How to increase timeout of Azure App Service for my ASP.NET Core 2.0 API

问题

I have an ASP.NET Core 2.0 API I am deploying to an Azure App Service. This has been working fine until recently when I had to process a request that took longer than 2 minutes to complete and I got a 502 Bad Gateway stating

"The specified CGI application encountered an error and the server terminated the process". 

This consistently happens when I hit the 2 minute mark on this process.

My diagnostic logfile says

018-05-25 02:07:01.462 +00:00 [Error] Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware: An unhandled exception has occurred while executing the request
System.Threading.Tasks.TaskCanceledException: A task was canceled.

I am working on the assumption that this is a timeout issue because it is always at the 2 minute mark and I know the request takes more than 2 minutes to complete. So I was looking into how to increase the timeout and found some posts on SO that talked about using an applicationHost.xdt file, placing it in the root of the Site folder for the site. I am using this XML;

<?xml version="1.0"?>
<configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">
  <system.applicationHost>
    <webLimits xdt:Transform="SetAttributes(connectionTimeout)" connectionTimeout="00:05:00" />
  </system.applicationHost>
</configuration>

When I upload it, using Kudu debug console, to the root of the Site folder for my deployment slot I am using to test my API and then look at the transform file, I see the following;

2018-05-24T19:34:19 Start 'site' site extension transform
2018-05-24T19:34:19 StartSection Executing SetAttributes (transform line 4, 16)
2018-05-24T19:34:19 on /configuration/system.applicationHost/webLimits
2018-05-24T19:34:19 Applying to 'webLimits' element (no source line info)
2018-05-24T19:34:19 Set 'connectionTimeout' attribute
2018-05-24T19:34:19 Set 1 attributes
2018-05-24T19:34:19 EndSection Done executing SetAttributes
2018-05-24T19:34:19 Successful 'D:\home\site\applicationHost.xdt' site extension transform

which to me looks like it successfully applied the XDT transform.

However even after restarting the base App Service and the related deployment slot. I am still getting the error.

So, am I using the wrong timeout setting?

When I look at the web.config file in my slots sites/wwwroot folder, it contains only this...

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <system.webServer>
    <handlers>
      <add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModule" resourceType="Unspecified" />
    </handlers>
    <aspNetCore processPath="dotnet" arguments=".\Mypp.dll" 
stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" />
  </system.webServer> 

I expected to see the information about the connectiontimeout that was in the XDT file I applied. So, perhaps this is not the right web.config file?

I am not an Azure expert and at this point, I feel like I am wasting time so I wanted to check an see if anyone has any suggestions.

回答1:

requestTimeout:

Specifies the duration for which the ASP.NET Core Module waits for a response from the process listening on %ASPNETCORE_PORT%.

In versions of the ASP.NET Core Module that shipped with the release of ASP.NET Core 2.0 or earlier, the requestTimeout must be specified in whole minutes only, otherwise it defaults to 2 minutes.

You could try to add the requestTimeout="00:20:00 in web.config in your slots sites/wwwroot folder.

<aspNetCore
  requestTimeout="00:20:00"
  processPath="%LAUNCHER_PATH%"
  arguments="%LAUNCHER_ARGS%"
  stdoutLogEnabled="false"
  stdoutLogFile=".\logs\stdout">
  <environmentVariables>
    <environmentVariable name="ASPNETCORE_ENVIRONMENT" value="staging" /> <!-- value could be "development", "staging" or "production"-->
  </environmentVariables>
</aspNetCore>

For more details, you could refer to this article to learn about ASP.NET Core Module configuration reference

来源：https://stackoverflow.com/questions/50520779/how-to-increase-timeout-of-azure-app-service-for-my-asp-net-core-2-0-api