Are Application Pools Generally Larger In IIS 8.5 vs IIS 7.5

Update: The original question was for Windows Server 2008, but the solution is easier for Windows Server 2008 R2 and Windows Server 2012 (and Windows 7 and 8). You can add the user through the NTFS UI by typing it in directly. The name is in the format of IIS APPPOOL\{app pool name}. For example: IIS APPPOOL\DefaultAppPool.

IIS APPPOOL\{app pool name}

Note: Per comments below, there are two things to be aware of:

• Enter the string directly into the "Select User or Group" and not in the search field.
• In a domain environment you need to set the Location to your local computer first.

Reference to Microsoft Docs article: Application Pool Identities > Securing Resources

Original response: (for Windows Server 2008) This is a great feature, but as you mentioned it's not fully implemented yet. You can add the app pool identity from the command prompt with something like icacls, then you can manage it from the GUI. For example, run something like this from the command prompt:

icacls c:\inetpub\wwwroot /grant "IIS APPPOOL\DefaultAppPool":(OI)(CI)(RX)

Then, in Windows Explorer, go to the wwwroot folder and edit the security permissions. You will see what looks like a group (the group icon) called DefaultAppPool. You can now edit the permissions.

However, you don't need to use this at all. It's a bonus that you can use if you want. You can use the old way of creating a custom user per app pool and assigning the custom user to disk. That has full UI support.

This SID injection method is nice because it allows you to use a single user but fully isolate each site from each other without having to create unique users for each app pool. Pretty impressive, and it will be even better with UI support.

Note: If you are unable to find the application pool user, check to see if the Windows service called Application Host Helper Service is running. It's the service that maps application pool users to Windows accounts.

I think that it is hard to recommend any schedule for recycling since that really depends on the business side, for example, is your site primarily US-based or is it globally accessed as well? In general I would recommend looking at your analytics and determine when its "safer" to perform the recycling.

In fact the reason IIS uses 29 hours as the default was to have more of a "sliding" time, since having a default of 24 would make it always recycle at the same time and depending on when the apppool start that could be your "top" customer time and then you would be stuck for that every day.

So really there is not a good answer other than determine for example that if your customer base tends to be low at 2:00 am then use that. And of course if you enable specific schedule, make sure that the recycling interval is set to 0.

Whatever you choose make sure you do not disable Overlapped recycling (the default) and that way the downtime is minimal since IIS will continue serving requests while getting the new AppPool ready. If you are using IIS 7.5 you could even use the Application Warmup feature (still in Beta) to warm up the apppool before it starts handling requests, that way you never have a "slow" response.