Question

我正在使用HttpListener作为简单的http服务器。我已经通过让HttpListener为每个请求返回字符串“OK”来对req / sec性能进行基准测试 - 这已达到每秒16,000个请求的限制。根据以下代码，我可以做些什么来进一步优化性能？或者我们是否达到Windows Http.sys的极限？

图片上传无效，这里是Visual Studio性能跟踪的链接：

VS Performance Trace

Public Class HTTPServer

    Shared Listener As HttpListener = New HttpListener

    Public Shared Sub Start()

        ServicePointManager.DefaultConnectionLimit = 500
        ServicePointManager.Expect100Continue = False
        ServicePointManager.MaxServicePoints = 500

        Listener.Prefixes.Add("http://localhost/")
        Listener.Start()

        For i As Integer = 1 To (System.Environment.ProcessorCount * 2)

            Dim NewThread As New System.Threading.Thread(AddressOf ListenerThread)
            NewThread.Priority = ThreadPriority.Normal
            NewThread.IsBackground = True
            NewThread.Start()

        Next

    End Sub



    Private Shared Sub ListenerThread()

        Dim SyncResult As IAsyncResult

        While True

            SyncResult = Listener.BeginGetContext(New AsyncCallback(AddressOf ListenerCallback), Listener)
            SyncResult.AsyncWaitHandle.WaitOne()

        End While

    End Sub



    Private Shared Sub ListenerCallback(ByVal StateObject As IAsyncResult)

        Dim Listener As HttpListener = DirectCast(StateObject.AsyncState, HttpListener)

        Dim Context As HttpListenerContext = Listener.EndGetContext(StateObject)
        Dim Request As HttpListenerRequest = Context.Request

        Dim Response As HttpListenerResponse = Context.Response

        Dim ResponseString As String = "OK"

        Dim Buffer As Byte() = System.Text.Encoding.UTF8.GetBytes(ResponseString)
        Response.ContentLength64 = Buffer.Length
        Dim OutputStream As System.IO.Stream = Response.OutputStream
        OutputStream.Write(Buffer, 0, Buffer.Length)

        OutputStream.Close()
        OutputStream.Dispose()

    End Sub

End Class

Answer 1

你可以做的一件事情只是调用Encoding.UTF8.GetBytes("OK")一次，而不是每次请求。我怀疑它会产生多大的影响，但是如果你在每个请求上都做同样的事情，那么你可能会以你需要的形式得到那个响应。

我还会使用Using语句而不是显式调用Close和Dispose。这不是一个表现的东西 - 只是一般的好习惯，以避免在有例外的情况下使用未关闭的流的问题。

实际上，你需要才能达到16K以上的QPS吗？你有没有弄清楚你是在受CPU限制还是IO限制？一旦你的程序需要在每个请求上真正做一些真正的工作，我想这会使你在这里做的任何微观优化相形见绌。

HttpListener性能优化

1 个答案: