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<String, List<ServerName>> assignmentMap = new TreeMap<>(plan.getAssignmentMap());

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

      String serverList = FavoredNodeAssignmentHelper.getFavoredNodesAsString(entry.getValue());
      String regionName = entry.getKey();
      LOG.info("Region: " + regionName);
      LOG.info("Its favored nodes: " + serverList);
    }
    LOG.info("========== Finish to print the assignment plan ================");
  }
Print the assignment plan to the system output stream
hbase-server/src/main/java/org/apache/hadoop/hbase/master/RegionPlacementMaintainer.java