Running 1.1 and 2.0 framework on same Windows 2003 box

[lleemon]

We have a Windows 2003 box with over 100 websites and various using the 1.1 framework. Can we install the 2.0 framework and run both 1.1 and 2.0 .net web apps?

[RobDog888]

All framework versions (1.0, 1.1, 2.0, 3.0, 3.5) can run side by side. For safty's sake you should test your apps under any proposed framework versioin change. For WinForm apps usually you target one framework version and the app will use that one but if its not designed for it then it may break if it is changed from an upgrade install of a new FW version. Now if you have multiple versions of th framework then it wil use what it was targeted for.

Here is an old chart on the different loading conditions for the first 3 framework versions.




With web apps its a be a bit different.

You can configure your site to use a particular framework version using IIS. Drawback is that only one specific version can be targetted and/or used per site. Separate sites can have different versions of the framework as their configured target. So no issues there.

So bottom line is yes but if you want to take advantage of the new FW version for a site, it must be individually configured to it.



Edit: WOOT! 40,000 POSTS!

[Edneeis]

With Windows 2003 and the web different versions of the framework can not run in the same process thus two different web applications using different frameworks can not be in the same application pool. If they are you may experience a 'server not available' error. Other than that it should be fine.

[RobDog888]

With IIS 5.0 you can run multiple versions of the framework with no changes or tweaks.

With IIS 6.0, yes there are issues with Application Pools. Multiple versions of the framework can run side by side but not in the same process. To work around this you can create a new application pool and move the site that you will be designating to use that framework into that pool.

[lleemon]

Thanks to all that replied. We tested this out and your suggestions worked great. We do have one other question. When setting up an additional website and change to 2.0 framework it restarts IIS shutting down all the sites. Does anyone see any issue with changing this setting so it doesn't restart? Or does it have to restart?

Thanks.

[RobDog888]

AFAIK, you need to restart IIS but at lest you dont have to reboot.

[Edneeis]

In IIS 5.0 you would have to set the site to use High Isolation mode if it used a different version of the framework.

We did not experience any restarting of the IIS when adding new websites. (Unless you meant the very first time after .NET 2.0 was installed).

[mendhak]

It's good practice to create a separate application pool for each of your websites.