What is the best way to update an ASP.NET web application DLL?

Question

I have an ASP.NET web application which contains a DLL in the /bin folder 'Example.dll'. If I do not have any mention of 'Example.dll' in the Web.config, is it safe to simply replace it with a newer version of 'Example.dll', and the application will use it?

If not, what steps are needed?

Answer 1

Replacing the DLL will trigger the App Domain (the entire web application) to restart, any code using this DLL will use the new version upon restart. Current requests to the old one will complete, then shutdown.

So no additional steps are needed, just be aware the application will restart.

Answer 2

Yes, that's safe (assuming you've been careful and not made any breaking changes), but here's a tip I learned from bitter experience: don't backup the old version within the same folder. Even if you rename it something like Example.dll0, it may still confuse the framework.

Also, doing so will restart the app.