Installing .NET 4.0

Question

I'd like to install .NET 4.0 on my server but can afford to have any downtime on my current apps running in .NET 3.5 appPool. Will installing 4.0 cause any disruptions or breaks?

Answer 1

It's possible that installing .NET 4 will require a reboot, at least. I would imagine it would depend on what's already on the box. You should at least try it on a box which isn't critical (but is otherwise exactly the same as your production box) first.

Do you not have load-balancing which would let you install on one box at a time? If you're relying on a single server being up 24x7, you're already asking for trouble if there are problems of any kinds - as well as making it impossible to install any critical Windows Updates etc that might require a reboot.

Answer 2

It shouldn't. It usually doesn't require restart or anything.

Answer 3

It definitely does require a reboot some of the time, but not all of the time. There seems to be no information online about why, or if you can detect ahead of time if it will require a reboot or not. When we deployed it at work, it was about 60/40 requiring reboot or not, and there were no trends I could detect about OS or other variables influencing it in one direction or the other.

Answer 4

I wouldn't gamble on it. This is going to be very dependent on what patches are already installed on the server, what's running on it, etc. It's possible it won't require a restart, but in every scenario where I've installed it, I've hard to restart the server. Even if you keep patched well, plan on having to restart.