public static byte[] generateUpstreamId() {
    byte[] upstreamId = new byte[ID_BYTE_LENGTH];
    String uuidStr = UUID.randomUUID().toString();
    for (int i = 0; i < ID_BYTE_LENGTH; i++) {
      upstreamId[i] = (byte) uuidStr.charAt(i);
    }
    return upstreamId;
  }
generate a upstream job id

@return four length bytes id
amoro-common/src/main/java/org/apache/amoro/utils/IdGenerator.java