Created by: MRXLT
https://github.com/PaddlePaddle/Serving/pull/399 https://github.com/PaddlePaddle/Serving/pull/400 https://github.com/PaddlePaddle/Serving/pull/401 https://github.com/PaddlePaddle/Serving/pull/402 https://github.com/PaddlePaddle/Serving/pull/403