最大并发HttpWebRequests数

Question

我正在对一个Web应用程序进行压力测试,并设置了一个Windows测试程序,该程序可以旋转多个线程并在每个线程上发出Web请求.

问题是我得到以下输出:

01/09/09 11:34:04 Starting new HTTP request on 10
01/09/09 11:34:04 Starting new HTTP request on 11
01/09/09 11:34:04 Starting new HTTP request on 13
01/09/09 11:34:05 Starting new HTTP request on 14
01/09/09 11:34:05 Starting new HTTP request on 11
01/09/09 11:34:05 11 has finished!
01/09/09 11:34:05 Starting new HTTP request on 13
01/09/09 11:34:05 13 has finished!
01/09/09 11:34:05 Starting new HTTP request on 14
01/09/09 11:34:05 14 has finished!
01/09/09 11:34:05 Starting new HTTP request on 11
01/09/09 11:34:05 11 has finished!
01/09/09 11:34:05 Starting new HTTP request on 14
01/09/09 11:34:05 14 has finished!
01/09/09 11:34:05 Starting new HTTP request on 13
01/09/09 11:34:05 13 has finished!
01/09/09 11:34:05 Starting new HTTP request on 15
01/09/09 11:34:06 Starting new HTTP request on 11
01/09/09 11:34:06 11 has finished!
01/09/09 11:34:06 Starting new HTTP request on 14
01/09/09 11:34:06 14 has finished!

哪种看起来最多有5个线程,即使我这样创建100个:

int numberOfThreads = Convert.ToInt32(txtConcurrentThreads.Text);

    List<BackgroundWorker> workers = new List<BackgroundWorker>();

    for (int N = 0; N < numberOfThreads; N++)
    {

        BackgroundWorker worker = new BackgroundWorker();
        worker.DoWork += new DoWorkEventHandler(worker_DoWork);
        worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(worker_RunWorkerCompleted);
        workers.Add(worker);
    }


    foreach(BackgroundWorker worker in workers)
    {
        worker.RunWorkerAsync();
    }

任何人都可以告诉我发生了什么事吗？

谢谢

编辑:如果按照建议我睡了5秒,而不是httpwebrequest,那么我确实得到了更多的线程射击,但没有我想象的那么多:

01/09/09 11:56:14 Starting new HTTP request on 7
01/09/09 11:56:14 Starting new HTTP request on 11
01/09/09 11:56:15 Starting new HTTP request on 12
01/09/09 11:56:15 Starting new HTTP request on 13
01/09/09 11:56:16 Starting new HTTP request on 14
01/09/09 11:56:16 Starting new HTTP request on 15
01/09/09 11:56:17 Starting new HTTP request on 16
01/09/09 11:56:17 Starting new HTTP request on 17
01/09/09 11:56:18 Starting new HTTP request on 18
01/09/09 11:56:19 Starting new HTTP request on 7
01/09/09 11:56:19 7 has finished!
01/09/09 11:56:19 Starting new HTTP request on 11
01/09/09 11:56:19 11 has finished!
01/09/09 11:56:19 Starting new HTTP request on 19
01/09/09 11:56:20 Starting new HTTP request on 20
01/09/09 11:56:20 Starting new HTTP request on 12
01/09/09 11:56:20 12 has finished!

它仍然看起来我每秒只开始2个线程,这对我来说似乎很慢.我想Console.WriteLine可能有问题吗？

编辑:我设置

ThreadPool.SetMinThreads(100, 4); 

和

System.Net.ServicePointManager.DefaultConnectionLimit = 100;

并得到以下结果:

01/09/09 14:00:07 Starting new HTTP request on 11
01/09/09 14:00:07 Starting new HTTP request on 81
01/09/09 14:00:07 Starting new HTTP request on 82
01/09/09 14:00:07 Starting new HTTP request on 79
01/09/09 14:00:07 Starting new HTTP request on 83
01/09/09 14:00:07 Starting new HTTP request on 84
01/09/09 14:00:07 Starting new HTTP request on 85
01/09/09 14:00:07 Starting new HTTP request on 87
01/09/09 14:00:07 Starting new HTTP request on 88
...
01/09/09 14:00:07 84 has finished! Took 323.0323 milliseconds
01/09/09 14:00:08 88 has finished! Took 808.0808 milliseconds
01/09/09 14:00:08 96 has finished! Took 806.0806 milliseconds
01/09/09 14:00:08 94 has finished! Took 806.0806 milliseconds
01/09/09 14:00:08 98 has finished! Took 801.0801 milliseconds
01/09/09 14:00:08 80 has finished! Took 799.0799 milliseconds
01/09/09 14:00:08 86 has finished! Took 799.0799 milliseconds
01/09/09 14:00:08 92 has finished! Took 799.0799 milliseconds
01/09/09 14:00:08 100 has finished! Took 812.0812 milliseconds
01/09/09 14:00:08 82 has finished! Took 1010.101 milliseconds

因此能够同时推出大量的Web请求.这似乎排队(呼叫STA COM +服务器),这就是我的预期.

谢谢你的帮助

Answer 1

您的所有(或大多数)请求是否都有机会进入同一主机？每个主机有一个内置限制.您可以在system.Net connectionManagement元素的app.config中更改此设置.

另一件事是线程池只逐渐增加其线程数 - 它每半秒启动一个新线程,IIRC.这可能是你所看到的吗？尝试摆脱HttpWebRequest等式 - 只是睡了几秒钟而不是......

我怀疑后一个问题是你最初遇到的问题,但第一个问题也会引起你的问题.

Answer 2

同时传出HTTP连接的数量有限制.我认为你可以System.Net.ServicePointManager.DefaultConnectionLimit在创建HttpWebRequest对象之前使用static属性来控制它.

Answer 3

我对.NET Core的了解还很少。.NET Core 1中未包含ServicePointManager，但在版本2中似乎又包含了ServicePointManager。但是，对于HttpClient，您还可以这样设置最大连接数：

new HttpClient(new HttpClientHandler
                {
                    MaxConnectionsPerServer = 100
                })

Answer 4

如果我在 Windows 配置中写下面的标签，那么每次执行下面的代码时都会执行它。所以每次执行下面的代码时，我将被允许有最多 1000000 个并行请求/响应。

HttpWebRequest POSTRequest = (HttpWebRequest)WebRequest.Create("http://yahoo.com");

标签

<connectionManagement>
 <clear/>
 <add address="*" maxconnection="1000000" />
</connectionManagement>