How will .NET 3.5 SP1 impact my .NET 1.1 applications?

Question

If I have a number of existing applications written and deployed w/ .NET 1.1, is there any risk to installing .NET 3.5 SP1 on the servers? My understanding is that .NET 3.5 SP1 only works with the .NET 2.0 codebase, so it will not touch or affect my .NET 1.1 applications.

Can you also point me to any pertinent MSDN documentation? I've searched but can't find anything.

Thanks!

Answer 1

3.5SP1 won't have any real effect if your code already works side-by-side with 2.0; the important factor is the choice of CLR: if it already gets this right, then you shouldn't be hugely affected. In this case, even if the 2.0 CLR is chosen (1.1 code can run in 2.0), you will only see changes from the 2.0 service packs that are bundled in 3.5SP1. This might have some subtle impacts on ThreadPool usage etc, but they should be minimal.

Of course, if your 1.1 code isn't already 2.0-safe, then there are a lot more changes to watch out for - things like thread exceptions always being fatal... you would want to actively request 1.1.

Answer 2

It's not clear where the applications are running or what they are.

• If they're ASP.NET, then you can tell IIS which version of the framework to use
• If they're WinForms applications running on a client, it may depend on how they talk to the server
• If thye're other applications on the server, you can tell .NET which version to use

Sorry to be vague - if you can give more information we may be able to help you more.

Answer 3

If you have both .NET 1.1 and .NET 2.0, your 1.1 applications will use the 1.1 runtime.

If you only have .NET 3.5, your 1.1 applications will use the 2.0 runtime.

If you both .NET 1.1 and .NET 2.0 and have both 1.1 and 2.0 applications, no problem. Each program gets its own instance of the correct runtime.

If you both .NET 1.1 and .NET 2.0 and have a program that has both 1.1 and 2.0 plugins, you are screwed. There is a 50-50 chance the program will load the 1.1 runtime first, causing the 2.0 plugin to fail. (Only one runtime is allowed per application.)

Answer 4

I have .NET 3.5 SP1 installed on a server with some existing .NET 1.1 applications and haven't noticed any problems whatsoever. The framework versions are completely distinct with respect to 1.1 and 3.5, though I understand that 3.5 includes some patches to 2.0 that might change behavior for 2.0 apps. I haven't noticed anything there either.

You might be interested in this blog post that covers a lot of ground with regards to updating, but specifically mentions that leaving 1.1 apps alone is ok. It also has a lot of references to other sources.