我有一个ASP.NET WebApi自托管应用程序。 HttpSelfHostConfiguration
配置如下
HttpSelfHostConfiguration config = new HttpSelfHostConfiguration("http://0.0.0.0:54781")
{
TransferMode = TransferMode.StreamedResponse,
MaxConcurrentRequests = 1000,
SendTimeout = TimeSpan.FromMinutes(60),
};
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "{controller}",
defaults: new { @controller = "Default" }
);
HttpSelfHostServer server = new HttpSelfHostServer(config);
server.OpenAsync().Wait();
for (;;)
{
int workerThreads, completionPortThreads;
ThreadPool.GetAvailableThreads(out workerThreads, out completionPortThreads);
Console.WriteLine("Available Completion Port Threads = {0};", completionPortThreads);
Console.Out.Flush();
Thread.Sleep(2000);
}
有一个动作接受HTTP GET请求,如下所示
public class DefaultController : ApiController
{
public HttpResponseMessage GET()
{
Console.WriteLine("Receive HTTP GET request");
Func<Stream, HttpContent, TransportContext, Task> func = (stream, httpContent, transportContext) =>
{
return Monitor(httpContent, stream);
};
HttpResponseMessage response = Request.CreateResponse();
response.StatusCode = HttpStatusCode.OK;
response.Content = new PushStreamContent(func, new MediaTypeHeaderValue("text/plain"));
return response;
}
async Task Monitor(HttpContent httpContent, Stream stream)
{
try
{
using (StreamWriter sw = new StreamWriter(stream, new UTF8Encoding(false)))
{
for (;;)
{
sw.WriteLine(Guid.NewGuid().ToString());
sw.Flush();
await Task.Delay(1000);
}
}
}
catch (CommunicationException ce)
{
HttpListenerException ex = ce.InnerException as HttpListenerException;
if (ex != null)
{
Console.WriteLine("HttpListenerException occurs, error code = {0}", ex.ErrorCode);
}
else
{
Console.WriteLine("{0} occurs : {1}", ce.GetType().Name, ce.Message);
}
}
catch (Exception ex)
{
Console.WriteLine("{0} occurs : {1}", ex.GetType().Name, ex.Message);
}
finally
{
stream.Close();
stream.Dispose();
httpContent.Dispose();
Console.WriteLine("Dispose");
}
}
}
打开网址http://127.0.0.1:54781/
,我看到渐进式响应即将发生。
但是如果客户端在服务器发送响应时终止连接,则完成端口线程将被占用并且永不释放。
它可以通过耗尽完成端口线程池来降低应用程序。
答案 0 :(得分:0)
更改为OWIN自托管后,此问题消失。这似乎是System.Web.Http.SelfHost
这是更新的代码:
class Program
{
static void Main(string[] args)
{
var server = WebApp.Start<Startup>(url: "http://*:54781");
for (;;)
{
int workerThreads, completionPortThreads;
ThreadPool.GetAvailableThreads(out workerThreads, out completionPortThreads);
Console.WriteLine("Worker Threads = {0}; Available Completion Port Threads = {1};", workerThreads, completionPortThreads);
Console.Out.Flush();
Thread.Sleep(2000);
}
}
}
public class Startup
{
// This code configures Web API. The Startup class is specified as a type
// parameter in the WebApp.Start method.
public void Configuration(IAppBuilder appBuilder)
{
// Configure Web API for self-host.
HttpConfiguration config = new HttpConfiguration();
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "{controller}",
defaults: new { @controller = "Default" }
);
appBuilder.UseWebApi(config);
}
}
答案 1 :(得分:0)
对于其他人来到这篇文章,System.Web.Http.SelfHost
中存在类似的问题,默认情况下使用CPU内核* 100个线程,这与默认的ThreadPool限制相同,因为Mono预创建所有线程
解决此问题的最简单方法是将MONO_THREADS_PER_CPU
环境变量设置为大于1的值,或者在运行Mono应用程序时使用--server
标志。