public static TableDescriptor getSystemTableDescriptor(Configuration conf) {
    TableDescriptorBuilder builder = TableDescriptorBuilder.newBuilder(getTableName(conf));

    ColumnFamilyDescriptorBuilder colBuilder =
      ColumnFamilyDescriptorBuilder.newBuilder(SESSIONS_FAMILY);

    colBuilder.setMaxVersions(1);
    Configuration config = HBaseConfiguration.create();
    int ttl = config.getInt(BackupRestoreConstants.BACKUP_SYSTEM_TTL_KEY,
      BackupRestoreConstants.BACKUP_SYSTEM_TTL_DEFAULT);
    colBuilder.setTimeToLive(ttl);

    ColumnFamilyDescriptor colSessionsDesc = colBuilder.build();
    builder.setColumnFamily(colSessionsDesc);

    colBuilder = ColumnFamilyDescriptorBuilder.newBuilder(META_FAMILY);
    colBuilder.setTimeToLive(ttl);
    builder.setColumnFamily(colBuilder.build());
    return builder.build();
  }
Get backup system table descriptor
@return table's descriptor
hbase-backup/src/main/java/org/apache/hadoop/hbase/backup/impl/BackupSystemTable.java