长连接处理同样的内容，为什么golang RPC over http要比Http协议更快呢

1、golang基于http协议实现的RPC
2、http长连接（此处不考虑http2.0）
二者的性能比较

8.1 Persistent Connections

8.1.1 Purpose

   ...

   Persistent HTTP connections have a number of advantages:

      ...
      
      - HTTP requests and responses can be pipelined on a connection.
        Pipelining allows a client to make multiple requests without
        waiting for each response, allowing a single TCP connection to
        be used much more efficiently, with much lower elapsed time.

      ...

虽然Http1.1协议规定客户端可以在长连接中，无需等待服务器响应，复用连接通道连续发送多个请求以提高效率

8.1.2.2 Pipelining

   A client that supports persistent connections MAY "pipeline" its
   requests (i.e., send multiple requests without waiting for each
   response). A server MUST send its responses to those requests in the
   same order that the requests were received.

从pipeling的要求来看， 服务端必须按照request的顺序返回response ， 这将大大的影响服务器处理请求的效率

猜测golang的net/rpc只是复用了tcp连接通道，而没有完全遵循http1.1协议。按双向发送数据实现，从测试性能上看，比纯粹的http长连接高出一倍左右就合理了。

测试数据如下：
单机基于ab测试100000请求， 发送数据都很小，可以忽略json和protobuf解码效率的差异

从QPS上比较， 基于http和基于json的rpc的性能没有太大差别， 都比http长连接高一倍左右

golang代码实现，参考：https://studygolang.com/articles/14336