/**
   * Test interruptable while blocking wait on root and meta.
   *
   * @throws IOException
   * @throws InterruptedException
   */
  @Test
  public void testInterruptWaitOnMetaAndRoot() throws IOException, InterruptedException {
    HRegionInterface implementation = Mockito.mock(HRegionInterface.class);
    HConnection connection = mockConnection(implementation);

    final CatalogTracker ct = constructAndStartCatalogTracker(connection);
    ServerName hsa = ct.getRootLocation();
    Assert.assertNull(hsa);
    ServerName meta = ct.getMetaLocation();
    Assert.assertNull(meta);
    Thread t =
        new Thread() {
          @Override
          public void run() {
            try {
              ct.waitForMeta();
            } catch (InterruptedException e) {
              throw new RuntimeException("Interrupted", e);
            }
          }
        };
    t.start();
    while (!t.isAlive()) Threads.sleep(1);
    Threads.sleep(1);
    assertTrue(t.isAlive());
    ct.stop();
    // Join the thread... should exit shortly.
    t.join();
  }
  /**
   * Test waiting on meta w/ no timeout specified.
   *
   * @throws Exception
   */
  @Ignore // Can't make it work reliably on all platforms; mockito gets confused
  // Throwing: org.mockito.exceptions.misusing.WrongTypeOfReturnValue:
  // Result cannot be returned by locateRegion()
  // If you plug locateRegion, it then throws for incCounter, and if you plug
  // that ... and so one.
  @Test
  public void testNoTimeoutWaitForMeta() throws Exception {
    // Mock an HConnection and a HRegionInterface implementation.  Have the
    // HConnection return the HRI.  Have the HRI return a few mocked up responses
    // to make our test work.
    // Mock an HRegionInterface.
    final HRegionInterface implementation = Mockito.mock(HRegionInterface.class);
    HConnection connection = mockConnection(implementation);

    // Now the ct is up... set into the mocks some answers that make it look
    // like things have been getting assigned. Make it so we'll return a
    // location (no matter what the Get is). Same for getHRegionInfo -- always
    // just return the meta region.
    final Result result = getMetaTableRowResult();

    // TODO: Refactor.  This method has been moved out of HConnection.
    // It works for now but has been deprecated.
    Mockito.when(connection.getRegionServerWithRetries((ServerCallable<Result>) Mockito.any()))
        .thenReturn(result);
    Mockito.when(implementation.getRegionInfo((byte[]) Mockito.any()))
        .thenReturn(HRegionInfo.FIRST_META_REGIONINFO);
    final CatalogTracker ct = constructAndStartCatalogTracker(connection);
    ServerName hsa = ct.getMetaLocation();
    Assert.assertNull(hsa);

    // Now test waiting on meta location getting set.
    Thread t =
        new WaitOnMetaThread(ct) {
          @Override
          void doWaiting() throws InterruptedException {
            this.ct.waitForMeta();
          }
        };
    startWaitAliveThenWaitItLives(t, 1000);

    // This should trigger wake up of meta wait (Its the removal of the meta
    // region unassigned node that triggers catalogtrackers that a meta has
    // been assigned).
    String node = ct.getMetaNodeTracker().getNode();
    ZKUtil.createAndFailSilent(this.watcher, node);
    MetaEditor.updateMetaLocation(ct, HRegionInfo.FIRST_META_REGIONINFO, SN);
    ZKUtil.deleteNode(this.watcher, node);
    // Go get the new meta location. waitForMeta gets and verifies meta.
    Assert.assertTrue(ct.waitForMeta(10000).equals(SN));
    // Join the thread... should exit shortly.
    t.join();
    // Now meta is available.
    Assert.assertTrue(ct.waitForMeta(10000).equals(SN));
  }
  /**
   * Test waiting on root w/ no timeout specified.
   *
   * @throws IOException
   * @throws InterruptedException
   * @throws KeeperException
   */
  @Test
  public void testNoTimeoutWaitForRoot() throws IOException, InterruptedException, KeeperException {
    HConnection connection = Mockito.mock(HConnection.class);
    final CatalogTracker ct = constructAndStartCatalogTracker(connection);
    ServerName hsa = ct.getRootLocation();
    Assert.assertNull(hsa);

    // Now test waiting on root location getting set.
    Thread t = new WaitOnMetaThread(ct);
    startWaitAliveThenWaitItLives(t, 1000);
    // Set a root location.
    hsa = setRootLocation();
    // Join the thread... should exit shortly.
    t.join();
    // Now root is available.
    Assert.assertTrue(ct.getRootLocation().equals(hsa));
  }
  /**
   * Test for HBASE-4288. Throw an IOE when trying to verify meta region and prove it doesn't cause
   * master shutdown.
   *
   * @see <a href="https://issues.apache.org/jira/browse/HBASE-4288">HBASE-4288</a>
   * @throws IOException
   * @throws InterruptedException
   * @throws KeeperException
   */
  @Test
  public void testServerNotRunningIOException()
      throws IOException, InterruptedException, KeeperException {
    // Mock an HRegionInterface.
    final HRegionInterface implementation = Mockito.mock(HRegionInterface.class);
    HConnection connection = mockConnection(implementation);

    // If a 'getRegionInfo' is called on mocked HRegionInterface, throw IOE
    // the first time.  'Succeed' the second time we are called.
    Mockito.when(implementation.getRegionInfo((byte[]) Mockito.any()))
        .thenThrow(new IOException("Server not running, aborting"))
        .thenReturn(new HRegionInfo());

    // After we encounter the above 'Server not running', we should catch the
    // IOE and go into retrying for the meta mode.  We'll do gets on -ROOT- to
    // get new meta location.  Return something so this 'get' succeeds
    // (here we mock up getRegionServerWithRetries, the wrapper around
    // the actual get).

    // TODO: Refactor.  This method has been moved out of HConnection.
    // It works for now but has been deprecated.
    Mockito.when(connection.getRegionServerWithRetries((ServerCallable<Result>) Mockito.any()))
        .thenReturn(getMetaTableRowResult());

    // Now start up the catalogtracker with our doctored Connection.
    final CatalogTracker ct = constructAndStartCatalogTracker(connection);
    try {
      // Set a location for root and meta.
      RootLocationEditor.setRootLocation(this.watcher, SN);
      ct.setMetaLocation(SN);
      // Call the method that HBASE-4288 calls.  It will try and verify the
      // meta location and will fail on first attempt then go into a long wait.
      // So, do this in a thread and then reset meta location to break it out
      // of its wait after a bit of time.
      final AtomicBoolean metaSet = new AtomicBoolean(false);
      final CountDownLatch latch = new CountDownLatch(1);
      Thread t =
          new Thread() {
            @Override
            public void run() {
              try {
                latch.countDown();
                metaSet.set(ct.waitForMeta(100000) != null);
              } catch (Exception e) {
                throw new RuntimeException(e);
              }
            }
          };
      t.start();
      latch.await();
      Threads.sleep(1);
      // Now reset the meta as though it were redeployed.
      ct.setMetaLocation(SN);
      t.join();
      Assert.assertTrue(metaSet.get());
    } finally {
      // Clean out root and meta locations or later tests will be confused...
      // they presume start fresh in zk.
      ct.resetMetaLocation();
    }
  }