同时HttpWebRequests的最大数量 [英] Max number of concurrent HttpWebRequests
问题描述
我的压力测试一个web应用程序，并建立了一个窗口的测试程序，它旋转了多个线程，并发出每一个Web请求。
I'm stress testing a web app and have set up a windows test program that spins up a number of threads and sends out a web request on each one.
问题是我得到以下输出：
Problem is I get the following output:
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!
之类的，看起来像有一个最大的5个线程的，即使我创建100个像这样：
which sort of looks like there's a maximum of 5 threads, even if I create 100 as so:
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();
}
任何人都可以见识一下，什么是怎么回事？
Can anyone enlighten me as to what is going on?
感谢
编辑：如果作为建议我睡觉，而不是HttpWebRequest的5秒钟，然后我得到更多的线程射击，但没有那么多，因为我本来期望：
If as suggested I sleep for 5 seconds, instead of httpwebrequest, then I do get more threads firing but not as many as I would have expected:
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!
它仍然看起来像我只获得了首发的每一秒，这似乎慢浩浩荡荡向我2个线程。我想Console.WriteLine命令可能是一个问题？
It still looks like I'm only getting 2 threads starting every second, which seems mighty slow to me. I suppose the Console.WriteLine could be a problem?
编辑：我设置
ThreadPool.SetMinThreads(100, 4);
和
System.Net.ServicePointManager.DefaultConnectionLimit = 100;
和得到以下结果：
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
所以能够一大堆的Web请求的推出兼任。这似乎要排队（呼唤一个STA COM +服务器），所以这是我所期待的。
so was able to push out a whole lot of web requests concurrently. Which seemed to queue (calling out to an STA COM+ server) so that's what I expected.
感谢您的帮助
推荐答案
您请求任何机会去同一个主机是否所有（或大部分）？有在每个主机的内置限制。您可以在app.config中的system.Net connectionManagement 元素改变这一点。
Are all (or most) of your requests going to the same host by any chance? There's a built-in limit on a per-host basis. You can change this in app.config in the system.Net connectionManagement element.
另一件事是，线程池只斜了线程的数量逐步 - 它开始一个新的线程每半秒，IIRC。莫非是你看到了什么？尝试获得从方程式摆脱的HttpWebRequest - 只是睡了一两秒钟，而不是...
The other thing is that the thread pool only ramps up its number of threads gradually - it starts a new thread every half second, IIRC. Could that be what you're seeing? Try getting rid of HttpWebRequest from the equation - just sleep for a couple of seconds instead...
我怀疑后者的问题是一个你开始运行到，但第一个是要引起你的问题也是如此。
I suspect the latter problem is the one you're initially running into, but the first one is going to cause you problems as well.
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