We currently have about 600 .net sites in a single app pool. We're starting to get out of memory exceptions and have to recycle the app pool to fix the problem.

I know it's generally a good idea to have separate app pools per site, but i'm not sure it's realistic to have 600+ app pools on the same server. We will also be adding 30+ new sites per month.

My questions are:

  1. How many sites should i have per app pool
  2. How many app pools should i stick to per server (specifically Windows Server 2008 standard, Dual Xeon 2.53, 8 gigs of ram, 64 bit)

Also, these sites are load balanced between two servers.

migrated from stackoverflow.com Sep 15 '10 at 10:29

This question came from our site for professional and enthusiast programmers.

  • 1
    Some poor people here pay for advertising feature that they never get :). Its very sad to see that you try to keep 600 sites on a single computer. If any of this site is not just some pages then he face a lot of problems. – Aristos Sep 13 '10 at 13:20

Don't need to much thought or search the technical data - You are out of limits.

In general there are very simple sites that after one compile they no need many thinks, but there are also some complex site that have probably database access or other data processing that need some resource from your computer.

There are also the case that one site from your 600 have a serious bug, or eat a lot of memory and affect the rest 599.

One site from all with a close loop function can crash you any time :)

Also the pool have make at least 600 directories on your root disk, where your os lives and this is an issue also... a lot of read/write the compilers, the email that you have give with your sites, the iis log files, the cache file...

too many sites...


The app pool is essentially a collection of processes that manages the application threads. I'd suggest the way forward would be profile the applications' usage statistics and then determine the number that can be successfully managed in a single app pool. It depends completely upon function of the hardware and the your applications there really isn't a general number that makes sense in all cases.


I would start by creating some different scenarios. Create an app pool with just one site, then one with 5 sites, one with 10 sites, one with 50 sites.

Look at the resources that are used by each of these scenarios. Then you can come up with a number that works well with your application.

Also, it is worth looking into a web garden on your app pool. That way a single app pool can spread it's load across multiple processes.


First, I'd really be looking at adding servers not app pools here--that sounds a bit crowded.

As for the question at hand, if your deployment process is hands-off enough--which it should be with this number of apps--you can pretty much automate the creation of appropriate app pools, etc, too.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy