Rollbacks
Put an earlier production deployment back in front of your users.
Because deployments don't change after they're created, going back means pointing traffic at an older one. Nothing is rebuilt.
Roll back
- Open the app's deployment list.
- Open the menu of the deployment you want back and select Rollback.
- Check the current and target deployments in the dialog and confirm.
Production URLs and custom domains switch to the target right away. If the target is still running, the switch takes seconds. The deployment that was replaced last stays up for 30 minutes for exactly this. An older, stopped deployment has to start its instances first.
While you're rolled back
After a rollback, production stays on the version you picked. New pushes to the default branch still build and deploy, but they don't take over production traffic. Otherwise the next push would undo the rollback you just made.
The app's overview shows that it's rolled back.
Go back to normal
Select Promote on the deployment that should serve production. Teral moves traffic to it, and later pushes take over production again as usual.
Promote also works without a rollback, to put any earlier production deployment live on purpose.
Roll back or fix forward?
Roll back when users are affected and you need the old version now. Push a fix when it's small and you're confident in it. A rollback is faster because it reuses a build you already have.