ASP.NET Processmodel Configuration Optimization

Question

A regular ASP.NET installation will create machine.config with the following configuration:

<system.web>
    <processModel autoConfig="true" />

I would like to override few properties values in web.config like:

<system.web>
   <processModel 
     maxWorkerThreads="100" 
     maxIoThreads="100" 
     minWorkerThreads="40" 
     minIoThreads="30" 
     memoryLimit="60" 
   />

I would like to know that whether i have to write all default properties inside web.config or it will automatically take other default properties of processmodel from machine.config?

Following are the properties of processmodel

<processModel 
   enable="true|false"
   timeout="hrs:mins:secs|Infinite" 
   idleTimeout="hrs:mins:secs|Infinite"
   shutdownTimeout="hrs:mins:secs|Infinite"
   requestLimit="num|Infinite"
   requestQueueLimit="num|Infinite"
   restartQueueLimit="num|Infinite"
   memoryLimit="percent"
   webGarden="true|false"
   cpuMask="num"
   userName="{username}"
   password="{secure password}"
   logLevel="All|None|Errors"
   clientConnectedCheck="hrs:mins:secs|Infinite"
   comAuthenticationLevel="Default|None|Connect|Call| 
               Pkt|PktIntegrity|PktPrivacy"
   comImpersonationLevel="Default|Anonymous|Identify|
               Impersonate|Delegate"
   responseDeadlockInterval="hrs:mins:secs|Infinite"
   responseRestartDeadlockInterval="hrs:mins:secs|Infinite"
   autoConfig="true|false"
   maxWorkerThreads="num"
   maxIoThreads="num"
   minWorkerThreads="num"
   minIoThreads="num"
   serverErrorMessageFile="" 
   pingFrequency="Infinite" 
   pingTimeout="Infinite" 
   maxAppDomains="2000"
/>

Answer 1

Machine.config is always inherited.

From MSDN:

Multiple configuration files, all named Web.config, can appear in multiple directories on an ASP.NET Web application server. Each Web.config file applies configuration settings to its own directory and all child directories below it. Configuration files in child directories can supply configuration information in addition to that inherited from parent directories, and the child directory configuration settings can override or modify settings defined in parent directories. The root configuration file named systemroot\Microsoft.NET\Framework\versionNumber\CONFIG\Machine.config provides ASP.NET configuration settings for the entire Web server.

Answer 2

It seems we cannot override the processModel settings in web.config as per the below link.

http://msdn.microsoft.com/en-us/library/ms178685.aspx

EDIT : I didn't read the comments. We can set MachineToApplication value which requires machine reboot it seems. Any idea what will be the side effects?

Thanks.