Autoscale your Rack app the right way

Avoid downtime and reduce hosting costs.
We use request queue time to monitor your web servers and scale automatically.
$ bundle add judoscale-rack
You’ll be autoscaling in minutes

Why autoscale your Rack app?

Most web apps are over-provisioned. You’re paying through the nose for resources you don’t need, but you do it because you’ve been burned with downtime.

Even worse, you still encounter downtime and slow-downs! Traffic is variable and sometimes unpredictable, so even your extra servers aren’t always enough.

Autoscaling is the solution here, and it’s pretty simple. We monitor the capacity of your Rack app, and we scale your servers accordingly. You’ll never pay for resources you don’t need, and you’ll always have capacity to meet those sudden bursts of traffic.

Judoscale scaling charts

Explore for yourself in our sandbox app →

What makes Judoscale different?

While most autoscalers rely on generic metrics like CPU or total response time, Judoscale monitors the request queue time in your Rack app. Queue time is a way more reliable capacity metric that we’ve written about extensively, and we built our autoscaler with queue time in mind from the beginning.

We also give you a whole lot of control and visibility into your autoscaling that you won’t find elsewhere. Autoscaling is all we do, and we’ve been doing it for a long time.

  • Trusted by
    900+
    engineering teams
  • Over
    2.5 million
    autoscales per month
  • Since
    2017
    we are here to stay

The fastest autoscaler for Rack

With autoscaling decisions made every 10 seconds, Judoscale ensures your Rack app scales up quickly to meet demand.

screenshot of scaling up fast

Ready for Active Job

Whether you use Sidekiq, Solid Queue, or any other Active Job adapter, Judoscale can autoscale your workers to avoid bottlenecks.

screenshot of web and worker instances in Judoscale

Reduce Hosting Costs

Avoid overscaling with Judoscale’s precise autoscaling algorithm, saving you money on hosting costs without sacrificing performance.

screenshot of a Heroku bill

You’re In Control

Fine-tune your autoscale settings with Judoscale’s easy-to-use controls, ensuring the perfect configuration for your Rack apps.Explore the configs in our sandbox app

screenshot of Judoscale configuration options

Most applications have greatly overprovisioned resources, because resources are provisioned manually in response to developer stress (pages, calls, incidents) rather than automatically (in response to metrics, e.g. request queue time).

Nate Berkopec
The Complete Guide to Rails Performance

Judoscale’s deep integration with Sidekiq queues let us easily tag which queues we wanted a faster response. We were able to tune our scaling sensitivity for exactly our usage pattern of intermittent batches of large jobs.

Michael Buckbee
Founder, Gently Used Domains

If I was the king of the world, I would make it illegal to horizontally scale based on execution time. Scale based on queue depths, people!

Nate Berkopec
The Complete Guide to Rails Performance

I found Judoscale through Nate Berkopec’s Rails Performance workshop. Glad I did, because we’re very happy with Judoscale!

Eric Kurzenberger
Director of Engineering, Mitchell Stores

Chameleon has been extremely stable thanks to Judoscale. We have very high spikes in traffic, and I don’t even have to think about it.

Brian Norton
Co-founder & CTO, Chameleon

We could see the care in Judoscale’s documentation, the gems were well-documented and designed with a general sense of quality.

Sean Devine
CEO, XBE

We’re really impressed by the simplicity and ease of use of Judoscale. We’ve gone from constant worries over site performance, to complete confidence in our configuration. What a great tool!

Christopher Batts
Co-Founder & CEO, Setyl

Start autoscaling for free

Setup takes less than 5 minutes