I have an asp 2.0 web.
It very eagerly displays this error:
(nothing shows up for the users)

Message:

The remote host closed the connection. The error code is 0x80072746.

Stacktrace:

at System.Web.Hosting.ISAPIWorkerRequestInProcForIIS6.FlushCore(Byte[]
status, Byte[] header, Int32 keepConnected, Int32 totalBodySize, Int32
numBodyFragments, IntPtr[] bodyFragments, Int32[] bodyFragmentLengths, Int32
doneWithSession, Int32 finalStatus, Boolean& async)

at System.Web.Hosting.ISAPIWorkerRequest.FlushCachedResponse(Boolean isFinal)

at System.Web.Hosting.ISAPIWorkerRequest.FlushResponse(Boolean finalFlush)
at System.Web.HttpResponse.Flush(Boolean finalFlush)

at System.Web.HttpWriter.WriteFromStream(Byte[] data, Int32 offset, Int32 size)

at System.Web.HttpResponseStream.Write(Byte[] buffer, Int32 offset, Int32 count)

at Nymi.Logo.ProcessRequest(HttpContext context)

at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()

at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean&completedSynchronously)



I have googled and this error is not reffered to much.

One solution is on every affected page set Page:Buffer="false"

One other is in the .ashx set IsReusable = "false"


Neither works for me.


I do would appreciate further ideas.



/k

As for the "remote host closed connection exception...", it indicates the response of the ASP.NET worker thread has been closed due to some certain
internal exception when flushing data out to the response stream. And from the internal diassemblied code, this error message is a general exception
message and we can not get the detailed cause from it or the related exception handling code logic.

Based on my experience, there is several possible things can cause the
httprequest connection be closed unexpectedly.

1. when establshing https/ssl connection
2. when upload or flush out large data content cause the request timeout or exceed the max allowed request length.

For your scenario, #1 is not likely the cause. I'm wondering how often does the error occur in your converted ASP.NET 2.0 applicaiton. Also, is
the problem occuring when the page is flushing out large data content that is time consuming? For the ASP.NET request, there is max value setting for
the request length and executiontime, I'm not sure whether your application or server has ever manualy modified that value in 1.X(in machine.config),
and after converted to 2.0, the application will inherit 2.0's global configuration which hasn't changed the value accordingly? The
executionTimeout and other httpRuntime related setting are in the following configuration element:
http://msdn2.microsoft.com/en-us/lib...41(VS.80).aspx

If you are using the Application_Error event to handle the unexpected exception, you can consider record the page that cause the problem. Thus,
we can check whether the problem occurs on some page which has some common setting or code logic.

Anyway, since this is a concrete project specific issue, it would be more helpful if we can generate a simplified page which can reproduce the
behavior.

I trap the error in Application_Error. The error occurs in all pages in the web.

The problem occurs in the production environment but not in the test environment.

I have compared the machine.config and they are identical.

All pages uses an .ashx to deliver a logo. 

I will try to reproduce the error on a simplified page. 

/k

 

I have reproduced the error with a simplified page.

If I have my .ashx in the page the error occurs, otherwise not.

The code in the .ashx below, can you spot my error?

 

<%

@ WebHandler Language="VB" Class="Apa.Logo" %>

Option

Strict On

Option

Explicit On

Imports

System

Imports

System.Web

Imports

System.Drawing

Imports

System.Drawing.Imaging

Imports

System.IO

Imports

System.Web.Caching

Namespace

Apa

 

Public Class Logo : Implements IHttpHandler

Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest

Dim imageID As String = context.Request.QueryString("Logo")

Dim cacheKey As String = context.Request.CurrentExecutionFilePath & ":" & imageID

Dim imageBytes As Byte()

Dim cachedImageBytes As Object = context.Cache.Get(cacheKey)

If Not cachedImageBytes Is Nothing Then

imageBytes = CType(cachedImageBytes, Byte())

Else

Dim bm As Bitmap = DirectCast(System.Web.HttpContext.GetGlobalResourceObject("HeaderImageRes", "Logo.gif"), Bitmap)

Dim stream As MemoryStream = New MemoryStream()

bm.Save(stream, ImageFormat.Gif)

stream.Close()

bm.Dispose()

imageBytes = stream.GetBuffer()

context.Cache.Add(cacheKey, imageBytes, Nothing, DateTime.MaxValue, New TimeSpan(2, 0, 0), CacheItemPriority.Normal, Nothing)

End If

context.Response.ContentType = "image/gif"

context.Response.Cache.SetCacheability(HttpCacheability.Public)

context.Response.BufferOutput = False

context.Response.OutputStream.Write(imageBytes, 0, imageBytes.Length)

End Sub

Public ReadOnly Property IsReusable() As Boolean Implements IHttpHandler.IsReusable

Get

Return False

End Get

End Property

End Class

End

Namespace

I have reproduced the error with a simplified page.

If I have my .ashx in the page the error occurs, otherwise not.

The code in the .ashx below, can you spot my error?

 

<%

@ WebHandler Language="VB" Class="Apa.Logo" %>

Option

Strict On

Option

Explicit On

Imports

System

Imports

System.Web

Imports

System.Drawing

Imports

System.Drawing.Imaging

Imports

System.IO

Imports

System.Web.Caching

Namespace

Apa

 

Public Class Logo : Implements IHttpHandler

Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest

Dim imageID As String = context.Request.QueryString("Logo")

Dim cacheKey As String = context.Request.CurrentExecutionFilePath & ":" & imageID

Dim imageBytes As Byte()

Dim cachedImageBytes As Object = context.Cache.Get(cacheKey)

If Not cachedImageBytes Is Nothing Then

imageBytes = CType(cachedImageBytes, Byte())

Else

Dim bm As Bitmap = DirectCast(System.Web.HttpContext.GetGlobalResourceObject("HeaderImageRes", "Logo.gif"), Bitmap)

Dim stream As MemoryStream = New MemoryStream()

bm.Save(stream, ImageFormat.Gif)

stream.Close()

bm.Dispose()

imageBytes = stream.GetBuffer()

context.Cache.Add(cacheKey, imageBytes, Nothing, DateTime.MaxValue, New TimeSpan(2, 0, 0), CacheItemPriority.Normal, Nothing)

End If

context.Response.ContentType = "image/gif"

context.Response.Cache.SetCacheability(HttpCacheability.Public)

context.Response.BufferOutput = False

context.Response.OutputStream.Write(imageBytes, 0, imageBytes.Length)

End Sub

Public ReadOnly Property IsReusable() As Boolean Implements IHttpHandler.IsReusable

Get

Return False

End Get

End Property

End Class

End

Namespace

Yes,I can repro the error message saying that the remote host closed the connection.Here are some readings about IHttpHandler for your reference.
http://discuss.joelonsoftware.com/default.asp?dotnet.12.323321.5
http://blogs.msdn.com/smourier/archive/2003/05/16/7125.aspx
http://www.vbinfozine.com/c/13_Download.vb.shtml
Wish the above can give you some helps.

Thanks for your answer.

My problem is that the handler works on four servers but not on the fifth, which unfortunately is the production box.

I have a case with MS on this matter. The question is "How to troubleshoot this?"

I'll post a solution when I've got one.

 

k

Try to take a look at this KB from Microsoft - http://support.microsoft.com/kb/307997/EN-US/
Wish it can give you some helps.

You can also debug an HTTP Handler (*.ashx) in ASP.NET 2.0 and try to solve the problem as the following link.
http://www.15seconds.com/Issue/060406.htm
Wish this can give you some helps.

Thanks for the tip.

 I read the 15seconds-article. I accessed the .ashx directly in the browser.

On the production machine the error occurs. On the test server it did not.

Sadly I have no opportunity debugging in production, and the error doesn't occur in any test environment. :-(

I also checked the app configuration which are identical on both servers.

/k

 

Solution found.

Contrary to http://weblogs.asp.net/shankun/archive/2004/08/16/215487.aspx

this must be set to true:  HttpContext.Response.BufferOutput = True

, otherwise chunking might occur and then the error .

 

/k