Introducing Rails Autoscale Free

Adam McCrea Twitter

June 9, 2021


Every app needs a safety net—something to catch you gracefully when traffic spikes or one of your servers has a problem.

Starting today, every Rails app on Heroku can have this safety net for FREE with the Rails Autoscale free plan.

The free plan includes:

  • Queue time monitoring for web requests and background jobs.
  • Autoscaling for web and worker dynos, up to 99 dynos.
  • Up to 20 autoscale events per month, with a 24-hour unlimited grace period.
  • Chat webhooks for autoscale notifications.
Rails Autoscale screenshot showing settings page

You can keep the free plan forever—there is no trial period. When you decide you need more than 20 autoscale events per month, you can upgrade to a paid plan based on how many dynos you need.

Q&A

What counts as an autoscale event?

An autoscale event is anytime Rails Autoscale automatically scales your app up or down. If you scale twice from 2–4 dynos then back down, that’s four autoscale events. Autoscaling will only be triggered after you’ve explicitly enabled it from your settings page.

Rails Autoscale screenshot showing queue time spike

What if I'm autoscaling by more than one dyno at a time?

Let's say you're using the advanced setting to scale by 2 dynos at a time. Autoscaling from 2–4 dynos in this scenario would count as a single autoscale event.

What happens when I exceed the 20 autoscale events?

We’ll send you an email to let you know you’ve used all of your autoscale events for the month. Your app will keep autoscaling for the next 24 hours as a grace period so you have time to upgrade.

After 24 hours, your app on the free plan will no longer autoscale until you upgrade your add-on plan or the month ends.

When does my autoscale event quota reset?

Your event quota will reset at the beginning of each calendar month. For example, if you use 20 autoscaling events on May 4th, autoscaling will be disabled on May 5th. Autoscaling will begin again on June 1st with 20 more autoscale events available.

How do I get started?

You can install Rails Autoscale via the Heroku CLI or from Heroku Elements. You’ll be guided through the process of installing the Rails Autoscale agent gem, and you'll be set!

Want to cut your Heroku bill in half
and never worry about your dynos again?
Learn more about Rails Autoscale