HDFS-10192. Namenode safemode not coming out during failover. Contributed by Brahma Reddy Battula.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockManager.java

@@ -1974,7 +1974,7 @@ public class BlockManager implements BlockStatsMXBean {
     return bmSafeMode.leaveSafeMode(force);
   }
 
-  void checkSafeMode() {
+  public void checkSafeMode() {
     bmSafeMode.checkSafeMode();
   }
 

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

@@ -1154,6 +1154,7 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
       }
     } finally {
       startingActiveService = false;
+      blockManager.checkSafeMode();
       writeUnlock();
     }
   }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestBlockManagerSafeMode.java

@@ -66,6 +66,7 @@ public class TestBlockManagerSafeMode {
   private static final long BLOCK_THRESHOLD = (long)(BLOCK_TOTAL * THRESHOLD);
   private static final int EXTENSION = 1000; // 1 second
 
+  private FSNamesystem fsn;
   private BlockManager bm;
   private DatanodeManager dn;
   private BlockManagerSafeMode bmSafeMode;
@@ -90,7 +91,7 @@ public class TestBlockManagerSafeMode {
     conf.setInt(DFSConfigKeys.DFS_NAMENODE_SAFEMODE_MIN_DATANODES_KEY,
         DATANODE_NUM);
 
-    FSNamesystem fsn = mock(FSNamesystem.class);
+    fsn = mock(FSNamesystem.class);
     doReturn(true).when(fsn).hasWriteLock();
     doReturn(true).when(fsn).hasReadLock();
     doReturn(true).when(fsn).isRunning();
@@ -163,6 +164,17 @@ public class TestBlockManagerSafeMode {
     setBlockSafe(BLOCK_THRESHOLD);
     bmSafeMode.checkSafeMode();
     assertEquals(BMSafeModeStatus.EXTENSION, getSafeModeStatus());
+
+    // should stay in PENDING_THRESHOLD during transitionToActive
+    doReturn(true).when(fsn).inTransitionToActive();
+    Whitebox.setInternalState(bmSafeMode, "extension", 0);
+    setSafeModeStatus(BMSafeModeStatus.PENDING_THRESHOLD);
+    setBlockSafe(BLOCK_THRESHOLD);
+    bmSafeMode.checkSafeMode();
+    assertEquals(BMSafeModeStatus.PENDING_THRESHOLD, getSafeModeStatus());
+    doReturn(false).when(fsn).inTransitionToActive();
+    bmSafeMode.checkSafeMode();
+    assertEquals(BMSafeModeStatus.OFF, getSafeModeStatus());
   }
 
   /**

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

@@ -851,4 +851,39 @@ public class TestHASafeMode {
       cluster.shutdown();
     }
   }
+
+  @Test(timeout = 60000)
+  public void testSafeModeExitAfterTransition() throws Exception {
+    DFSTestUtil.createFile(fs, new Path("/test"), 5 * BLOCK_SIZE, (short) 3,
+        1L);
+    banner("Stopping standby");
+    cluster.shutdownNameNode(1);
+    DFSTestUtil.createFile(fs, new Path("/test2"), 3 * BLOCK_SIZE, (short) 3,
+        1L);
+    // Roll edit logs to be read by standby
+    nn0.getRpcServer().rollEditLog();
+    fs.delete(new Path("/test"), true);
+    // Wait till the blocks are deleted from all DNs
+    GenericTestUtils.waitFor(new Supplier<Boolean>() {
+      @Override
+      public Boolean get() {
+        return cluster.getNamesystem(0).getBlockManager()
+            .getPendingDeletionBlocksCount() == 0;
+      }
+    }, 1000, 10000);
+    restartStandby();
+    // Wait till all the datanodes are registered.
+    GenericTestUtils.waitFor(new Supplier<Boolean>() {
+      @Override
+      public Boolean get() {
+        return cluster.getNamesystem(1).getNumLiveDataNodes() == 3;
+      }
+    }, 1000, 10000);
+    cluster.triggerBlockReports();
+    NameNodeAdapter.abortEditLogs(nn0);
+    cluster.shutdownNameNode(0);
+    banner(nn1.getNamesystem().getSafemode());
+    cluster.transitionToActive(1);
+    assertSafeMode(nn1, 3, 3, 3, 0);
+  }
 }