When to update production app to Rails 3.1?

I see that some people are updating their apps to Rails 3.1. When is the best time to update a production app? As soon as it is开发者_C百科 released? When the next stable version is released? A major release like Rails 4?

Currently running 3.07 app on Heroku.

Thanks.

EDIT: Yes, running Ruby 1.92p180.

Tests definitely.

The answer also depends on a lot of other factors about your setup such as:

• What is your current testing stratgey? Do you volume test?
• Do you have a lot of users that would drown your ability to respond if there's an issue?
• Do you have a failover / fallback strategy/plan if issues arise?
• What is your backup stratgey and how well do you execute it?
• How complex is your code and how much custom code is there?
• How similar are your development / test / production environments?
• Is there a particular business reason to upgrade now rather than wait a month or two (given that it was just released).
• Are you running ruby 1.9.2 (almost certainly but has to be checked).
• Have you planned for staff availability for the downtime/interruption "in case"
• Have you tested the actual planned move process on test servers to make sure there are no gotchas?

Generally I would wait 2-3 months. Especially so with Rails 3.1 as there were quite a few changes with this 'dot' release, although again tests should help - though that'll depend on their availability and completeness.

When all your tests pass.

I normally wait til at least the .1 release to update an existing production app. But i have apps runnig on 3.1 as they where developed using the betas and RCs, and so far no issues.

But seriously when all your tests pass.