想知道是否有人可以提供一个令人信服的解释，在流水线环境下，http 1.1是半双工还是全双工？据我所知，在客户端得到响应之前，可以通过同一个持久连接发送多个请求。那么，这是否意味着服务器可以在客户端发送新请求时响应上一个请求？
最佳答案
让我们看看标准，在这种情况下RFC-2616。我们在第8.1.1段中发现，持续连接：
- 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.
稍后在文档中：
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.
在这两种情况下，都清楚地说明了客户端可以发送请求而无需等待响应，我认为可以安全地声明http 1.1支持全双工。
编辑：在取代RFC-2616的RFC集合的RFC-7230中，此语句变为：
A client that supports persistent connections MAY "pipeline" its
requests (i.e., send multiple requests without waiting for each
response). A server MAY process a sequence of pipelined requests in
parallel if they all have safe methods (Section 4.2.1 of [RFC7231]),
but it MUST send the corresponding responses in the same order that
the requests were received.