Add Ut for test lastCheckpointTime

Author: eddy.cao

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

@@ -69,7 +69,7 @@ public class StandbyCheckpointer {
   private final CheckpointConf checkpointConf;
   private final Configuration conf;
   private final FSNamesystem namesystem;
-  private long lastCheckpointTime;
+  private static long lastCheckpointTime;
   private final CheckpointerThread thread;
   private final ThreadFactory uploadThreadFactory;
   private List<URL> activeNNAddresses;
@@ -375,6 +375,11 @@ static int getCanceledCount() {
     return canceledCount;
   }
 
+  @VisibleForTesting
+  static long getLastCheckpointTime() {
+    return lastCheckpointTime;
+  }
+
   private long countUncheckpointedTxns() {
     FSImage img = namesystem.getFSImage();
     return img.getCorrectLastAppliedOrWrittenTxId() -

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

@@ -649,6 +649,50 @@ public void testCheckpointSucceedsWithLegacyOIVException() throws Exception {
     HATestUtil.waitForCheckpoint(cluster, 0, ImmutableList.of(12));
   }
 
+  /**
+   * Test that lastCheckpointTime is correctly updated at each checkpoint
+   */
+  @Test(timeout = 300000)
+  public void testLastCheckpointTime()
+      throws Exception {
+    for (int i = 1; i < NUM_NNS; i++) {
+      cluster.shutdownNameNode(i);
+
+      // Make true checkpoint for DFS_NAMENODE_CHECKPOINT_PERIOD_KEY
+      cluster.getConfiguration(i).setInt(
+          DFSConfigKeys.DFS_NAMENODE_CHECKPOINT_PERIOD_KEY, 3);
+      cluster.getConfiguration(i).setInt(
+          DFSConfigKeys.DFS_NAMENODE_CHECKPOINT_TXNS_KEY, 1000);
+    }
+
+    doEdits(0, 10);
+    cluster.transitionToStandby(0);
+
+    // Standby NNs do checkpoint without active NN available.
+    for (int i = 1; i < NUM_NNS; i++) {
+      cluster.restartNameNode(i, false);
+    }
+    cluster.waitClusterUp();
+
+    cluster.transitionToActive(0);
+    cluster.transitionToStandby(1);
+
+    HATestUtil.waitForCheckpoint(cluster, 1, ImmutableList.of(12));
+    Thread.sleep(3000);
+
+    // Wait for 2 seconds to expire last upload time.
+    Long lastCheckpointTime1 = StandbyCheckpointer.getLastCheckpointTime();
+
+    doEdits(11, 20);
+    nns[0].getRpcServer().rollEditLog();
+
+    HATestUtil.waitForCheckpoint(cluster, 1, ImmutableList.of(23));
+    Thread.sleep(3000);
+    Long lastCheckpointTime2 = StandbyCheckpointer.getLastCheckpointTime();
+    // Make sure the interv
+    assertTrue(lastCheckpointTime2 - lastCheckpointTime1 > 3000);
+  }
+
   private void doEdits(int start, int stop) throws IOException {
     for (int i = start; i < stop; i++) {
       Path p = new Path("/test" + i);