Dynos already run in different availability zones: https://devcenter.heroku.com/articles/production-check
You can take that a step further by running dynos in the European (eu-west-1) region: https://devcenter.heroku.com/articles/regions
You can take that a step further by running dynos in the European (eu-west-1) region: https://devcenter.heroku.com/articles/regions
It's not guaranteed. As I understand it, it's random.
And as for regions. They only help you locate content to a closer region. You cannot use them for balancing/redundancy. As any data or third party add-on you use, will manage it's data in it's own specific zone. Thus creating latency issues.
"Beta Testers,
Heroku Europe is ready to begin running your production apps!
Create an app in the region:
$ heroku create --region eu
As always, private betas should be considered confidential. Please don’t tweet, blog, or talk about this feature publicly until we announce it ourselves.
Documentation: https://devcenter.heroku.com/articles/regions Questions & feedback: eu-beta@heroku.com
Best,
The Heroku Team"