/** Test that FSNamesystem#clear clears all leases. */
  @Test
  public void testFSNamespaceClearLeases() throws Exception {
    Configuration conf = new HdfsConfiguration();
    File nameDir = new File(MiniDFSCluster.getBaseDirectory(), "name");
    conf.set(DFS_NAMENODE_NAME_DIR_KEY, nameDir.getAbsolutePath());

    NameNode.initMetrics(conf, NamenodeRole.NAMENODE);
    DFSTestUtil.formatNameNode(conf);
    FSNamesystem fsn = FSNamesystem.loadFromDisk(conf);
    LeaseManager leaseMan = fsn.getLeaseManager();
    leaseMan.addLease("client1", "importantFile");
    assertEquals(1, leaseMan.countLease());
    fsn.clear();
    leaseMan = fsn.getLeaseManager();
    assertEquals(0, leaseMan.countLease());
  }
  @Test
  public void testReplQueuesActiveAfterStartupSafemode() throws IOException, InterruptedException {
    Configuration conf = new Configuration();

    FSEditLog fsEditLog = Mockito.mock(FSEditLog.class);
    FSImage fsImage = Mockito.mock(FSImage.class);
    Mockito.when(fsImage.getEditLog()).thenReturn(fsEditLog);

    FSNamesystem fsNamesystem = new FSNamesystem(conf, fsImage);
    FSNamesystem fsn = Mockito.spy(fsNamesystem);

    // Make shouldPopulaeReplQueues return true
    HAContext haContext = Mockito.mock(HAContext.class);
    HAState haState = Mockito.mock(HAState.class);
    Mockito.when(haContext.getState()).thenReturn(haState);
    Mockito.when(haState.shouldPopulateReplQueues()).thenReturn(true);
    Whitebox.setInternalState(fsn, "haContext", haContext);

    // Make NameNode.getNameNodeMetrics() not return null
    NameNode.initMetrics(conf, NamenodeRole.NAMENODE);

    fsn.enterSafeMode(false);
    assertTrue("FSNamesystem didn't enter safemode", fsn.isInSafeMode());
    assertTrue(
        "Replication queues were being populated during very first " + "safemode",
        !fsn.isPopulatingReplQueues());
    fsn.leaveSafeMode();
    assertTrue("FSNamesystem didn't leave safemode", !fsn.isInSafeMode());
    assertTrue(
        "Replication queues weren't being populated even after leaving " + "safemode",
        fsn.isPopulatingReplQueues());
    fsn.enterSafeMode(false);
    assertTrue("FSNamesystem didn't enter safemode", fsn.isInSafeMode());
    assertTrue(
        "Replication queues weren't being populated after entering " + "safemode 2nd time",
        fsn.isPopulatingReplQueues());
  }