摘要
Http / 2协议提供了在单个连接上复用多个请求的功能。这样可以更有效地使用连接-请参见https://http2.github.io/faq/#why-is-http2-multiplexed
我希望能够使用.Net Core HttpClient来实现此目的。我的测试(基于以下内容)表明请求与TCP连接的比例为1:1。
.Net Core HttpClient是否支持多路复用?如果是这样,如何实现?
到目前为止工作
我有一个示例应用程序(可以在here中找到存储库,带有以下代码;
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}");
}
这段代码产生以下结果(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
从Wireshark中可以看到已经创建了2个连接-每个连接都必须经过TLS设置;
如果HttpClient复用请求,我希望看到一个连接(1个端口,1个握手等)。
最佳答案
我想我有答案(尽管肯定会重视反馈);
我上面的代码的问题在于,HttpClient在有机会为request1创建TCP连接之前就已经收到了request2。因此,就HttpClient而言,不存在要进行多路复用的现有连接。
但是,如果我创建一个初始请求(下面的request0)并允许HttpClient打开连接,则后续请求(1和2)将使用该现有连接。
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}");
}
还有Wireshark证明(仅1个端口,1个握手):
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,任何反馈都非常感谢。