Regions

Watasu runs apps in one region today, and supports multiple zones for add-on followers.

App regions

Apps deploy to eu today. That’s currently the only app region — when you create an app, it goes there regardless of the --region flag.

watasu create my-app --region eu

The --region flag exists for forward-compatibility. As more app regions become available, the same flag will let you pick.

Add-on follower regions

PostgreSQL followers (read replicas) can be placed in specific zones for latency or geographic distribution:

Zone	Notes
nbg1	Nuremberg
fsn1	Falkenstein
hel1	Helsinki

Use --region when creating a follower:

watasu pg:follow DATABASE_URL --app my-app --name reporting-db --plan standard-1 --region hel1

This is a different concept from the app’s region — the follower lives in the chosen zone, while the primary database stays where the app is.

Picking a region

For the app: there’s currently nothing to pick. You go to eu.

For followers: pick the zone closest to whatever’s reading from them most often. Most teams pick the zone closest to their primary, which keeps replication latency low.