HDFS-3438. BootstrapStandby should not require a rollEdits on active node. Contributed by Todd Lipcon.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1340343 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -190,6 +190,9 @@ Release 2.0.1-alpha - UNRELEASED
     HDFS-3440. More effectively limit stream memory consumption when reading
     corrupt edit logs (Colin Patrick McCabe via todd)
 
+    HDFS-3438. BootstrapStandby should not require a rollEdits on active node
+    (todd)
+
   OPTIMIZATIONS
 
   BUG FIXES

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/NamenodeProtocolServerSideTranslatorPB.java

@@ -32,6 +32,8 @@
 import org.apache.hadoop.hdfs.protocol.proto.NamenodeProtocolProtos.GetBlocksResponseProto;
 import org.apache.hadoop.hdfs.protocol.proto.NamenodeProtocolProtos.GetEditLogManifestRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.NamenodeProtocolProtos.GetEditLogManifestResponseProto;
+import org.apache.hadoop.hdfs.protocol.proto.NamenodeProtocolProtos.GetMostRecentCheckpointTxIdRequestProto;
+import org.apache.hadoop.hdfs.protocol.proto.NamenodeProtocolProtos.GetMostRecentCheckpointTxIdResponseProto;
 import org.apache.hadoop.hdfs.protocol.proto.NamenodeProtocolProtos.GetTransactionIdRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.NamenodeProtocolProtos.GetTransactionIdResponseProto;
 import org.apache.hadoop.hdfs.protocol.proto.NamenodeProtocolProtos.RegisterRequestProto;
@@ -105,6 +107,20 @@ public GetTransactionIdResponseProto getTransactionId(RpcController unused,
     return GetTransactionIdResponseProto.newBuilder().setTxId(txid).build();
   }
   
+  @Override
+  public GetMostRecentCheckpointTxIdResponseProto getMostRecentCheckpointTxId(
+      RpcController unused, GetMostRecentCheckpointTxIdRequestProto request)
+      throws ServiceException {
+    long txid;
+    try {
+      txid = impl.getMostRecentCheckpointTxId();
+    } catch (IOException e) {
+      throw new ServiceException(e);
+    }
+    return GetMostRecentCheckpointTxIdResponseProto.newBuilder().setTxId(txid).build();
+  }
+
+
   @Override
   public RollEditLogResponseProto rollEditLog(RpcController unused,
       RollEditLogRequestProto request) throws ServiceException {

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/NamenodeProtocolTranslatorPB.java

@@ -31,6 +31,7 @@
 import org.apache.hadoop.hdfs.protocol.proto.NamenodeProtocolProtos.GetBlockKeysRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.NamenodeProtocolProtos.GetBlocksRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.NamenodeProtocolProtos.GetEditLogManifestRequestProto;
+import org.apache.hadoop.hdfs.protocol.proto.NamenodeProtocolProtos.GetMostRecentCheckpointTxIdRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.NamenodeProtocolProtos.GetTransactionIdRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.NamenodeProtocolProtos.RegisterRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.NamenodeProtocolProtos.RollEditLogRequestProto;
@@ -119,6 +120,16 @@ public long getTransactionID() throws IOException {
     }
   }
 
+  @Override
+  public long getMostRecentCheckpointTxId() throws IOException {
+    try {
+      return rpcProxy.getMostRecentCheckpointTxId(NULL_CONTROLLER,
+          GetMostRecentCheckpointTxIdRequestProto.getDefaultInstance()).getTxId();
+    } catch (ServiceException e) {
+      throw ProtobufHelper.getRemoteException(e);
+    }
+  }
+
   @Override
   public CheckpointSignature rollEditLog() throws IOException {
     try {

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

@@ -50,7 +50,6 @@
 import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.DFSUtil;
 import org.apache.hadoop.hdfs.HDFSPolicyProvider;
-import org.apache.hadoop.hdfs.HdfsConfiguration;
 import org.apache.hadoop.hdfs.protocol.BlockListAsLongs;
 import org.apache.hadoop.hdfs.protocol.CorruptFileBlocks;
 import org.apache.hadoop.hdfs.protocol.DatanodeID;
@@ -712,8 +711,14 @@ public void refreshNodes() throws IOException {
 
   @Override // NamenodeProtocol
   public long getTransactionID() throws IOException {
-    namesystem.checkOperation(OperationCategory.CHECKPOINT);
+    namesystem.checkOperation(OperationCategory.UNCHECKED);
-    return namesystem.getEditLog().getSyncTxId();
+    return namesystem.getFSImage().getLastAppliedOrWrittenTxId();
+  }
+  
+  @Override // NamenodeProtocol
+  public long getMostRecentCheckpointTxId() throws IOException {
+    namesystem.checkOperation(OperationCategory.UNCHECKED);
+    return namesystem.getFSImage().getMostRecentCheckpointTxId();
   }
   
   @Override // NamenodeProtocol

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

@@ -33,16 +33,10 @@
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.conf.Configurable;
 import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.ha.HAServiceProtocol;
-import org.apache.hadoop.ha.HAServiceStatus;
-import org.apache.hadoop.ha.HAServiceProtocol.HAServiceState;
-import org.apache.hadoop.ha.ServiceFailedException;
 import org.apache.hadoop.hdfs.DFSUtil;
 import org.apache.hadoop.hdfs.HAUtil;
-import org.apache.hadoop.hdfs.HdfsConfiguration;
 import org.apache.hadoop.hdfs.NameNodeProxies;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
-import org.apache.hadoop.hdfs.server.namenode.CheckpointSignature;
 import org.apache.hadoop.hdfs.server.namenode.EditLogInputStream;
 import org.apache.hadoop.hdfs.server.namenode.FSImage;
 import org.apache.hadoop.hdfs.server.namenode.FSNamesystem;
@@ -52,10 +46,8 @@
 import org.apache.hadoop.hdfs.server.protocol.NamenodeProtocol;
 import org.apache.hadoop.hdfs.server.protocol.NamespaceInfo;
 import org.apache.hadoop.hdfs.tools.DFSHAAdmin;
-import org.apache.hadoop.hdfs.tools.NNHAServiceTarget;
 import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.io.MD5Hash;
-import org.apache.hadoop.security.AccessControlException;
 import org.apache.hadoop.security.SecurityUtil;
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.util.Tool;
@@ -90,7 +82,7 @@ public class BootstrapStandby implements Tool, Configurable {
   // Exit/return codes.
   static final int ERR_CODE_FAILED_CONNECT = 2;
   static final int ERR_CODE_INVALID_VERSION = 3;
-  static final int ERR_CODE_OTHER_NN_NOT_ACTIVE = 4;
+  // Skip 4 - was used in previous versions, but no longer returned.
   static final int ERR_CODE_ALREADY_FORMATTED = 5;
   static final int ERR_CODE_LOGS_UNAVAILABLE = 6; 
 
@@ -142,12 +134,6 @@ private NamenodeProtocol createNNProtocolProxy()
         .getProxy();
   }
   
-  private HAServiceProtocol createHAProtocolProxy()
-      throws IOException {
-    return new NNHAServiceTarget(new HdfsConfiguration(conf), nsId, otherNNId)
-        .getProxy(conf, 15000);
-  }
-
   private int doRun() throws IOException {
 
     NamenodeProtocol proxy = createNNProtocolProxy();
@@ -184,29 +170,6 @@ private int doRun() throws IOException {
         "           Layout version: " + nsInfo.getLayoutVersion() + "\n" +
         "=====================================================");
 
-    // Ensure the other NN is active - we can't force it to roll edit logs
-    // below if it's not active.
-    if (!isOtherNNActive()) {
-      String err = "NameNode " + nsId + "." + nnId + " at " + otherIpcAddr +
-          " is not currently in ACTIVE state.";
-      if (!interactive) {
-        LOG.fatal(err + " Please transition it to " +
-            "active before attempting to bootstrap a standby node.");
-        return ERR_CODE_OTHER_NN_NOT_ACTIVE;
-      }
-      
-      System.err.println(err);
-      if (ToolRunner.confirmPrompt(
-            "Do you want to automatically transition it to active now?")) {
-        transitionOtherNNActive();
-      } else {
-        LOG.fatal("User aborted. Exiting without bootstrapping standby.");
-        return ERR_CODE_OTHER_NN_NOT_ACTIVE;
-      }
-    }
-    
-
-    
     // Check with the user before blowing away data.
     if (!NameNode.confirmFormat(
             Sets.union(Sets.newHashSet(dirsToFormat),
@@ -215,11 +178,8 @@ private int doRun() throws IOException {
       return ERR_CODE_ALREADY_FORMATTED;
     }
     
-    // Force the active to roll its log
+    long imageTxId = proxy.getMostRecentCheckpointTxId();
-    CheckpointSignature csig = proxy.rollEditLog();
+    long curTxId = proxy.getTransactionID();
-    long imageTxId = csig.getMostRecentCheckpointTxId();
-    long rollTxId = csig.getCurSegmentTxId();
-
     
     // Format the storage (writes VERSION file)
     NNStorage storage = new NNStorage(conf, dirsToFormat, editUrisToFormat);
@@ -233,11 +193,11 @@ private int doRun() throws IOException {
     
     // Ensure that we have enough edits already in the shared directory to
     // start up from the last checkpoint on the active.
-    if (!checkLogsAvailableForRead(image, imageTxId, rollTxId)) {
+    if (!checkLogsAvailableForRead(image, imageTxId, curTxId)) {
       return ERR_CODE_LOGS_UNAVAILABLE;
     }
     
-    image.getStorage().writeTransactionIdFileToStorage(rollTxId);
+    image.getStorage().writeTransactionIdFileToStorage(curTxId);
 
     // Download that checkpoint into our storage directories.
     MD5Hash hash = TransferFsImage.downloadImageToStorage(
@@ -248,31 +208,31 @@ private int doRun() throws IOException {
   }
 
   
-  private void transitionOtherNNActive()
-      throws AccessControlException, ServiceFailedException, IOException {
-    LOG.info("Transitioning the running namenode to active...");
-    createHAProtocolProxy().transitionToActive();    
-    LOG.info("Successful");
-  }
-
   private boolean checkLogsAvailableForRead(FSImage image, long imageTxId,
-      long rollTxId) {
+      long curTxIdOnOtherNode) {
 
+    if (imageTxId == curTxIdOnOtherNode) {
+      // The other node hasn't written any logs since the last checkpoint.
+      // This can be the case if the NN was freshly formatted as HA, and
+      // then started in standby mode, so it has no edit logs at all.
+      return true;
+    }
     long firstTxIdInLogs = imageTxId + 1;
-    long lastTxIdInLogs = rollTxId - 1;
+    
-    assert lastTxIdInLogs >= firstTxIdInLogs;
+    assert curTxIdOnOtherNode >= firstTxIdInLogs :
+      "first=" + firstTxIdInLogs + " onOtherNode=" + curTxIdOnOtherNode;
     
     try {
       Collection<EditLogInputStream> streams =
         image.getEditLog().selectInputStreams(
-          firstTxIdInLogs, lastTxIdInLogs, false);
+          firstTxIdInLogs, curTxIdOnOtherNode, true);
       for (EditLogInputStream stream : streams) {
         IOUtils.closeStream(stream);
       }
       return true;
     } catch (IOException e) {
       String msg = "Unable to read transaction ids " +
-          firstTxIdInLogs + "-" + lastTxIdInLogs +
+          firstTxIdInLogs + "-" + curTxIdOnOtherNode +
           " from the configured shared edits storage " +
           Joiner.on(",").join(sharedEditsUris) + ". " +
           "Please copy these logs into the shared edits storage " + 
@@ -291,12 +251,6 @@ private boolean checkLayoutVersion(NamespaceInfo nsInfo) throws IOException {
     return (nsInfo.getLayoutVersion() == HdfsConstants.LAYOUT_VERSION);
   }
   
-  private boolean isOtherNNActive()
-      throws AccessControlException, IOException {
-    HAServiceStatus status = createHAProtocolProxy().getServiceStatus();
-    return status.getState() == HAServiceState.ACTIVE;
-  }
-
   private void parseConfAndFindOtherNN() throws IOException {
     Configuration conf = getConf();
     nsId = DFSUtil.getNamenodeNameServiceId(conf);

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/protocol/NamenodeProtocol.java

@@ -87,11 +87,17 @@ public BlocksWithLocations getBlocks(DatanodeInfo datanode, long size)
 
   /**
    * @return The most recent transaction ID that has been synced to
-   * persistent storage.
+   * persistent storage, or applied from persistent storage in the
+   * case of a non-active node.
    * @throws IOException
    */
   public long getTransactionID() throws IOException;
 
+  /**
+   * Get the transaction ID of the most recent checkpoint.
+   */
+  public long getMostRecentCheckpointTxId() throws IOException;
+
   /**
    * Closes the current edit log and opens a new one. The 
    * call fails if the file system is in SafeMode.

hadoop-hdfs-project/hadoop-hdfs/src/main/proto/NamenodeProtocol.proto

@@ -84,6 +84,16 @@ message RollEditLogResponseProto {
   required CheckpointSignatureProto signature = 1;
 }
 
+/**
+ * void request
+ */
+message GetMostRecentCheckpointTxIdRequestProto {
+}
+
+message GetMostRecentCheckpointTxIdResponseProto{
+  required uint64 txId = 1;
+}
+
 /**
  * registration - Namenode reporting the error
  * errorCode - error code indicating the error
@@ -188,13 +198,19 @@ service NamenodeProtocolService {
   rpc getTransactionId(GetTransactionIdRequestProto) 
       returns(GetTransactionIdResponseProto);
 
+  /**
+   * Get the transaction ID of the most recently persisted editlog record
+   */
+  rpc getMostRecentCheckpointTxId(GetMostRecentCheckpointTxIdRequestProto) 
+      returns(GetMostRecentCheckpointTxIdResponseProto);
+
   /**
    * Close the current editlog and open a new one for checkpointing purposes
    */
   rpc rollEditLog(RollEditLogRequestProto) returns(RollEditLogResponseProto);
 
   /**
-   * Close the current editlog and open a new one for checkpointing purposes
+   * Request info about the version running on this NameNode
    */
   rpc versionRequest(VersionRequestProto) returns(VersionResponseProto);
 

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

@@ -23,6 +23,7 @@
 import java.net.URI;
 import java.util.Collections;
 import java.util.List;
+import java.util.Set;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -35,6 +36,7 @@
 import org.apache.hadoop.hdfs.server.namenode.NNStorage;
 import org.apache.hadoop.hdfs.server.namenode.NameNode;
 import org.apache.hadoop.hdfs.server.namenode.NameNodeAdapter;
+import org.apache.hadoop.hdfs.server.namenode.NamenodeFsck;
 import org.apache.hadoop.test.GenericTestUtils;
 import org.apache.hadoop.test.GenericTestUtils.LogCapturer;
 import org.junit.After;
@@ -43,6 +45,7 @@
 
 import com.google.common.base.Suppliers;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Lists;
 
 import static org.junit.Assert.*;
@@ -177,7 +180,7 @@ public void testSharedEditsMissingLogs() throws Exception {
       logs.stopCapturing();
     }
     GenericTestUtils.assertMatches(logs.getOutput(),
-        "FATAL.*Unable to read transaction ids 1-4 from the configured shared");
+        "FATAL.*Unable to read transaction ids 1-3 from the configured shared");
   }
   
   @Test
@@ -195,30 +198,29 @@ public void testStandbyDirsAlreadyExist() throws Exception {
     assertEquals(0, rc);
   }
   
+  /**
+   * Test that, even if the other node is not active, we are able
+   * to bootstrap standby from it.
+   */
   @Test(timeout=30000)
   public void testOtherNodeNotActive() throws Exception {
     cluster.transitionToStandby(0);
     int rc = BootstrapStandby.run(
-        new String[]{"-nonInteractive"},
-        cluster.getConfiguration(1));
-    assertEquals(BootstrapStandby.ERR_CODE_OTHER_NN_NOT_ACTIVE, rc);
-    
-    // Answer "yes" to the prompt about transition to active
-    System.setIn(new ByteArrayInputStream("yes\n".getBytes()));
-    rc = BootstrapStandby.run(
         new String[]{"-force"},
         cluster.getConfiguration(1));
     assertEquals(0, rc);
-    
-    assertFalse(nn0.getNamesystem().isInStandbyState());
   }
   
   private void assertNNFilesMatch() throws Exception {
     List<File> curDirs = Lists.newArrayList();
     curDirs.addAll(FSImageTestUtil.getNameNodeCurrentDirs(cluster, 0));
     curDirs.addAll(FSImageTestUtil.getNameNodeCurrentDirs(cluster, 1));
+    
+    // Ignore seen_txid file, since the newly bootstrapped standby
+    // will have a higher seen_txid than the one it bootstrapped from.
+    Set<String> ignoredFiles = ImmutableSet.of("seen_txid");
     FSImageTestUtil.assertParallelFilesAreIdentical(curDirs,
-        Collections.<String>emptySet());
+        ignoredFiles);
   }
 
   private void removeStandbyNameDirs() {