public HashMap<String, Long> readRegionServerLastLogRollResult(String backupRoot)
    throws IOException {
    LOG.trace("read region server last roll log result to backup system table");

    Scan scan = createScanForReadRegionServerLastLogRollResult(backupRoot);

    try (Table table = connection.getTable(tableName);
      ResultScanner scanner = table.getScanner(scan)) {
      Result res;
      HashMap<String, Long> rsTimestampMap = new HashMap<>();
      while ((res = scanner.next()) != null) {
        res.advance();
        Cell cell = res.current();
        byte[] row = CellUtil.cloneRow(cell);
        String server = getServerNameForReadRegionServerLastLogRollResult(row);
        byte[] data = CellUtil.cloneValue(cell);
        rsTimestampMap.put(server, Bytes.toLong(data));
      }
      return rsTimestampMap;
    }
  }
Get the Region Servers log information after the last log roll from backup system table.
@param backupRoot root directory path to backup
@return RS log info
@throws IOException exception
hbase-backup/src/main/java/org/apache/hadoop/hbase/backup/impl/BackupSystemTable.java