ApplicationHost Helper Service – what does it do?

Another new thing about IIS7 is this new service called the ApplicationHost Helper.  This serves two main purposes:

  • Configuration history
  • Application Pool Account Mappings

Config History

This is the service that will make backups of your ApplicationHost.config file.  Which is very important in IIS7 as there is where all the settings for IIS7 now reside, instead of in the metabase.

You can force a backup to be created using the AppCmd tool.  Or you can use the Module here to add it to your Inetmgr.  This tool just calls into the ApplicationHost Service to make the backup.  The service will also back up the config file periodically on it’s own.  You will see that you have a \Inetpub\history folder.  This is where the service will place the backups when they are created.  To change how often it backs up the file, you can add a configHistory section to the ApplicationHost.config file using the settings from here.

Note: Once we hit the max amount of backups, we will start recycling the oldest ones, so if you need to keep a particular version, be sure to copy it to another, safe, location

If you like what you are reading, get it from the source:

AppPool Account Mappings

The other purpose of this service is to allow you to lock down your content directories using user-friendly names.  It allows you to use access control list (ACL) UI in Windows Explorer or the ICACLS command-line tool instead of using security identifiers (SID) to lock down the content.  This service maps the accounts to the SID.  This makes things much easier when it comes to locking down your content.  You can also take advantage of the new account that gets created for the AppPool to lock down the content if you’d like also, see my previous blog entry for info on how that gets created. 

If you stop this service, no backups will be made of your IIS settings and IIS won’t be able to map the accounts correctly.

kick it on

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