HDFS-14500. NameNode StartupProgress should not allow new steps in an already-completed phase. Contributed by Erik Krogen.

(cherry-picked from 55e0c134f0)
(cherry-picked from c26cf22d6b)

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

@@ -84,13 +84,14 @@ public class StartupProgress {
   }
 
   /**
-   * Begins execution of the specified step within the specified phase.
+   * Begins execution of the specified step within the specified phase. This is
+   * a no-op if the phase is already completed.
    * 
-   * @param phase Phase to begin
+   * @param phase Phase within which the step should be started
    * @param step Step to begin
    */
   public void beginStep(Phase phase, Step step) {
-    if (!isComplete()) {
+    if (!isComplete(phase)) {
       lazyInitStep(phase, step).beginTime = monotonicNow();
     }
   }
@@ -107,13 +108,14 @@ public class StartupProgress {
   }
 
   /**
-   * Ends execution of the specified step within the specified phase.
+   * Ends execution of the specified step within the specified phase. This is
+   * a no-op if the phase is already completed.
    *
-   * @param phase Phase to end
+   * @param phase Phase within which the step should be ended
    * @param step Step to end
    */
   public void endStep(Phase phase, Step step) {
-    if (!isComplete()) {
+    if (!isComplete(phase)) {
       lazyInitStep(phase, step).endTime = monotonicNow();
     }
   }
@@ -149,7 +151,7 @@ public class StartupProgress {
    * @return Counter associated with phase and step
    */
   public Counter getCounter(Phase phase, Step step) {
-    if (!isComplete()) {
+    if (!isComplete(phase)) {
       final StepTracking tracking = lazyInitStep(phase, step);
       return new Counter() {
         @Override
@@ -242,12 +244,17 @@ public class StartupProgress {
    * @return boolean true if the entire startup process has completed
    */
   private boolean isComplete() {
-    for (Phase phase: EnumSet.allOf(Phase.class)) {
+    return EnumSet.allOf(Phase.class).stream().allMatch(this::isComplete);
-      if (getStatus(phase) != Status.COMPLETE) {
-        return false;
   }
-    }
+
-    return true;
+  /**
+   * Returns true if the given startup phase has been completed.
+   *
+   * @param phase Which phase to check for completion
+   * @return boolean true if the given startup phase has completed.
+   */
+  private boolean isComplete(Phase phase) {
+    return getStatus(phase) == Status.COMPLETE;
   }
 
   /**

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

@@ -159,6 +159,14 @@ public class TestStartupProgress {
     startupProgress.endStep(LOADING_FSIMAGE, step);
     startupProgress.endPhase(LOADING_FSIMAGE);
 
+    StartupProgressView beforePhaseUpdate = startupProgress.createView();
+
+    // LOADING_FSIMAGE phase has been completed, but attempt more updates to it
+    Step fsimageStep2 = new Step(INODES);
+    startupProgress.beginStep(LOADING_FSIMAGE, fsimageStep2);
+    incrementCounter(startupProgress, LOADING_FSIMAGE, fsimageStep2, 1000000L);
+    startupProgress.endStep(LOADING_FSIMAGE, fsimageStep2);
+
     // Force completion of phases, so that entire startup process is completed.
     for (Phase phase: EnumSet.allOf(Phase.class)) {
       if (startupProgress.getStatus(phase) != Status.COMPLETE) {
@@ -191,26 +199,39 @@ public class TestStartupProgress {
 
     // Expect that data was frozen after completion of entire startup process, so
     // second set of updates and counter increments should have had no effect.
-    assertEquals(before.getCount(LOADING_FSIMAGE),
+    assertViewEquals(before, after, LOADING_FSIMAGE, step, fsimageStep2);
-      after.getCount(LOADING_FSIMAGE));
-    assertEquals(before.getCount(LOADING_FSIMAGE, step),
-      after.getCount(LOADING_FSIMAGE, step));
     assertEquals(before.getElapsedTime(), after.getElapsedTime());
-    assertEquals(before.getElapsedTime(LOADING_FSIMAGE),
+
-      after.getElapsedTime(LOADING_FSIMAGE));
+    // After the phase was completed but before startup was completed,
-    assertEquals(before.getElapsedTime(LOADING_FSIMAGE, step),
+    // everything should be equal, except for the total elapsed time
-      after.getElapsedTime(LOADING_FSIMAGE, step));
+    assertViewEquals(beforePhaseUpdate, after, LOADING_FSIMAGE,
-    assertEquals(before.getFile(LOADING_FSIMAGE),
+        step, fsimageStep2);
-      after.getFile(LOADING_FSIMAGE));
+
-    assertEquals(before.getSize(LOADING_FSIMAGE),
-      after.getSize(LOADING_FSIMAGE));
-    assertEquals(before.getTotal(LOADING_FSIMAGE),
-      after.getTotal(LOADING_FSIMAGE));
-    assertEquals(before.getTotal(LOADING_FSIMAGE, step),
-      after.getTotal(LOADING_FSIMAGE, step));
     assertFalse(after.getSteps(LOADING_EDITS).iterator().hasNext());
   }
 
+  private void assertViewEquals(StartupProgressView view1,
+      StartupProgressView view2, Phase phaseToVerify, Step... stepsToVerify) {
+    assertEquals(view1.getCount(phaseToVerify),
+        view2.getCount(phaseToVerify));
+    assertEquals(view1.getElapsedTime(phaseToVerify),
+        view2.getElapsedTime(phaseToVerify));
+    assertEquals(view1.getFile(phaseToVerify),
+        view2.getFile(phaseToVerify));
+    assertEquals(view1.getSize(phaseToVerify),
+        view2.getSize(phaseToVerify));
+    assertEquals(view1.getTotal(phaseToVerify),
+        view2.getTotal(phaseToVerify));
+    for (Step step : stepsToVerify) {
+      assertEquals(view1.getCount(phaseToVerify, step),
+          view2.getCount(phaseToVerify, step));
+      assertEquals(view1.getElapsedTime(phaseToVerify, step),
+          view2.getElapsedTime(phaseToVerify, step));
+      assertEquals(view1.getTotal(phaseToVerify, step),
+          view2.getTotal(phaseToVerify, step));
+    }
+  }
+
   @Test(timeout=10000)
   public void testInitialState() {
     StartupProgressView view = startupProgress.createView();
@@ -375,7 +396,6 @@ public class TestStartupProgress {
             startupProgress.setTotal(phase, step, total);
             incrementCounter(startupProgress, phase, step, 100L);
             startupProgress.endStep(phase, step);
-            startupProgress.endPhase(phase);
             return null;
           }
         });
@@ -384,6 +404,11 @@ public class TestStartupProgress {
       exec.shutdown();
       assertTrue(exec.awaitTermination(10000L, TimeUnit.MILLISECONDS));
     }
+    // Once a phase ends, future modifications to the steps in that phase are
+    // ignored. Thus do not end the phases until after the other ops are done.
+    for (Phase phase : phases) {
+      startupProgress.endPhase(phase);
+    }
 
     StartupProgressView view = startupProgress.createView();
     assertNotNull(view);