Judoscale is an evolution of Rails Autoscale. While Rails Autoscale is the best autoscaler for Rails apps, Judoscale will be the best autoscaler for every Heroku app.

Judoscale will keep everything that makes Rails Autoscale great, plus…

  • Autoscaling for Heroku apps written in any language or framework.
  • Autoscaling triggered by Heroku memory & timeout errors.
  • Beautiful, live-updating metrics.
  • Faster autoscaling than ever.
  • A public API.
  • Pre-scaling for expected traffic spikes.
  • Bad dyno detection with automatic restarts.
  • Extensibility via Zapier.

What does this mean for Rails Autoscale?

While Judoscale is in beta, Rails Autoscale is still the preferred autoscaler for Rails apps. Since Judoscale is built upon the Rails Autoscale codebase, we’ll be integrating as many Judoscale goodies into Rails Autoscale as we can.

When Judoscale has reached feature parity with Rails Autoscale and is out of beta, we will remove Rails Autoscale from the Heroku marketplace. We will continue to support Rails Autoscale customers forever. Since the two apps share the same codebase, Rails Autoscale will not get “stale”.

Many Rails Autoscale customers will want to migrate to Judoscale. There are some features that can only be offered in Judoscale (see “How is Judoscale different” below). We’re not there yet, but when the time comes it’ll be a smooth, optional migration process.

Why build a brand new add-on?

Unfortunately there’s no way to rename a Heroku add-on, and “Rails Autoscale” doesn’t work well for a framework-agnostic tool.

How is Judoscale different?

Judoscale adds a log drain endpoint for your Heroku apps, so we’re able to measure things like response time and throughput without a language-specific adapter. This also enables autoscaling based on Heroku errors or memory consumption—things an adapter library would never see.

Adapter libraries will still be available for the most popular languages in order to measure request queue time on web dynos and job queue time on worker dynos. (This is how Rails Autoscale currently works with the rails_autoscale_agent gem.)

What’s the status?

Judoscale is currently in beta, which means the only available plan is “Early Access”, which is free. Early access users will also get two months free after the beta period ends.

Autoscaling web dynos based on response time is complete. We’re currently focused on building adapter libraries that add support for request queue time and worker autoscaling, and building out a proper Judoscale site with documentation.

Getting help

As mentioned above, the Judoscale documentation site isn’t ready yet. Until then, please refer to the Judoscale docs in the Heroku dev center.

If you have any questions that aren’t answered there, please email us.