Sleep and wake

What you get

• Idle apps stopped, using no memory or processor
• Woken by the next request
• A short starting page for people waiting
• Scheduled jobs wake the app and let it sleep again
• Cached pages answered while the app sleeps
• Health monitors do not keep an app awake

How it works

When nobody has used an app for a while, Whisk stops its container. The plan sets how long that wait is. The data stays in the database and file storage, so nothing is lost.

The next request wakes the app. Caddy, the open-source web server in front of every app, holds the request while the app starts and then passes it on. If starting takes more than two seconds, a person in a browser sees a short starting page that opens the app when it is ready.

Scheduled jobs wake the app for their run, and it goes back to sleep shortly after the last step. Pages the app marks as cacheable are answered from the edge cache without waking it. An app that must answer at once can be always on.

Example

An electrical contractor has an app for recording test certificates that electricians use a few times a week. It sleeps between uses, and the first person to open it waits a few seconds while it starts. The rest of the day it answers straight away.

For your coding agent

health: { path: /health, timeout: 90 }
always_on: false

Keep start-up short: under five seconds from process start to a healthy answer is the target in the app rules. Every field is in the whisk.yaml reference.