Staged rollouts

A staged rollout sends an update to only part of your users first. If something goes wrong, only that part is affected.

Publish to a percentage

npx tidepush publish --channel production --rollout 10 -m "New payment summary screen"

About 10% of devices get the update. The other 90% keep getting the update they had before.

Widen it

npx tidepush rollout <groupId> 50
npx tidepush rollout <groupId> 100

✔ Rollout set to 50% for android 4f2a…, ios 9b0e…

Or use the rollout control on the update in the dashboard.

How devices are chosen

Each device has a random client id that expo-updates creates on install. For each update, the server computes a number from 0 to 99:

bucket = SHA-256("<client id>:<update id>")  →  first 4 bytes  →  mod 100

The device is in the rollout if bucket < percentage.

 bucket:  0 ─────────── 9 ─────────────────────── 49 ───────────────────── 99
 10%  :   [  in  ]
 50%  :   [          in                          ]
 100% :   [                              in                                 ]

• A device's bucket for an update never changes. It won't flip back and forth.
• Raising the percentage only adds devices. Everyone who had it keeps it.
• Each update has its own buckets, so the same users aren't always first.
• Devices outside the rollout fall through to the newest older update they qualify for.
• Requests without a client id only get updates at 100%.

Lowering or pausing a rollout

You can set a lower percentage, including 0:

npx tidepush rollout <groupId> 0

New devices stop getting the update. But devices that already downloaded it keep it: they'd fall through to an older update, and expo-updates never moves to an older update. To actually take it away from them, roll it back.

A good routine

1. Publish to staging and test.
2. Promote to production at 5–10%: npx tidepush promote <id> --to production --rollout 10.
3. Wait a day. Watch your crash reporting and the dashboard's adoption numbers.
4. Go to 50%, then 100%.
5. If anything looks wrong, roll back.

Users only count once they relaunch

Remember a device needs two cold starts to run an update. Adoption after a few hours is mostly people who opened the app twice. The dashboard counts devices by the update they report running.

Partial rollouts and rollback

When you roll back, Tidepush republishes the most recent previous update that was at 100%. A previous update that was still partial is not a rollback target. Finish or roll back one rollout before starting the next.