By default ,Fly created two machine for high availability . If you want to deploy only a single machine ,use the following flag .
fly deploy --ha=false
It’s maybe because of RootFS fees .Fly charge for stop machines RootFS usage. According to fly, you can stop this charge by running your machine 24/7. To disable auto stopping your machine, please made following change to your fly.toml file
auto_stop_machines = false
App builder are free machines which are created for deploy your apps to fly platform. App Builders are required for every single build.So if you delete all the app builders and initiate a new build/deploy for your app, a new app builder machine will be created .That is the reason they are keeps coming back.
They are completely Free. You don’t need to worry about them , They will automatically delete after a specific time and not added to your bill.
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