Error -4077 ECONNRESET connection reset by peer

[anobaka]

environment:

• windows 2012 r2
• IIS8
• kestrel
• .net452
• web application
• redis distributed cache
• use session

exception:

info: Microsoft.AspNetCore.Server.Kestrel[14]
      Connection id "0HKUNP9IK98PK" communication error
      Microsoft.AspNetCore.Server.Kestrel.Internal.Networking.UvException: Error -4077 ECONNRESET connection reset by peer

reproduction: what I've done and what happend:

1. publish to production servers and configure the load balance.
2. configure domain forward to the ip of load balance.
3. use some special browser to access the website.
4. iis's 502 error page shows.

here's fail request log in iis:

MODULE_SET_RESPONSE_ERROR_STATUS

Warning
 ModuleName="AspNetCoreModule", Notification="EXECUTE_REQUEST_HANDLER", HttpStatus="502", HttpReason="Bad Gateway", HttpSubStatus="3", ErrorCode="2147954552", ConfigExceptionInfo="" 

It's very strange thing, the exception throwed only when all above conditions are met, and if one of them missed(eg. using local host settings instead of configuring the real domain forward to the ip of the lb, or using other browsers), the website can be accessed successfully.

Please help, some of our users are blocked by this. Thanks.

[guardrex]

@anobaka Move this over to https://github.com/aspnet/IISIntegration/issues to get more :eyes: on it and close it here. Wait. @Tratcher is watching here, and he might say this is a Kestrel thing.

[Tratcher]

Kestrel says IIS closed the connection (though it's unclear when in the request this happened). IIS says Kestrel failed to respond in a timely fashion, which may be why it closed the connection. How long was the request running before this happened? What was the request trying to do?

[anobaka]

@Tratcher The response time is less than 1 second, even than 100 ms, it just responses immediately. The request is just to access the homepage of website.

You can try this:

1. install QQBrowser in IOS 9.3.x.(Chinese version, called "QQ浏览器" in Chinese)
2. access http://ahstest.aihuishou.com in QQBrowser.
3. the 502 response shows.

My tests:

• I tried using that browser to access the website by real machine ip, and it worked.
• I tried using that browser to access the website by load balance ip, and it worked, but some statis files are not found(404), why?.
• I tried using that browser to access the website by domain, and it failed.
• I tried using other browsers, it worked.

My attempts:

• I think there's something wired in the HTTP request. Maybe some non-ascii characters in user-agent or other fields. I tried using urlrewrite to urlencode user-agent if it's invalid, but it not works.
• I also tried capturing the http request sended by that browser, but when there's a proxy(for capturing the request) between QQBrwoser and our website, it accesses the website successfully.
• I'm trying using urlrewrite to urlencode more http fields if it's invalid.

Any idea? Thanks.

[Tratcher]

Use Microsoft Message Analyzer to trace the packets coming into the server and see what the raw header values are. https://www.microsoft.com/en-us/download/details.aspx?id=44226

[anobaka]

Thanks, it's powerful. Here's the packets.502.tar.gz MessageNumber 28868 & 808129 are the 502 responded requests sended by some special browsers. MessageNumber 633002 is the 200 responded request sended by other browsers.

Update It maybe the x-forwarded-for header, when I add a comma into x-forwarded-for header, it returns 502, but 200 for other special characters like . ?.

Update2 I removed the x-forwarded-for(F5XFFHttpModule.dll) module in IIS I added before, it seems to work.

[Tratcher]

@anobaka glad you found it, is this good to close now?

[anobaka]

@Tratcher , of course, thanks for your help.