/**
  * Return how many regions will move per table since their primary RS will change
  *
  * @param newPlan - new AssignmentPlan
  * @return how many primaries will move per table
  */
 public Map<TableName, Integer> getRegionsMovement(FavoredNodesPlan newPlan) throws IOException {
   Map<TableName, Integer> movesPerTable = new HashMap<TableName, Integer>();
   SnapshotOfRegionAssignmentFromMeta snapshot = this.getRegionAssignmentSnapshot();
   Map<TableName, List<HRegionInfo>> tableToRegions = snapshot.getTableToRegionMap();
   FavoredNodesPlan oldPlan = snapshot.getExistingAssignmentPlan();
   Set<TableName> tables = snapshot.getTableSet();
   for (TableName table : tables) {
     int movedPrimaries = 0;
     if (!this.targetTableSet.isEmpty() && !this.targetTableSet.contains(table)) {
       continue;
     }
     List<HRegionInfo> regions = tableToRegions.get(table);
     for (HRegionInfo region : regions) {
       List<ServerName> oldServers = oldPlan.getFavoredNodes(region);
       List<ServerName> newServers = newPlan.getFavoredNodes(region);
       if (oldServers != null && newServers != null) {
         ServerName oldPrimary = oldServers.get(0);
         ServerName newPrimary = newServers.get(0);
         if (oldPrimary.compareTo(newPrimary) != 0) {
           movedPrimaries++;
         }
       }
     }
     movesPerTable.put(table, movedPrimaries);
   }
   return movesPerTable;
 }
 public void printLocalityAndDispersionForCurrentPlan(
     Map<String, Map<String, Float>> regionLocalityMap) throws IOException {
   SnapshotOfRegionAssignmentFromMeta snapshot = this.getRegionAssignmentSnapshot();
   FavoredNodesPlan assignmentPlan = snapshot.getExistingAssignmentPlan();
   Set<TableName> tables = snapshot.getTableSet();
   Map<TableName, List<HRegionInfo>> tableToRegionsMap = snapshot.getTableToRegionMap();
   for (TableName table : tables) {
     float[] locality = new float[3];
     if (!this.targetTableSet.isEmpty() && !this.targetTableSet.contains(table)) {
       continue;
     }
     List<HRegionInfo> regions = tableToRegionsMap.get(table);
     for (HRegionInfo currentRegion : regions) {
       Map<String, Float> regionLocality = regionLocalityMap.get(currentRegion.getEncodedName());
       if (regionLocality == null) {
         continue;
       }
       List<ServerName> servers = assignmentPlan.getFavoredNodes(currentRegion);
       if (servers != null) {
         int i = 0;
         for (FavoredNodesPlan.Position p : FavoredNodesPlan.Position.values()) {
           ServerName server = servers.get(p.ordinal());
           Float currentLocality = 0f;
           if (servers != null) {
             currentLocality = regionLocality.get(server.getHostname());
             if (currentLocality == null) {
               currentLocality = 0f;
             }
             locality[i] += currentLocality;
           }
           i++;
         }
       }
     }
     for (int i = 0; i < locality.length; i++) {
       String copy = null;
       if (i == 0) {
         copy = "primary";
       } else if (i == 1) {
         copy = "secondary";
       } else if (i == 2) {
         copy = "tertiary";
       }
       float avgLocality = 100 * locality[i] / regions.size();
       LOG.info(
           "For Table: "
               + table
               + " ; #Total Regions: "
               + regions.size()
               + " ; The average locality for "
               + copy
               + " is "
               + avgLocality
               + " %");
     }
     printDispersionScores(table, snapshot, regions.size(), null, false);
   }
 }
 /**
  * Update the assignment plan into hbase:meta
  *
  * @param plan the assignments plan to be updated into hbase:meta
  * @throws IOException if cannot update assignment plan in hbase:meta
  */
 public void updateAssignmentPlanToMeta(FavoredNodesPlan plan) throws IOException {
   try {
     LOG.info("Start to update the hbase:meta with the new assignment plan");
     Map<HRegionInfo, List<ServerName>> assignmentMap = plan.getAssignmentMap();
     FavoredNodeAssignmentHelper.updateMetaWithFavoredNodesInfo(assignmentMap, conf);
     LOG.info("Updated the hbase:meta with the new assignment plan");
   } catch (Exception e) {
     LOG.error(
         "Failed to update hbase:meta with the new assignment" + "plan because " + e.getMessage());
   }
 }
  /**
   * Print the assignment plan to the system output stream
   *
   * @param plan
   */
  public static void printAssignmentPlan(FavoredNodesPlan plan) {
    if (plan == null) return;
    LOG.info("========== Start to print the assignment plan ================");
    // sort the map based on region info
    Map<HRegionInfo, List<ServerName>> assignmentMap =
        new TreeMap<HRegionInfo, List<ServerName>>(plan.getAssignmentMap());

    for (Map.Entry<HRegionInfo, List<ServerName>> entry : assignmentMap.entrySet()) {

      String serverList = FavoredNodeAssignmentHelper.getFavoredNodesAsString(entry.getValue());
      String regionName = entry.getKey().getRegionNameAsString();
      LOG.info("Region: " + regionName);
      LOG.info("Its favored nodes: " + serverList);
    }
    LOG.info("========== Finish to print the assignment plan ================");
  }
  public static void main(String args[]) throws IOException {
    Options opt = new Options();
    opt.addOption("w", "write", false, "write the assignments to hbase:meta only");
    opt.addOption(
        "u", "update", false, "update the assignments to hbase:meta and RegionServers together");
    opt.addOption("n", "dry-run", false, "do not write assignments to META");
    opt.addOption("v", "verify", false, "verify current assignments against META");
    opt.addOption("p", "print", false, "print the current assignment plan in META");
    opt.addOption("h", "help", false, "print usage");
    opt.addOption("d", "verification-details", false, "print the details of verification report");

    opt.addOption("zk", true, "to set the zookeeper quorum");
    opt.addOption("fs", true, "to set HDFS");
    opt.addOption("hbase_root", true, "to set hbase_root directory");

    opt.addOption(
        "overwrite",
        false,
        "overwrite the favored nodes for a single region,"
            + "for example: -update -r regionName -f server1:port,server2:port,server3:port");
    opt.addOption("r", true, "The region name that needs to be updated");
    opt.addOption("f", true, "The new favored nodes");

    opt.addOption(
        "tables",
        true,
        "The list of table names splitted by ',' ;" + "For example: -tables: t1,t2,...,tn");
    opt.addOption("l", "locality", true, "enforce the maxium locality");
    opt.addOption("m", "min-move", true, "enforce minium assignment move");
    opt.addOption("diff", false, "calculate difference between assignment plans");
    opt.addOption("munkres", false, "use munkres to place secondaries and tertiaries");
    opt.addOption(
        "ld",
        "locality-dispersion",
        false,
        "print locality and dispersion " + "information for current plan");
    try {
      // Set the log4j
      Logger.getLogger("org.apache.zookeeper").setLevel(Level.ERROR);
      Logger.getLogger("org.apache.hadoop.hbase").setLevel(Level.ERROR);
      Logger.getLogger("org.apache.hadoop.hbase.master.RegionPlacementMaintainer")
          .setLevel(Level.INFO);

      CommandLine cmd = new GnuParser().parse(opt, args);
      Configuration conf = HBaseConfiguration.create();

      boolean enforceMinAssignmentMove = true;
      boolean enforceLocality = true;
      boolean verificationDetails = false;

      // Read all the options
      if ((cmd.hasOption("l") && cmd.getOptionValue("l").equalsIgnoreCase("false"))
          || (cmd.hasOption("locality")
              && cmd.getOptionValue("locality").equalsIgnoreCase("false"))) {
        enforceLocality = false;
      }

      if ((cmd.hasOption("m") && cmd.getOptionValue("m").equalsIgnoreCase("false"))
          || (cmd.hasOption("min-move")
              && cmd.getOptionValue("min-move").equalsIgnoreCase("false"))) {
        enforceMinAssignmentMove = false;
      }

      if (cmd.hasOption("zk")) {
        conf.set(HConstants.ZOOKEEPER_QUORUM, cmd.getOptionValue("zk"));
        LOG.info("Setting the zk quorum: " + conf.get(HConstants.ZOOKEEPER_QUORUM));
      }

      if (cmd.hasOption("fs")) {
        conf.set(FileSystem.FS_DEFAULT_NAME_KEY, cmd.getOptionValue("fs"));
        LOG.info("Setting the HDFS: " + conf.get(FileSystem.FS_DEFAULT_NAME_KEY));
      }

      if (cmd.hasOption("hbase_root")) {
        conf.set(HConstants.HBASE_DIR, cmd.getOptionValue("hbase_root"));
        LOG.info("Setting the hbase root directory: " + conf.get(HConstants.HBASE_DIR));
      }

      // Create the region placement obj
      RegionPlacementMaintainer rp =
          new RegionPlacementMaintainer(conf, enforceLocality, enforceMinAssignmentMove);

      if (cmd.hasOption("d") || cmd.hasOption("verification-details")) {
        verificationDetails = true;
      }

      if (cmd.hasOption("tables")) {
        String tableNameListStr = cmd.getOptionValue("tables");
        String[] tableNames = StringUtils.split(tableNameListStr, ",");
        rp.setTargetTableName(tableNames);
      }

      if (cmd.hasOption("munkres")) {
        USE_MUNKRES_FOR_PLACING_SECONDARY_AND_TERTIARY = true;
      }

      // Read all the modes
      if (cmd.hasOption("v") || cmd.hasOption("verify")) {
        // Verify the region placement.
        rp.verifyRegionPlacement(verificationDetails);
      } else if (cmd.hasOption("n") || cmd.hasOption("dry-run")) {
        // Generate the assignment plan only without updating the hbase:meta and RS
        FavoredNodesPlan plan = rp.getNewAssignmentPlan();
        printAssignmentPlan(plan);
      } else if (cmd.hasOption("w") || cmd.hasOption("write")) {
        // Generate the new assignment plan
        FavoredNodesPlan plan = rp.getNewAssignmentPlan();
        // Print the new assignment plan
        printAssignmentPlan(plan);
        // Write the new assignment plan to META
        rp.updateAssignmentPlanToMeta(plan);
      } else if (cmd.hasOption("u") || cmd.hasOption("update")) {
        // Generate the new assignment plan
        FavoredNodesPlan plan = rp.getNewAssignmentPlan();
        // Print the new assignment plan
        printAssignmentPlan(plan);
        // Update the assignment to hbase:meta and Region Servers
        rp.updateAssignmentPlan(plan);
      } else if (cmd.hasOption("diff")) {
        FavoredNodesPlan newPlan = rp.getNewAssignmentPlan();
        Map<String, Map<String, Float>> locality =
            FSUtils.getRegionDegreeLocalityMappingFromFS(conf);
        Map<TableName, Integer> movesPerTable = rp.getRegionsMovement(newPlan);
        rp.checkDifferencesWithOldPlan(movesPerTable, locality, newPlan);
        System.out.println("Do you want to update the assignment plan? [y/n]");
        Scanner s = new Scanner(System.in);
        String input = s.nextLine().trim();
        if (input.equals("y")) {
          System.out.println("Updating assignment plan...");
          rp.updateAssignmentPlan(newPlan);
        }
        s.close();
      } else if (cmd.hasOption("ld")) {
        Map<String, Map<String, Float>> locality =
            FSUtils.getRegionDegreeLocalityMappingFromFS(conf);
        rp.printLocalityAndDispersionForCurrentPlan(locality);
      } else if (cmd.hasOption("p") || cmd.hasOption("print")) {
        FavoredNodesPlan plan = rp.getRegionAssignmentSnapshot().getExistingAssignmentPlan();
        printAssignmentPlan(plan);
      } else if (cmd.hasOption("overwrite")) {
        if (!cmd.hasOption("f") || !cmd.hasOption("r")) {
          throw new IllegalArgumentException(
              "Please specify: "
                  + " -update -r regionName -f server1:port,server2:port,server3:port");
        }

        String regionName = cmd.getOptionValue("r");
        String favoredNodesStr = cmd.getOptionValue("f");
        LOG.info(
            "Going to update the region "
                + regionName
                + " with the new favored nodes "
                + favoredNodesStr);
        List<ServerName> favoredNodes = null;
        HRegionInfo regionInfo =
            rp.getRegionAssignmentSnapshot().getRegionNameToRegionInfoMap().get(regionName);
        if (regionInfo == null) {
          LOG.error("Cannot find the region " + regionName + " from the META");
        } else {
          try {
            favoredNodes = getFavoredNodeList(favoredNodesStr);
          } catch (IllegalArgumentException e) {
            LOG.error("Cannot parse the invalid favored nodes because " + e);
          }
          FavoredNodesPlan newPlan = new FavoredNodesPlan();
          newPlan.updateAssignmentPlan(regionInfo, favoredNodes);
          rp.updateAssignmentPlan(newPlan);
        }
      } else {
        printHelp(opt);
      }
    } catch (ParseException e) {
      printHelp(opt);
    }
  }
 /**
  * Compares two plans and check whether the locality dropped or increased (prints the information
  * as a string) also prints the baseline locality
  *
  * @param movesPerTable - how many primary regions will move per table
  * @param regionLocalityMap - locality map from FS
  * @param newPlan - new assignment plan
  * @throws IOException
  */
 public void checkDifferencesWithOldPlan(
     Map<TableName, Integer> movesPerTable,
     Map<String, Map<String, Float>> regionLocalityMap,
     FavoredNodesPlan newPlan)
     throws IOException {
   // localities for primary, secondary and tertiary
   SnapshotOfRegionAssignmentFromMeta snapshot = this.getRegionAssignmentSnapshot();
   FavoredNodesPlan oldPlan = snapshot.getExistingAssignmentPlan();
   Set<TableName> tables = snapshot.getTableSet();
   Map<TableName, List<HRegionInfo>> tableToRegionsMap = snapshot.getTableToRegionMap();
   for (TableName table : tables) {
     float[] deltaLocality = new float[3];
     float[] locality = new float[3];
     if (!this.targetTableSet.isEmpty() && !this.targetTableSet.contains(table)) {
       continue;
     }
     List<HRegionInfo> regions = tableToRegionsMap.get(table);
     System.out.println("==================================================");
     System.out.println("Assignment Plan Projection Report For Table: " + table);
     System.out.println("\t Total regions: " + regions.size());
     System.out.println(
         "\t"
             + movesPerTable.get(table)
             + " primaries will move due to their primary has changed");
     for (HRegionInfo currentRegion : regions) {
       Map<String, Float> regionLocality = regionLocalityMap.get(currentRegion.getEncodedName());
       if (regionLocality == null) {
         continue;
       }
       List<ServerName> oldServers = oldPlan.getFavoredNodes(currentRegion);
       List<ServerName> newServers = newPlan.getFavoredNodes(currentRegion);
       if (newServers != null && oldServers != null) {
         int i = 0;
         for (FavoredNodesPlan.Position p : FavoredNodesPlan.Position.values()) {
           ServerName newServer = newServers.get(p.ordinal());
           ServerName oldServer = oldServers.get(p.ordinal());
           Float oldLocality = 0f;
           if (oldServers != null) {
             oldLocality = regionLocality.get(oldServer.getHostname());
             if (oldLocality == null) {
               oldLocality = 0f;
             }
             locality[i] += oldLocality;
           }
           Float newLocality = regionLocality.get(newServer.getHostname());
           if (newLocality == null) {
             newLocality = 0f;
           }
           deltaLocality[i] += newLocality - oldLocality;
           i++;
         }
       }
     }
     DecimalFormat df = new java.text.DecimalFormat("#.##");
     for (int i = 0; i < deltaLocality.length; i++) {
       System.out.print("\t\t Baseline locality for ");
       if (i == 0) {
         System.out.print("primary ");
       } else if (i == 1) {
         System.out.print("secondary ");
       } else if (i == 2) {
         System.out.print("tertiary ");
       }
       System.out.println(df.format(100 * locality[i] / regions.size()) + "%");
       System.out.print("\t\t Locality will change with the new plan: ");
       System.out.println(df.format(100 * deltaLocality[i] / regions.size()) + "%");
     }
     System.out.println("\t Baseline dispersion");
     printDispersionScores(table, snapshot, regions.size(), null, true);
     System.out.println("\t Projected dispersion");
     printDispersionScores(table, snapshot, regions.size(), newPlan, true);
   }
 }
  /**
   * Update the assignment plan to all the region servers
   *
   * @param plan
   * @throws IOException
   */
  private void updateAssignmentPlanToRegionServers(FavoredNodesPlan plan) throws IOException {
    LOG.info("Start to update the region servers with the new assignment plan");
    // Get the region to region server map
    Map<ServerName, List<HRegionInfo>> currentAssignment =
        this.getRegionAssignmentSnapshot().getRegionServerToRegionMap();

    // track of the failed and succeeded updates
    int succeededNum = 0;
    Map<ServerName, Exception> failedUpdateMap = new HashMap<ServerName, Exception>();

    for (Map.Entry<ServerName, List<HRegionInfo>> entry : currentAssignment.entrySet()) {
      List<Pair<HRegionInfo, List<ServerName>>> regionUpdateInfos =
          new ArrayList<Pair<HRegionInfo, List<ServerName>>>();
      try {
        // Keep track of the favored updates for the current region server
        FavoredNodesPlan singleServerPlan = null;
        // Find out all the updates for the current region server
        for (HRegionInfo region : entry.getValue()) {
          List<ServerName> favoredServerList = plan.getFavoredNodes(region);
          if (favoredServerList != null
              && favoredServerList.size() == FavoredNodeAssignmentHelper.FAVORED_NODES_NUM) {
            // Create the single server plan if necessary
            if (singleServerPlan == null) {
              singleServerPlan = new FavoredNodesPlan();
            }
            // Update the single server update
            singleServerPlan.updateAssignmentPlan(region, favoredServerList);
            regionUpdateInfos.add(
                new Pair<HRegionInfo, List<ServerName>>(region, favoredServerList));
          }
        }
        if (singleServerPlan != null) {
          // Update the current region server with its updated favored nodes
          BlockingInterface currentRegionServer =
              ((ClusterConnection) this.connection).getAdmin(entry.getKey());
          UpdateFavoredNodesRequest request =
              RequestConverter.buildUpdateFavoredNodesRequest(regionUpdateInfos);

          UpdateFavoredNodesResponse updateFavoredNodesResponse =
              currentRegionServer.updateFavoredNodes(null, request);
          LOG.info(
              "Region server "
                  + ProtobufUtil.getServerInfo(null, currentRegionServer).getServerName()
                  + " has updated "
                  + updateFavoredNodesResponse.getResponse()
                  + " / "
                  + singleServerPlan.getAssignmentMap().size()
                  + " regions with the assignment plan");
          succeededNum++;
        }
      } catch (Exception e) {
        failedUpdateMap.put(entry.getKey(), e);
      }
    }
    // log the succeeded updates
    LOG.info("Updated " + succeededNum + " region servers with " + "the new assignment plan");

    // log the failed updates
    int failedNum = failedUpdateMap.size();
    if (failedNum != 0) {
      LOG.error(
          "Failed to update the following + "
              + failedNum
              + " region servers with its corresponding favored nodes");
      for (Map.Entry<ServerName, Exception> entry : failedUpdateMap.entrySet()) {
        LOG.error(
            "Failed to update "
                + entry.getKey().getHostAndPort()
                + " because of "
                + entry.getValue().getMessage());
      }
    }
  }
  /**
   * Generate the assignment plan for the existing table
   *
   * @param tableName
   * @param assignmentSnapshot
   * @param regionLocalityMap
   * @param plan
   * @param munkresForSecondaryAndTertiary if set on true the assignment plan for the tertiary and
   *     secondary will be generated with Munkres algorithm, otherwise will be generated using
   *     placeSecondaryAndTertiaryRS
   * @throws IOException
   */
  private void genAssignmentPlan(
      TableName tableName,
      SnapshotOfRegionAssignmentFromMeta assignmentSnapshot,
      Map<String, Map<String, Float>> regionLocalityMap,
      FavoredNodesPlan plan,
      boolean munkresForSecondaryAndTertiary)
      throws IOException {
    // Get the all the regions for the current table
    List<HRegionInfo> regions = assignmentSnapshot.getTableToRegionMap().get(tableName);
    int numRegions = regions.size();

    // Get the current assignment map
    Map<HRegionInfo, ServerName> currentAssignmentMap =
        assignmentSnapshot.getRegionToRegionServerMap();

    // Get the all the region servers
    List<ServerName> servers = new ArrayList<ServerName>();
    try (Admin admin = this.connection.getAdmin()) {
      servers.addAll(admin.getClusterStatus().getServers());
    }

    LOG.info(
        "Start to generate assignment plan for "
            + numRegions
            + " regions from table "
            + tableName
            + " with "
            + servers.size()
            + " region servers");

    int slotsPerServer = (int) Math.ceil((float) numRegions / servers.size());
    int regionSlots = slotsPerServer * servers.size();

    // Compute the primary, secondary and tertiary costs for each region/server
    // pair. These costs are based only on node locality and rack locality, and
    // will be modified later.
    float[][] primaryCost = new float[numRegions][regionSlots];
    float[][] secondaryCost = new float[numRegions][regionSlots];
    float[][] tertiaryCost = new float[numRegions][regionSlots];

    if (this.enforceLocality && regionLocalityMap != null) {
      // Transform the locality mapping into a 2D array, assuming that any
      // unspecified locality value is 0.
      float[][] localityPerServer = new float[numRegions][regionSlots];
      for (int i = 0; i < numRegions; i++) {
        Map<String, Float> serverLocalityMap =
            regionLocalityMap.get(regions.get(i).getEncodedName());
        if (serverLocalityMap == null) {
          continue;
        }
        for (int j = 0; j < servers.size(); j++) {
          String serverName = servers.get(j).getHostname();
          if (serverName == null) {
            continue;
          }
          Float locality = serverLocalityMap.get(serverName);
          if (locality == null) {
            continue;
          }
          for (int k = 0; k < slotsPerServer; k++) {
            // If we can't find the locality of a region to a server, which occurs
            // because locality is only reported for servers which have some
            // blocks of a region local, then the locality for that pair is 0.
            localityPerServer[i][j * slotsPerServer + k] = locality.floatValue();
          }
        }
      }

      // Compute the total rack locality for each region in each rack. The total
      // rack locality is the sum of the localities of a region on all servers in
      // a rack.
      Map<String, Map<HRegionInfo, Float>> rackRegionLocality =
          new HashMap<String, Map<HRegionInfo, Float>>();
      for (int i = 0; i < numRegions; i++) {
        HRegionInfo region = regions.get(i);
        for (int j = 0; j < regionSlots; j += slotsPerServer) {
          String rack = rackManager.getRack(servers.get(j / slotsPerServer));
          Map<HRegionInfo, Float> rackLocality = rackRegionLocality.get(rack);
          if (rackLocality == null) {
            rackLocality = new HashMap<HRegionInfo, Float>();
            rackRegionLocality.put(rack, rackLocality);
          }
          Float localityObj = rackLocality.get(region);
          float locality = localityObj == null ? 0 : localityObj.floatValue();
          locality += localityPerServer[i][j];
          rackLocality.put(region, locality);
        }
      }
      for (int i = 0; i < numRegions; i++) {
        for (int j = 0; j < regionSlots; j++) {
          String rack = rackManager.getRack(servers.get(j / slotsPerServer));
          Float totalRackLocalityObj = rackRegionLocality.get(rack).get(regions.get(i));
          float totalRackLocality =
              totalRackLocalityObj == null ? 0 : totalRackLocalityObj.floatValue();

          // Primary cost aims to favor servers with high node locality and low
          // rack locality, so that secondaries and tertiaries can be chosen for
          // nodes with high rack locality. This might give primaries with
          // slightly less locality at first compared to a cost which only
          // considers the node locality, but should be better in the long run.
          primaryCost[i][j] = 1 - (2 * localityPerServer[i][j] - totalRackLocality);

          // Secondary cost aims to favor servers with high node locality and high
          // rack locality since the tertiary will be chosen from the same rack as
          // the secondary. This could be negative, but that is okay.
          secondaryCost[i][j] = 2 - (localityPerServer[i][j] + totalRackLocality);

          // Tertiary cost is only concerned with the node locality. It will later
          // be restricted to only hosts on the same rack as the secondary.
          tertiaryCost[i][j] = 1 - localityPerServer[i][j];
        }
      }
    }

    if (this.enforceMinAssignmentMove && currentAssignmentMap != null) {
      // We want to minimize the number of regions which move as the result of a
      // new assignment. Therefore, slightly penalize any placement which is for
      // a host that is not currently serving the region.
      for (int i = 0; i < numRegions; i++) {
        for (int j = 0; j < servers.size(); j++) {
          ServerName currentAddress = currentAssignmentMap.get(regions.get(i));
          if (currentAddress != null && !currentAddress.equals(servers.get(j))) {
            for (int k = 0; k < slotsPerServer; k++) {
              primaryCost[i][j * slotsPerServer + k] += NOT_CURRENT_HOST_PENALTY;
            }
          }
        }
      }
    }

    // Artificially increase cost of last slot of each server to evenly
    // distribute the slop, otherwise there will be a few servers with too few
    // regions and many servers with the max number of regions.
    for (int i = 0; i < numRegions; i++) {
      for (int j = 0; j < regionSlots; j += slotsPerServer) {
        primaryCost[i][j] += LAST_SLOT_COST_PENALTY;
        secondaryCost[i][j] += LAST_SLOT_COST_PENALTY;
        tertiaryCost[i][j] += LAST_SLOT_COST_PENALTY;
      }
    }

    RandomizedMatrix randomizedMatrix = new RandomizedMatrix(numRegions, regionSlots);
    primaryCost = randomizedMatrix.transform(primaryCost);
    int[] primaryAssignment = new MunkresAssignment(primaryCost).solve();
    primaryAssignment = randomizedMatrix.invertIndices(primaryAssignment);

    // Modify the secondary and tertiary costs for each region/server pair to
    // prevent a region from being assigned to the same rack for both primary
    // and either one of secondary or tertiary.
    for (int i = 0; i < numRegions; i++) {
      int slot = primaryAssignment[i];
      String rack = rackManager.getRack(servers.get(slot / slotsPerServer));
      for (int k = 0; k < servers.size(); k++) {
        if (!rackManager.getRack(servers.get(k)).equals(rack)) {
          continue;
        }
        if (k == slot / slotsPerServer) {
          // Same node, do not place secondary or tertiary here ever.
          for (int m = 0; m < slotsPerServer; m++) {
            secondaryCost[i][k * slotsPerServer + m] = MAX_COST;
            tertiaryCost[i][k * slotsPerServer + m] = MAX_COST;
          }
        } else {
          // Same rack, do not place secondary or tertiary here if possible.
          for (int m = 0; m < slotsPerServer; m++) {
            secondaryCost[i][k * slotsPerServer + m] = AVOID_COST;
            tertiaryCost[i][k * slotsPerServer + m] = AVOID_COST;
          }
        }
      }
    }
    if (munkresForSecondaryAndTertiary) {
      randomizedMatrix = new RandomizedMatrix(numRegions, regionSlots);
      secondaryCost = randomizedMatrix.transform(secondaryCost);
      int[] secondaryAssignment = new MunkresAssignment(secondaryCost).solve();
      secondaryAssignment = randomizedMatrix.invertIndices(secondaryAssignment);

      // Modify the tertiary costs for each region/server pair to ensure that a
      // region is assigned to a tertiary server on the same rack as its secondary
      // server, but not the same server in that rack.
      for (int i = 0; i < numRegions; i++) {
        int slot = secondaryAssignment[i];
        String rack = rackManager.getRack(servers.get(slot / slotsPerServer));
        for (int k = 0; k < servers.size(); k++) {
          if (k == slot / slotsPerServer) {
            // Same node, do not place tertiary here ever.
            for (int m = 0; m < slotsPerServer; m++) {
              tertiaryCost[i][k * slotsPerServer + m] = MAX_COST;
            }
          } else {
            if (rackManager.getRack(servers.get(k)).equals(rack)) {
              continue;
            }
            // Different rack, do not place tertiary here if possible.
            for (int m = 0; m < slotsPerServer; m++) {
              tertiaryCost[i][k * slotsPerServer + m] = AVOID_COST;
            }
          }
        }
      }

      randomizedMatrix = new RandomizedMatrix(numRegions, regionSlots);
      tertiaryCost = randomizedMatrix.transform(tertiaryCost);
      int[] tertiaryAssignment = new MunkresAssignment(tertiaryCost).solve();
      tertiaryAssignment = randomizedMatrix.invertIndices(tertiaryAssignment);

      for (int i = 0; i < numRegions; i++) {
        List<ServerName> favoredServers =
            new ArrayList<ServerName>(FavoredNodeAssignmentHelper.FAVORED_NODES_NUM);
        ServerName s = servers.get(primaryAssignment[i] / slotsPerServer);
        favoredServers.add(
            ServerName.valueOf(s.getHostname(), s.getPort(), ServerName.NON_STARTCODE));

        s = servers.get(secondaryAssignment[i] / slotsPerServer);
        favoredServers.add(
            ServerName.valueOf(s.getHostname(), s.getPort(), ServerName.NON_STARTCODE));

        s = servers.get(tertiaryAssignment[i] / slotsPerServer);
        favoredServers.add(
            ServerName.valueOf(s.getHostname(), s.getPort(), ServerName.NON_STARTCODE));
        // Update the assignment plan
        plan.updateAssignmentPlan(regions.get(i), favoredServers);
      }
      LOG.info(
          "Generated the assignment plan for "
              + numRegions
              + " regions from table "
              + tableName
              + " with "
              + servers.size()
              + " region servers");
      LOG.info("Assignment plan for secondary and tertiary generated " + "using MunkresAssignment");
    } else {
      Map<HRegionInfo, ServerName> primaryRSMap = new HashMap<HRegionInfo, ServerName>();
      for (int i = 0; i < numRegions; i++) {
        primaryRSMap.put(regions.get(i), servers.get(primaryAssignment[i] / slotsPerServer));
      }
      FavoredNodeAssignmentHelper favoredNodeHelper =
          new FavoredNodeAssignmentHelper(servers, conf);
      favoredNodeHelper.initialize();
      Map<HRegionInfo, ServerName[]> secondaryAndTertiaryMap =
          favoredNodeHelper.placeSecondaryAndTertiaryWithRestrictions(primaryRSMap);
      for (int i = 0; i < numRegions; i++) {
        List<ServerName> favoredServers =
            new ArrayList<ServerName>(FavoredNodeAssignmentHelper.FAVORED_NODES_NUM);
        HRegionInfo currentRegion = regions.get(i);
        ServerName s = primaryRSMap.get(currentRegion);
        favoredServers.add(
            ServerName.valueOf(s.getHostname(), s.getPort(), ServerName.NON_STARTCODE));

        ServerName[] secondaryAndTertiary = secondaryAndTertiaryMap.get(currentRegion);
        s = secondaryAndTertiary[0];
        favoredServers.add(
            ServerName.valueOf(s.getHostname(), s.getPort(), ServerName.NON_STARTCODE));

        s = secondaryAndTertiary[1];
        favoredServers.add(
            ServerName.valueOf(s.getHostname(), s.getPort(), ServerName.NON_STARTCODE));
        // Update the assignment plan
        plan.updateAssignmentPlan(regions.get(i), favoredServers);
      }
      LOG.info(
          "Generated the assignment plan for "
              + numRegions
              + " regions from table "
              + tableName
              + " with "
              + servers.size()
              + " region servers");
      LOG.info(
          "Assignment plan for secondary and tertiary generated "
              + "using placeSecondaryAndTertiaryWithRestrictions method");
    }
  }
  public void fillUp(
      TableName tableName,
      SnapshotOfRegionAssignmentFromMeta snapshot,
      Map<String, Map<String, Float>> regionLocalityMap) {
    // Set the table name
    this.tableName = tableName;

    // Get all the regions for this table
    List<HRegionInfo> regionInfoList = snapshot.getTableToRegionMap().get(tableName);
    // Get the total region num for the current table
    this.totalRegions = regionInfoList.size();

    // Get the existing assignment plan
    FavoredNodesPlan favoredNodesAssignment = snapshot.getExistingAssignmentPlan();
    // Get the region to region server mapping
    Map<HRegionInfo, ServerName> currentAssignment = snapshot.getRegionToRegionServerMap();
    // Initialize the server to its hosing region counter map
    Map<ServerName, Integer> serverToHostingRegionCounterMap = new HashMap<ServerName, Integer>();

    Map<ServerName, Integer> primaryRSToRegionCounterMap = new HashMap<ServerName, Integer>();
    Map<ServerName, Set<ServerName>> primaryToSecTerRSMap =
        new HashMap<ServerName, Set<ServerName>>();

    // Check the favored nodes and its locality information
    // Also keep tracker of the most loaded and least loaded region servers
    for (HRegionInfo region : regionInfoList) {
      try {
        ServerName currentRS = currentAssignment.get(region);
        // Handle unassigned regions
        if (currentRS == null) {
          unAssignedRegionsList.add(region);
          continue;
        }

        // Keep updating the server to is hosting region counter map
        Integer hostRegionCounter = serverToHostingRegionCounterMap.get(currentRS);
        if (hostRegionCounter == null) {
          hostRegionCounter = Integer.valueOf(0);
        }
        hostRegionCounter = hostRegionCounter.intValue() + 1;
        serverToHostingRegionCounterMap.put(currentRS, hostRegionCounter);

        // Get the favored nodes from the assignment plan and verify it.
        List<ServerName> favoredNodes = favoredNodesAssignment.getFavoredNodes(region);
        if (favoredNodes == null
            || favoredNodes.size() != FavoredNodeAssignmentHelper.FAVORED_NODES_NUM) {
          regionsWithoutValidFavoredNodes.add(region);
          continue;
        }
        // Get the primary, secondary and tertiary region server
        ServerName primaryRS = favoredNodes.get(FavoredNodesPlan.Position.PRIMARY.ordinal());
        ServerName secondaryRS = favoredNodes.get(FavoredNodesPlan.Position.SECONDARY.ordinal());
        ServerName tertiaryRS = favoredNodes.get(FavoredNodesPlan.Position.TERTIARY.ordinal());

        // Update the primary rs to its region set map
        Integer regionCounter = primaryRSToRegionCounterMap.get(primaryRS);
        if (regionCounter == null) {
          regionCounter = Integer.valueOf(0);
        }
        regionCounter = regionCounter.intValue() + 1;
        primaryRSToRegionCounterMap.put(primaryRS, regionCounter);

        // Update the primary rs to secondary and tertiary rs map
        Set<ServerName> secAndTerSet = primaryToSecTerRSMap.get(primaryRS);
        if (secAndTerSet == null) {
          secAndTerSet = new HashSet<ServerName>();
        }
        secAndTerSet.add(secondaryRS);
        secAndTerSet.add(tertiaryRS);
        primaryToSecTerRSMap.put(primaryRS, secAndTerSet);

        // Get the position of the current region server in the favored nodes list
        FavoredNodesPlan.Position favoredNodePosition =
            FavoredNodesPlan.getFavoredServerPosition(favoredNodes, currentRS);

        // Handle the non favored assignment.
        if (favoredNodePosition == null) {
          nonFavoredAssignedRegionList.add(region);
          continue;
        }
        // Increase the favored nodes assignment.
        this.favoredNodes[favoredNodePosition.ordinal()]++;
        totalFavoredAssignments++;

        // Summary the locality information for each favored nodes
        if (regionLocalityMap != null) {
          // Set the enforce locality as true;
          this.enforceLocality = true;

          // Get the region degree locality map
          Map<String, Float> regionDegreeLocalityMap =
              regionLocalityMap.get(region.getEncodedName());
          if (regionDegreeLocalityMap == null) {
            continue; // ignore the region which doesn't have any store files.
          }

          // Get the locality summary for each favored nodes
          for (FavoredNodesPlan.Position p : FavoredNodesPlan.Position.values()) {
            ServerName favoredNode = favoredNodes.get(p.ordinal());
            // Get the locality for the current favored nodes
            Float locality = regionDegreeLocalityMap.get(favoredNode.getHostname());
            if (locality != null) {
              this.favoredNodesLocalitySummary[p.ordinal()] += locality;
            }
          }

          // Get the locality summary for the current region server
          Float actualLocality = regionDegreeLocalityMap.get(currentRS.getHostname());
          if (actualLocality != null) {
            this.actualLocalitySummary += actualLocality;
          }
        }
      } catch (Exception e) {
        LOG.error(
            "Cannot verify the region assignment for region "
                + ((region == null) ? " null " : region.getRegionNameAsString())
                + "because of "
                + e);
      }
    }

    float dispersionScoreSummary = 0;
    float dispersionNumSummary = 0;
    // Calculate the secondary score for each primary region server
    for (Map.Entry<ServerName, Integer> entry : primaryRSToRegionCounterMap.entrySet()) {
      ServerName primaryRS = entry.getKey();
      Integer regionsOnPrimary = entry.getValue();

      // Process the dispersion number and score
      float dispersionScore = 0;
      int dispersionNum = 0;
      if (primaryToSecTerRSMap.get(primaryRS) != null && regionsOnPrimary.intValue() != 0) {
        dispersionNum = primaryToSecTerRSMap.get(primaryRS).size();
        dispersionScore = dispersionNum / ((float) regionsOnPrimary.intValue() * 2);
      }
      // Update the max dispersion score
      if (dispersionScore > this.maxDispersionScore) {
        this.maxDispersionScoreServerSet.clear();
        this.maxDispersionScoreServerSet.add(primaryRS);
        this.maxDispersionScore = dispersionScore;
      } else if (dispersionScore == this.maxDispersionScore) {
        this.maxDispersionScoreServerSet.add(primaryRS);
      }

      // Update the max dispersion num
      if (dispersionNum > this.maxDispersionNum) {
        this.maxDispersionNumServerSet.clear();
        this.maxDispersionNumServerSet.add(primaryRS);
        this.maxDispersionNum = dispersionNum;
      } else if (dispersionNum == this.maxDispersionNum) {
        this.maxDispersionNumServerSet.add(primaryRS);
      }

      // Update the min dispersion score
      if (dispersionScore < this.minDispersionScore) {
        this.minDispersionScoreServerSet.clear();
        this.minDispersionScoreServerSet.add(primaryRS);
        this.minDispersionScore = dispersionScore;
      } else if (dispersionScore == this.minDispersionScore) {
        this.minDispersionScoreServerSet.add(primaryRS);
      }

      // Update the min dispersion num
      if (dispersionNum < this.minDispersionNum) {
        this.minDispersionNumServerSet.clear();
        this.minDispersionNumServerSet.add(primaryRS);
        this.minDispersionNum = dispersionNum;
      } else if (dispersionNum == this.minDispersionNum) {
        this.minDispersionNumServerSet.add(primaryRS);
      }

      dispersionScoreSummary += dispersionScore;
      dispersionNumSummary += dispersionNum;
    }

    // Update the avg dispersion score
    if (primaryRSToRegionCounterMap.keySet().size() != 0) {
      this.avgDispersionScore =
          dispersionScoreSummary / (float) primaryRSToRegionCounterMap.keySet().size();
      this.avgDispersionNum =
          dispersionNumSummary / (float) primaryRSToRegionCounterMap.keySet().size();
    }

    // Fill up the most loaded and least loaded region server information
    for (Map.Entry<ServerName, Integer> entry : serverToHostingRegionCounterMap.entrySet()) {
      ServerName currentRS = entry.getKey();
      int hostRegionCounter = entry.getValue().intValue();

      // Update the most loaded region server list and maxRegionsOnRS
      if (hostRegionCounter > this.maxRegionsOnRS) {
        maxRegionsOnRS = hostRegionCounter;
        this.mostLoadedRSSet.clear();
        this.mostLoadedRSSet.add(currentRS);
      } else if (hostRegionCounter == this.maxRegionsOnRS) {
        this.mostLoadedRSSet.add(currentRS);
      }

      // Update the least loaded region server list and minRegionsOnRS
      if (hostRegionCounter < this.minRegionsOnRS) {
        this.minRegionsOnRS = hostRegionCounter;
        this.leastLoadedRSSet.clear();
        this.leastLoadedRSSet.add(currentRS);
      } else if (hostRegionCounter == this.minRegionsOnRS) {
        this.leastLoadedRSSet.add(currentRS);
      }
    }

    // and total region servers
    this.totalRegionServers = serverToHostingRegionCounterMap.keySet().size();
    this.avgRegionsOnRS =
        (totalRegionServers == 0) ? 0 : (totalRegions / (float) totalRegionServers);
    // Set the isFilledUp as true
    isFilledUp = true;
  }
  /**
   * Use this to project the dispersion scores
   *
   * @param tableName
   * @param snapshot
   * @param newPlan
   */
  public void fillUpDispersion(
      TableName tableName, SnapshotOfRegionAssignmentFromMeta snapshot, FavoredNodesPlan newPlan) {
    // Set the table name
    this.tableName = tableName;
    // Get all the regions for this table
    List<HRegionInfo> regionInfoList = snapshot.getTableToRegionMap().get(tableName);
    // Get the total region num for the current table
    this.totalRegions = regionInfoList.size();
    FavoredNodesPlan plan = null;
    if (newPlan == null) {
      plan = snapshot.getExistingAssignmentPlan();
    } else {
      plan = newPlan;
    }
    // Get the region to region server mapping
    Map<ServerName, Integer> primaryRSToRegionCounterMap = new HashMap<ServerName, Integer>();
    Map<ServerName, Set<ServerName>> primaryToSecTerRSMap =
        new HashMap<ServerName, Set<ServerName>>();

    // Check the favored nodes and its locality information
    // Also keep tracker of the most loaded and least loaded region servers
    for (HRegionInfo region : regionInfoList) {
      try {
        // Get the favored nodes from the assignment plan and verify it.
        List<ServerName> favoredNodes = plan.getFavoredNodes(region);
        if (favoredNodes == null
            || favoredNodes.size() != FavoredNodeAssignmentHelper.FAVORED_NODES_NUM) {
          regionsWithoutValidFavoredNodes.add(region);
          continue;
        }
        // Get the primary, secondary and tertiary region server
        ServerName primaryRS = favoredNodes.get(FavoredNodesPlan.Position.PRIMARY.ordinal());
        ServerName secondaryRS = favoredNodes.get(FavoredNodesPlan.Position.SECONDARY.ordinal());
        ServerName tertiaryRS = favoredNodes.get(FavoredNodesPlan.Position.TERTIARY.ordinal());

        // Update the primary rs to its region set map
        Integer regionCounter = primaryRSToRegionCounterMap.get(primaryRS);
        if (regionCounter == null) {
          regionCounter = Integer.valueOf(0);
        }
        regionCounter = regionCounter.intValue() + 1;
        primaryRSToRegionCounterMap.put(primaryRS, regionCounter);

        // Update the primary rs to secondary and tertiary rs map
        Set<ServerName> secAndTerSet = primaryToSecTerRSMap.get(primaryRS);
        if (secAndTerSet == null) {
          secAndTerSet = new HashSet<ServerName>();
        }
        secAndTerSet.add(secondaryRS);
        secAndTerSet.add(tertiaryRS);
        primaryToSecTerRSMap.put(primaryRS, secAndTerSet);
      } catch (Exception e) {
        LOG.error(
            "Cannot verify the region assignment for region "
                + ((region == null) ? " null " : region.getRegionNameAsString())
                + "because of "
                + e);
      }
    }
    float dispersionScoreSummary = 0;
    float dispersionNumSummary = 0;
    // Calculate the secondary score for each primary region server
    for (Map.Entry<ServerName, Integer> entry : primaryRSToRegionCounterMap.entrySet()) {
      ServerName primaryRS = entry.getKey();
      Integer regionsOnPrimary = entry.getValue();

      // Process the dispersion number and score
      float dispersionScore = 0;
      int dispersionNum = 0;
      if (primaryToSecTerRSMap.get(primaryRS) != null && regionsOnPrimary.intValue() != 0) {
        dispersionNum = primaryToSecTerRSMap.get(primaryRS).size();
        dispersionScore = dispersionNum / ((float) regionsOnPrimary.intValue() * 2);
      }

      // Update the max dispersion num
      if (dispersionNum > this.maxDispersionNum) {
        this.maxDispersionNumServerSet.clear();
        this.maxDispersionNumServerSet.add(primaryRS);
        this.maxDispersionNum = dispersionNum;
      } else if (dispersionNum == this.maxDispersionNum) {
        this.maxDispersionNumServerSet.add(primaryRS);
      }

      // Update the min dispersion score
      if (dispersionScore < this.minDispersionScore) {
        this.minDispersionScoreServerSet.clear();
        this.minDispersionScoreServerSet.add(primaryRS);
        this.minDispersionScore = dispersionScore;
      } else if (dispersionScore == this.minDispersionScore) {
        this.minDispersionScoreServerSet.add(primaryRS);
      }

      // Update the min dispersion num
      if (dispersionNum < this.minDispersionNum) {
        this.minDispersionNumServerSet.clear();
        this.minDispersionNumServerSet.add(primaryRS);
        this.minDispersionNum = dispersionNum;
      } else if (dispersionNum == this.minDispersionNum) {
        this.minDispersionNumServerSet.add(primaryRS);
      }

      dispersionScoreSummary += dispersionScore;
      dispersionNumSummary += dispersionNum;
    }

    // Update the avg dispersion score
    if (primaryRSToRegionCounterMap.keySet().size() != 0) {
      this.avgDispersionScore =
          dispersionScoreSummary / (float) primaryRSToRegionCounterMap.keySet().size();
      this.avgDispersionNum =
          dispersionNumSummary / (float) primaryRSToRegionCounterMap.keySet().size();
    }
  }