Introduction:

We’re excited to announce public beta support for HTTP/2 on both Heroku Common Runtime and Private Spaces. HTTP/2 support is one of the most requested and desired improvements for the Heroku platform. HTTP/2 is significantly faster than HTTP 1.1 by introducing features like multiplexing and header compression to reduce latency and therefore improve the end-user experience of Heroku apps.

Since 2023, we’ve been working on a large platform modernization of our Common Runtime router. This project will allow us to start delivering more modern networking for Heroku. With the majority of that work now complete, we’re excited to focus more on the future and new features.

What...

This article was originally authored by Srinath Ananthakrishnan, an engineer on the Heroku Runtime Networking Team

Summary

This following story outlines a recent issue we saw with migrating one of our internal systems over to a new EC2 substrate and in the process breaking one of our customer’s use cases. We also outline how we went about discovering the root of the issue, how we fixed it, and how we enjoyed solving a complex problem that helped keep the Heroku customer experience as simple and straightforward as possible!

History

Heroku has been leveraging AWS and EC2 since the very early days. All these years, the Common Runtime has been running on EC2 Classic and while there have...

Since April 2021, the Heroku Runtime team has been working to deploy upgrades to the infrastructure powering Common Runtime apps, and we’re excited to formally announce the performance improvements that customers are already seeing.

When this Changelog post was published in May introducing the changes, almost all Common Runtime apps had been migrated from what we internally called the “classic“ infrastructure to the new “sharded” architecture. In addition to performance enhancements, this migration is expected to result in lower latency across the platform.

Around 99.9% of customers didn’t have to make any changes to their Heroku apps to benefit from these upgrades, and dyno prices are...