你能用.Net Core HttpClient实现Http/2多路复用吗？

Question

摘要

Http/2协议提供了通过单个连接复用多个请求的能力.这样可以更有效地使用连接 - 请参阅https://http2.github.io/faq/#why-is-http2-multiplexed

我希望能够使用.Net Core HttpClient来实现这一目标.然而,我的测试(基于以下内容)表明对TCP连接的请求比率为1:1.

在.Net Core HttpClient下是否支持多路复用？如果是这样,它是如何实现的？

到目前为止工作

我有一个示例应用程序(可以在这里找到repo ,代码如下;

using (var httpClient = new HttpClient())
{
   var request1 = new HttpRequestMessage(HttpMethod.Get, "https://www.google.com");
   request1.Version = new Version(2, 0);

   var request2 = new HttpRequestMessage(HttpMethod.Get, "https://www.google.com");
   request2.Version = new Version(2, 0);

   var task1 = httpClient.SendAsync(request1);
   var task2 = httpClient.SendAsync(request2);

   Task.WaitAll(task1, task2);

   var response1 = task1.Result;
   var response2 = task2.Result;

   Console.WriteLine($"Response 1 - Http Version: {response1.Version}, Http Status Code: {response1.StatusCode}");
   Console.WriteLine($"Response 2 - Http Version: {response2.Version}, Http Status Code: {response2.StatusCode}");
}

此代码产生以下结果(所以我知道正在使用Http/2);

Response 1 - Http Version: 2.0, Http Status Code: OK
Response 2 - Http Version: 2.0, Http Status Code: OK

我从Wireshark可以看到已经创建了2个连接 - 每个连接都需要通过TLS设置;

如果HttpClient多路复用请求,我希望看到一个连接(1个端口,1个握手等).

Answer 1

我想我有答案(虽然肯定会重视反馈);

上面代码的问题是HttpClient正在接收request2,因为它有机会为request1创建TCP连接.因此,就HttpClient而言,没有与Multiplex的现有连接.

但是,如果我创建了一个初始请求(下面的request0)并允许HttpClient打开连接,则后续请求(1和2)使用该现有连接.

代码:

using (var httpClient = new HttpClient())
{
   // Setup first connection
   var request0 = new HttpRequestMessage(HttpMethod.Get, "https://www.google.com");
   request0.Version = new Version(2, 0);

   var task0 = httpClient.SendAsync(request0);
   var response0 = task0.Result;

   Console.WriteLine($"Response 0 - Http Version: {response0.Version}, Http Status Code: {response0.StatusCode}");

   // Now send the multiplexed requests
   var request1 = new HttpRequestMessage(HttpMethod.Get, "https://www.google.com");
   request1.Version = new Version(2, 0);

   var request2 = new HttpRequestMessage(HttpMethod.Get, "https://www.google.com");
   request2.Version = new Version(2, 0);

   var task1 = httpClient.SendAsync(request1);
   var task2 = httpClient.SendAsync(request2);

   Task.WaitAll(task1, task2);

   var response1 = task1.Result;
   var response2 = task2.Result;

   Console.WriteLine($"Response 1 - Http Version: {response1.Version}, Http Status Code: {response1.StatusCode}");
   Console.WriteLine($"Response 2 - Http Version: {response2.Version}, Http Status Code: {response2.StatusCode}");
}

和Wireshark证明(只有1个端口,1次握手):

我将继续进行进一步的研究,但这似乎是一个胜利者.如上所述,任何反馈都非常赞赏.