/**
  * Test adding server to draining servers and then move regions off it. Make sure that no regions
  * are moved back to the draining server.
  *
  * @throws IOException
  * @throws KeeperException
  */
 @Test // (timeout=30000)
 public void testDrainingServerOffloading() throws Exception {
   // I need master in the below.
   HMaster master = TEST_UTIL.getMiniHBaseCluster().getMaster();
   HRegionInfo hriToMoveBack = null;
   // Set first server as draining server.
   HRegionServer drainingServer =
       setDrainingServer(TEST_UTIL.getMiniHBaseCluster().getRegionServer(0));
   try {
     final int regionsOnDrainingServer = drainingServer.getNumberOfOnlineRegions();
     Assert.assertTrue(regionsOnDrainingServer > 0);
     List<HRegionInfo> hris = ProtobufUtil.getOnlineRegions(drainingServer);
     for (HRegionInfo hri : hris) {
       // Pass null and AssignmentManager will chose a random server BUT it
       // should exclude draining servers.
       master.moveRegion(
           null, RequestConverter.buildMoveRegionRequest(hri.getEncodedNameAsBytes(), null));
       // Save off region to move back.
       hriToMoveBack = hri;
     }
     // Wait for regions to come back on line again.
     waitForAllRegionsOnline();
     Assert.assertEquals(0, drainingServer.getNumberOfOnlineRegions());
   } finally {
     unsetDrainingServer(drainingServer);
   }
   // Now we've unset the draining server, we should be able to move a region
   // to what was the draining server.
   master.moveRegion(
       null,
       RequestConverter.buildMoveRegionRequest(
           hriToMoveBack.getEncodedNameAsBytes(),
           Bytes.toBytes(drainingServer.getServerName().toString())));
   // Wait for regions to come back on line again.
   waitForAllRegionsOnline();
   Assert.assertEquals(1, drainingServer.getNumberOfOnlineRegions());
 }
  // check each region whether the coprocessor upcalls are called or not.
  private void verifyMethodResult(
      Class<?> c, String methodName[], TableName tableName, Object value[]) throws IOException {
    try {
      for (JVMClusterUtil.RegionServerThread t : cluster.getRegionServerThreads()) {
        if (!t.isAlive() || t.getRegionServer().isAborted() || t.getRegionServer().isStopping()) {
          continue;
        }
        for (HRegionInfo r : ProtobufUtil.getOnlineRegions(t.getRegionServer())) {
          if (!r.getTable().equals(tableName)) {
            continue;
          }
          RegionCoprocessorHost cph =
              t.getRegionServer().getOnlineRegion(r.getRegionName()).getCoprocessorHost();

          Coprocessor cp = cph.findCoprocessor(c.getName());
          assertNotNull(cp);
          for (int i = 0; i < methodName.length; ++i) {
            Method m = c.getMethod(methodName[i]);
            Object o = m.invoke(cp);
            assertTrue(
                "Result of "
                    + c.getName()
                    + "."
                    + methodName[i]
                    + " is expected to be "
                    + value[i].toString()
                    + ", while we get "
                    + o.toString(),
                o.equals(value[i]));
          }
        }
      }
    } catch (Exception e) {
      throw new IOException(e.toString());
    }
  }
  /** Spin up a cluster with a bunch of regions on it. */
  @BeforeClass
  public static void setUpBeforeClass() throws Exception {
    TEST_UTIL.startMiniCluster(NB_SLAVES);
    TEST_UTIL.getHBaseCluster().waitForActiveAndReadyMaster();
    TEST_UTIL.getConfiguration().setBoolean("hbase.master.enabletable.roundrobin", true);

    final List<String> families = new ArrayList<String>(1);
    families.add("family");
    TEST_UTIL.createRandomTable("table", families, 1, 0, 0, COUNT_OF_REGIONS, 0);

    // Ensure a stable env
    TEST_UTIL.getHBaseAdmin().setBalancerRunning(false, false);

    boolean ready = false;
    while (!ready) {
      waitForAllRegionsOnline();

      // Assert that every regionserver has some regions on it.
      int i = 0;
      ready = true;
      while (i < NB_SLAVES && ready) {
        HRegionServer hrs = TEST_UTIL.getMiniHBaseCluster().getRegionServer(i);
        if (ProtobufUtil.getOnlineRegions(hrs).isEmpty()) {
          ready = false;
        }
        i++;
      }

      if (!ready) {
        TEST_UTIL.getHBaseAdmin().setBalancerRunning(true, true);
        Assert.assertTrue("Can't start a balance!", TEST_UTIL.getHBaseAdmin().balancer());
        TEST_UTIL.getHBaseAdmin().setBalancerRunning(false, false);
        Thread.sleep(100);
      }
    }
  }
  /**
   * Test the global mem store size in the region server is equal to sum of each region's mem store
   * size
   *
   * @throws Exception
   */
  @Test
  public void testGlobalMemStore() throws Exception {
    // Start the cluster
    LOG.info("Starting cluster");
    Configuration conf = HBaseConfiguration.create();
    TEST_UTIL = new HBaseTestingUtility(conf);
    TEST_UTIL.startMiniCluster(1, regionServerNum);
    cluster = TEST_UTIL.getHBaseCluster();
    LOG.info("Waiting for active/ready master");
    cluster.waitForActiveAndReadyMaster();

    // Create a table with regions
    TableName table = TableName.valueOf("TestGlobalMemStoreSize");
    byte[] family = Bytes.toBytes("family");
    LOG.info("Creating table with " + regionNum + " regions");
    Table ht = TEST_UTIL.createMultiRegionTable(table, family, regionNum);
    int numRegions = -1;
    try (RegionLocator r = TEST_UTIL.getConnection().getRegionLocator(table)) {
      numRegions = r.getStartKeys().length;
    }
    assertEquals(regionNum, numRegions);
    waitForAllRegionsAssigned();

    for (HRegionServer server : getOnlineRegionServers()) {
      long globalMemStoreSize = 0;
      for (HRegionInfo regionInfo : ProtobufUtil.getOnlineRegions(server.getRSRpcServices())) {
        globalMemStoreSize +=
            server.getFromOnlineRegions(regionInfo.getEncodedName()).getMemstoreSize();
      }
      assertEquals(server.getRegionServerAccounting().getGlobalMemstoreSize(), globalMemStoreSize);
    }

    // check the global memstore size after flush
    int i = 0;
    for (HRegionServer server : getOnlineRegionServers()) {
      LOG.info(
          "Starting flushes on "
              + server.getServerName()
              + ", size="
              + server.getRegionServerAccounting().getGlobalMemstoreSize());

      for (HRegionInfo regionInfo : ProtobufUtil.getOnlineRegions(server.getRSRpcServices())) {
        Region r = server.getFromOnlineRegions(regionInfo.getEncodedName());
        flush(r, server);
      }
      LOG.info("Post flush on " + server.getServerName());
      long now = System.currentTimeMillis();
      long timeout = now + 1000;
      while (server.getRegionServerAccounting().getGlobalMemstoreSize() != 0
          && timeout < System.currentTimeMillis()) {
        Threads.sleep(10);
      }
      long size = server.getRegionServerAccounting().getGlobalMemstoreSize();
      if (size > 0) {
        // If size > 0, see if its because the meta region got edits while
        // our test was running....
        for (HRegionInfo regionInfo : ProtobufUtil.getOnlineRegions(server.getRSRpcServices())) {
          Region r = server.getFromOnlineRegions(regionInfo.getEncodedName());
          long l = r.getMemstoreSize();
          if (l > 0) {
            // Only meta could have edits at this stage.  Give it another flush
            // clear them.
            assertTrue(regionInfo.isMetaRegion());
            LOG.info(r.toString() + " " + l + ", reflushing");
            r.flush(true);
          }
        }
      }
      size = server.getRegionServerAccounting().getGlobalMemstoreSize();
      assertEquals("Server=" + server.getServerName() + ", i=" + i++, 0, size);
    }

    ht.close();
    TEST_UTIL.shutdownMiniCluster();
  }