HDFS-3522. If a namenode is in safemode, it should throw SafeModeException when getBlockLocations has zero locations. Contributed by Brandon Li

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1349088 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -316,6 +316,9 @@ Branch-2 ( Unreleased changes )
 
     HDFS-3517. TestStartup should bind ephemeral ports. (eli)
 
+    HDFS-3522. If a namenode is in safemode, it should throw SafeModeException
+    when getBlockLocations has zero locations.  (Brandon Li via szetszwo)
+
   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/FSNamesystem.java

@@ -1089,7 +1089,8 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
   LocatedBlocks getBlockLocations(String clientMachine, String src,
       long offset, long length) throws AccessControlException,
       FileNotFoundException, UnresolvedLinkException, IOException {
-    LocatedBlocks blocks = getBlockLocations(src, offset, length, true, true);
+    LocatedBlocks blocks = getBlockLocations(src, offset, length, true, true,
+        true);
     if (blocks != null) {
       blockManager.getDatanodeManager().sortLocatedBlocks(
           clientMachine, blocks.getLocatedBlocks());
@@ -1103,8 +1104,8 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
    * @throws FileNotFoundException, UnresolvedLinkException, IOException
    */
   LocatedBlocks getBlockLocations(String src, long offset, long length,
-      boolean doAccessTime, boolean needBlockToken) throws FileNotFoundException,
-      UnresolvedLinkException, IOException {
+      boolean doAccessTime, boolean needBlockToken, boolean checkSafeMode)
+      throws FileNotFoundException, UnresolvedLinkException, IOException {
     if (isPermissionEnabled) {
       checkPathAccess(src, FsAction.READ);
     }
@@ -1124,6 +1125,15 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
                     Server.getRemoteIp(),
                     "open", src, null, null);
     }
+    if (checkSafeMode && isInSafeMode()) {
+      for (LocatedBlock b : ret.getLocatedBlocks()) {
+        // if safemode & no block locations yet then throw safemodeException
+        if ((b.getLocations() == null) || (b.getLocations().length == 0)) {
+          throw new SafeModeException("Zero blocklocations for " + src,
+              safeMode);
+        }
+      }
+    }
     return ret;
   }
 

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

@@ -277,7 +277,7 @@ public class NamenodeFsck {
     // Get block locations without updating the file access time 
     // and without block access tokens
     LocatedBlocks blocks = namenode.getNamesystem().getBlockLocations(path, 0,
-        fileLen, false, false);
+        fileLen, false, false, false);
     if (blocks == null) { // the file is deleted
       return;
     }

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

@@ -23,6 +23,7 @@ import java.util.List;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FSDataOutputStream;
+import org.apache.hadoop.fs.FileStatus;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.permission.FsPermission;
@@ -31,9 +32,11 @@ import org.apache.hadoop.hdfs.protocol.HdfsConstants.SafeModeAction;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockManagerTestUtil;
 import org.apache.hadoop.hdfs.server.namenode.FSNamesystem;
 import org.apache.hadoop.io.IOUtils;
+import org.apache.hadoop.ipc.RemoteException;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.StartupOption;
 import org.apache.hadoop.hdfs.server.namenode.NameNode;
 import org.apache.hadoop.hdfs.server.namenode.NameNodeAdapter;
+import org.apache.hadoop.hdfs.server.namenode.SafeModeException;
 import org.apache.hadoop.test.GenericTestUtils;
 
 import static org.junit.Assert.*;
@@ -372,4 +375,76 @@ public class TestSafeMode {
     dfs.setSafeMode(SafeModeAction.SAFEMODE_LEAVE);
     assertFalse("State was expected to be out of safemode.", dfs.isInSafeMode());
   }
+  
+  @Test
+  public void testSafeModeWhenZeroBlockLocations() throws IOException {
+
+    try {
+      Path file1 = new Path("/tmp/testManualSafeMode/file1");
+      Path file2 = new Path("/tmp/testManualSafeMode/file2");
+      
+      System.out.println("Created file1 and file2.");
+      
+      // create two files with one block each.
+      DFSTestUtil.createFile(fs, file1, 1000, (short)1, 0);
+      DFSTestUtil.createFile(fs, file2, 2000, (short)1, 0);
+      checkGetBlockLocationsWorks(fs, file1);
+      
+      NameNode namenode = cluster.getNameNode();
+
+      // manually set safemode.
+      dfs.setSafeMode(SafeModeAction.SAFEMODE_ENTER);
+      assertTrue("should still be in SafeMode", namenode.isInSafeMode());
+      // getBlock locations should still work since block locations exists
+      checkGetBlockLocationsWorks(fs, file1);
+      dfs.setSafeMode(SafeModeAction.SAFEMODE_LEAVE);
+      assertFalse("should not be in SafeMode", namenode.isInSafeMode());
+      
+      
+      // Now 2nd part of the tests where there aren't block locations
+      cluster.shutdownDataNodes();
+      cluster.shutdownNameNode(0);
+      
+      // now bring up just the NameNode.
+      cluster.restartNameNode();
+      cluster.waitActive();
+      
+      System.out.println("Restarted cluster with just the NameNode");
+      
+      namenode = cluster.getNameNode();
+      
+      assertTrue("No datanode is started. Should be in SafeMode", 
+                 namenode.isInSafeMode());
+      FileStatus stat = fs.getFileStatus(file1);
+      try {
+        fs.getFileBlockLocations(stat, 0, 1000);
+        assertTrue("Should have got safemode exception", false);
+      } catch (SafeModeException e) {
+        // as expected 
+      } catch (RemoteException re) {
+        if (!re.getClassName().equals(SafeModeException.class.getName()))
+          assertTrue("Should have got safemode exception", false);   
+      }
+
+
+      dfs.setSafeMode(SafeModeAction.SAFEMODE_LEAVE);      
+      assertFalse("Should not be in safemode", namenode.isInSafeMode());
+      checkGetBlockLocationsWorks(fs, file1);
+
+    } finally {
+      if(fs != null) fs.close();
+      if(cluster!= null) cluster.shutdown();
+    }
+  }
+  
+  void checkGetBlockLocationsWorks(FileSystem fs, Path fileName) throws IOException {
+    FileStatus stat = fs.getFileStatus(fileName);
+    try {  
+      fs.getFileBlockLocations(stat, 0, 1000);
+    } catch (SafeModeException e) {
+      assertTrue("Should have not got safemode exception", false);
+    } catch (RemoteException re) {
+      assertTrue("Should have not got safemode exception", false);   
+    }    
+  }
 }

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

@@ -56,7 +56,7 @@ public class NameNodeAdapter {
   public static LocatedBlocks getBlockLocations(NameNode namenode,
       String src, long offset, long length) throws IOException {
     return namenode.getNamesystem().getBlockLocations(
-        src, offset, length, false, true);
+        src, offset, length, false, true, true);
   }
   
   public static HdfsFileStatus getFileInfo(NameNode namenode, String src,