HDFS-4138. BackupNode startup fails due to uninitialized edit log. Contributed by Kihwal Lee.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1406743 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -1686,6 +1686,9 @@ Release 0.23.5 - UNRELEASED
     HDFS-3625. Fix TestBackupNode by properly initializing edit log during
     startup. (Junping Du via todd)
 
+    HDFS-4138. BackupNode startup fails due to uninitialized edit log.
+    (Kihwal Lee via shv)
+
 Release 0.23.4 - UNRELEASED
 
   INCOMPATIBLE CHANGES

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

@@ -77,10 +77,6 @@ public class BackupNode extends NameNode {
   String nnHttpAddress;
   /** Checkpoint manager */
   Checkpointer checkpointManager;
-  /** ClusterID to which BackupNode belongs to */
-  String clusterId;
-  /** Block pool Id of the peer namenode of this BackupNode */
-  String blockPoolId;
   
   BackupNode(Configuration conf, NamenodeRole role) throws IOException {
     super(conf, role);
@@ -144,6 +140,7 @@ public class BackupNode extends NameNode {
                  CommonConfigurationKeys.FS_TRASH_INTERVAL_DEFAULT);
     NamespaceInfo nsInfo = handshake(conf);
     super.initialize(conf);
+    namesystem.setBlockPoolId(nsInfo.getBlockPoolID());
 
     if (false == namesystem.isInSafeMode()) {
       namesystem.setSafeMode(SafeModeAction.SAFEMODE_ENTER);
@@ -153,9 +150,6 @@ public class BackupNode extends NameNode {
     // therefore lease hard limit should never expire.
     namesystem.leaseManager.setLeasePeriod(
         HdfsConstants.LEASE_SOFTLIMIT_PERIOD, Long.MAX_VALUE);
-    
-    clusterId = nsInfo.getClusterID();
-    blockPoolId = nsInfo.getBlockPoolID();
 
     // register with the active name-node 
     registerWith(nsInfo);
@@ -209,7 +203,7 @@ public class BackupNode extends NameNode {
   }
   
   /* @Override */// NameNode
-  public boolean setSafeMode(@SuppressWarnings("unused") SafeModeAction action)
+  public boolean setSafeMode(SafeModeAction action)
       throws IOException {
     throw new UnsupportedActionException("setSafeMode");
   }
@@ -405,14 +399,6 @@ public class BackupNode extends NameNode {
     return nsInfo;
   }
   
-  String getBlockPoolId() {
-    return blockPoolId;
-  }
-  
-  String getClusterId() {
-    return clusterId;
-  }
-  
   @Override
   protected NameNodeHAContext createHAContext() {
     return new BNHAContext();

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

@@ -3483,7 +3483,7 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
   @Metric({"TransactionsSinceLastLogRoll",
       "Number of transactions since last edit log roll"})
   public long getTransactionsSinceLastLogRoll() {
-    if (isInStandbyState()) {
+    if (isInStandbyState() || !getEditLog().isSegmentOpen()) {
       return 0;
     } else {
       return getEditLog().getLastWrittenTxId() -