为什么 .NET Core HttpWebRequest 不能 KeepAlive

Question

HttpWebRequest creates a new connection for each request. Why not share one?

I've set the KeepAlive option to true.

test enviroment

WIN7 .net core2.1 and .net core3.0

using System;
using System.Net;
using System.Threading;

namespace Question {
    static void Test() {
        var uri = new Uri("https://stackoverflow.com/");
        var webRequest = (HttpWebRequest)WebRequest.Create(uri);

        webRequest.KeepAlive = true;

        using (var webResponse = (HttpWebResponse)webRequest.GetResponse()) {
            // nothing
        }
    }

    static void Main(string[] args) {
        while (true) {
            Test();

            Thread.Sleep(1000);
        }
    }
}

Answer 1

Microsoft wants everyone to use HttpClient even though the HttpWebRequest interface is a lot more intuitive for most simple cases.

They only implemented HttpWebRequest in .NET Core because .NET Standard requires it. And they didn't bother to do a thorough implementation to make things like KeepAlive work properly. The HttpWebReequest in .NET Core is a thin wrapper around HttpClient, creating a new connection for each call (which is exactly how you're NOT supposed to use HttpClient).

Here is a very good article about how Http connection pooling works in the various frameworks: https://www.stevejgordon.co.uk/httpclient-connection-pooling-in-dotnet-core