HDFS-2285. Merge r1195013 from trunk to 0.23

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1298183 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -164,6 +164,9 @@ Release 0.23.3 - UNRELEASED
     HDFS-1765. Block Replication should respect under-replication
     block priority. (Uma Maheswara Rao G via eli)
 
+    HDFS-2285. BackupNode should reject requests to modify namespace.
+    (shv and Uma Maheswara Rao)
+
 Release 0.23.2 - UNRELEASED
 
   INCOMPATIBLE CHANGES

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

@@ -28,6 +28,7 @@ import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.DFSUtil;
 import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
+import org.apache.hadoop.hdfs.protocol.HdfsConstants.SafeModeAction;
 import org.apache.hadoop.hdfs.protocol.proto.JournalProtocolProtos.JournalProtocolService;
 import org.apache.hadoop.hdfs.protocolPB.JournalProtocolPB;
 import org.apache.hadoop.hdfs.protocolPB.JournalProtocolServerSideTranslatorPB;
@@ -142,6 +143,10 @@ public class BackupNode extends NameNode {
                  CommonConfigurationKeys.FS_TRASH_INTERVAL_DEFAULT);
     NamespaceInfo nsInfo = handshake(conf);
     super.initialize(conf);
+    if (false == namesystem.isInSafeMode()) {
+      namesystem.setSafeMode(SafeModeAction.SAFEMODE_ENTER);
+    }
+
     // Backup node should never do lease recovery,
     // therefore lease hard limit should never expire.
     namesystem.leaseManager.setLeasePeriod(
@@ -196,6 +201,11 @@ public class BackupNode extends NameNode {
     super.stop();
   }
   
+  /* @Override */// NameNode
+  public boolean setSafeMode(SafeModeAction action) throws IOException {
+    throw new UnsupportedActionException("setSafeMode");
+  }
+  
   static class BackupNodeRpcServer extends NameNodeRpcServer implements
       JournalProtocol {
     private final String nnRpcAddress;

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

@@ -242,6 +242,10 @@ class Checkpointer extends Daemon {
     }
     
     long txid = bnImage.getLastAppliedTxId();
+    
+    backupNode.namesystem.dir.setReady();
+    backupNode.namesystem.setBlockTotal();
+    
     bnImage.saveFSImageInAllDirs(backupNode.getNamesystem(), txid);
     bnStorage.writeAll();
 

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

@@ -159,6 +159,11 @@ public class FSDirectory implements Closeable {
    */
   void imageLoadComplete() {
     Preconditions.checkState(!ready, "FSDirectory already loaded");
+    setReady();
+  }
+
+  void setReady() {
+    if(ready) return;
     writeLock();
     try {
       setReady(true);

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

@@ -3375,7 +3375,7 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
   /**
    * Set the total number of blocks in the system. 
    */
-  private void setBlockTotal() {
+  void setBlockTotal() {
     // safeMode is volatile, and may be set to null at any time
     SafeModeInfo safeMode = this.safeMode;
     if (safeMode == null)

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

@@ -21,9 +21,12 @@ import static org.junit.Assert.*;
 
 import java.io.File;
 import java.io.IOException;
+import java.net.InetSocketAddress;
 import java.util.Collections;
 import java.util.List;
 
+import junit.framework.TestCase;
+
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.commons.logging.impl.Log4JLogger;
@@ -31,13 +34,13 @@ import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.FileUtil;
 import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.HdfsConfiguration;
 import org.apache.hadoop.hdfs.MiniDFSCluster;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.StartupOption;
 import org.apache.hadoop.hdfs.server.common.Storage.StorageDirectory;
 import org.apache.hadoop.hdfs.server.namenode.FileJournalManager.EditLogFile;
 import org.apache.hadoop.hdfs.server.protocol.NamenodeProtocols;
-import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.test.GenericTestUtils;
 import org.apache.log4j.Level;
 import org.junit.Before;
@@ -244,8 +247,11 @@ public class TestBackupNode {
   void testCheckpoint(StartupOption op) throws Exception {
     Path file1 = new Path("checkpoint.dat");
     Path file2 = new Path("checkpoint2.dat");
+    Path file3 = new Path("backup.dat");
 
     Configuration conf = new HdfsConfiguration();
+    short replication = (short)conf.getInt("dfs.replication", 3);
+    int numDatanodes = Math.max(3, replication);
     conf.set(DFSConfigKeys.DFS_BLOCKREPORT_INITIAL_DELAY_KEY, "0");
     conf.setInt(DFSConfigKeys.DFS_DATANODE_SCAN_PERIOD_HOURS_KEY, -1); // disable block scanner
     conf.setInt(DFSConfigKeys.DFS_NAMENODE_CHECKPOINT_TXNS_KEY, 1);
@@ -293,7 +299,7 @@ public class TestBackupNode {
       //
       // Restart cluster and verify that file1 still exist.
       //
-      cluster = new MiniDFSCluster.Builder(conf).numDataNodes(0)
+      cluster = new MiniDFSCluster.Builder(conf).numDataNodes(numDatanodes)
                                                 .format(false).build();
       fileSys = cluster.getFileSystem();
       // check that file1 still exists
@@ -322,6 +328,26 @@ public class TestBackupNode {
       backup.doCheckpoint();
       waitCheckpointDone(cluster, txid);
 
+      // Try BackupNode operations
+      InetSocketAddress add = backup.getNameNodeAddress();
+      // Write to BN
+      FileSystem bnFS = FileSystem.get(new Path("hdfs://"
+          + NameNode.getHostPortString(add)).toUri(), conf);
+      boolean canWrite = true;
+      try {
+        TestCheckpoint.writeFile(bnFS, file3, replication);
+      } catch (IOException eio) {
+        LOG.info("Write to BN failed as expected: ", eio);
+        canWrite = false;
+      }
+      assertFalse("Write to BackupNode must be prohibited.", canWrite);
+
+      TestCheckpoint.writeFile(fileSys, file3, replication);
+      TestCheckpoint.checkFile(fileSys, file3, replication);
+      // should also be on BN right away
+      assertTrue("file3 does not exist on BackupNode",
+          op != StartupOption.BACKUP || bnFS.exists(file3));
+
     } catch(IOException e) {
       LOG.error("Error in TestBackupNode:", e);
       assertTrue(e.getLocalizedMessage(), false);