What level of concern should I attach to deploying the .NET framework 3.5 onto a production application server currently hosting about 20 .NET framework 2.0 applicatons?
I have a run into resistance to my request to rollout the .NET framework 3.5 into our environment. We do not have the ability to regression test with confidence nor do we have available resources to test each application with confidence.
It is my understanding that the .NET framework X.X is, as a primary design objective, constructed and proven to allow 1.0, 1.2, 2, 3, 3.5 etc.. to be deployed on the same machine with with high confidence that the interplay between the versions will not break eairlier version.
I have tried to find 'breaking changes' that are reported in the IT community and thus far have found very very few examples and as such I am inclined to press for the rollout of this runtime with minimal testing.
What is your preceived level of concern about this approach to rolling out .NET 3.5 in this situation.
Best Answer
My level of concern is very low. The only way in which the 3.5 framework will interact with existing 2.0 applications is due to the service pack applied to the 2.0 CLR during the 3.5 install. Namely service pack1. So after the install all of your previous apps will start running on CLR 2.0SP1 vs. CLR 2.0.
So really this is a question of how much confidence do you have in the service pack?
Here is a link to the service pack and the list of bugs they fixed. All bug fixes are in a way a breaking change and can affect application behavior (otherwise why fix it?).