path component in this version",
-          e);
+    } catch (IOException ioe) {
+        Throwable cause = ioe.getCause();
+        if (cause != null && cause instanceof IllegalReservedPathException) {
+          GenericTestUtils.assertExceptionContains(
+              "reserved path component in this version",
+              cause);
+        } else {
+          throw ioe;
+        }
     } finally {
       if (cluster != null) {
         cluster.shutdown();