clustering node on iisnode using nodeProcessCountPerApplication - azure

Question

I have a web app in Azure which is using node.js and socket.io, and I decided to use the clustering supported by IISNODE, using nodeProcessCountPerApplication as below in my web.config
<iisnode nodeProcessCountPerApplication="0" />
However, when I apply this, I got 500.1013 internal server error, which states:
Most likely causes:
IIS received the request; however, an internal error occurred during the processing of the request. The root cause of this error depends on which module handles the request and what was happening in the worker process when this error occurred.
IIS was not able to access the web.config file for the Web site or application. This can occur if the NTFS permissions are set incorrectly.
IIS was not able to process configuration for the Web site or application.
The authenticated user does not have permission to use this DLL.
The request is mapped to a managed handler but the .NET Extensibility Feature is not installed.
I looked for examples but couldn't find anything similar. I am wondering what I am doing wrong here. I want to be able to use all processors of my machine.
Thanks !

Answer 1

I was able to use all processors of my App Service plan by using the following web.config file.
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<system.webServer>
<webSocket enabled="false" />
<handlers>
<add name="iisnode" path="app.js" verb="*" modules="iisnode" />
</handlers>
<rewrite>
<rules>
<rule name="NodeInspector" patternSyntax="ECMAScript" stopProcessing="true">
<match url="^app.js\/debug[\/]?" />
</rule>
<rule name="StaticContent">
<action type="Rewrite" url="public{REQUEST_URI}" />
</rule>
<rule name="DynamicContent">
<conditions>
<add input="{REQUEST_FILENAME}" matchType="IsFile" negate="True" />
</conditions>
<action type="Rewrite" url="app.js" />
</rule>
</rules>
</rewrite>
<security>
<requestFiltering>
<hiddenSegments>
<remove segment="bin" />
</hiddenSegments>
</requestFiltering>
</security>
<httpErrors existingResponse="PassThrough" />
<iisnode watchedFiles="web.config;*.js" devErrorsEnabled="true" nodeProcessCountPerApplication="0" />
</system.webServer>
</configuration>
As you are using socket.io on Azure Web App, you'll also need to set Web sockets to On in the Azure portal. See Using socket.io-redis on azure web service.