This week, Heroku made Router 2.0 generally available, bringing features like HTTP/2, performance improvements and reliability enhancements out of the beta program!

Throughout the Router 2.0 beta, our engineering team has addressed several bugs, all fairly straight-forward with one exception involving Puma-based applications. A small subset of Puma applications would experience increased response times upon enabling the Router 2.0 flag, reflected in customers’ Heroku dashboards and router logs. After thorough router investigation and peeling back Puma’s server code, we realized what we had stumbled upon was not actually a Router 2.0 performance issue. The root cause was a bug in Puma!...

Last month, Heroku announced the beta release of Router 2.0, the new Common Runtime router!

As part of our commitment to infrastructure modernization, Heroku is making upgrades to the Common Runtime routing layer. The beta release of Router 2.0 is an important step along this journey. We’re excited to give you an inside look at all we’ve been doing to get here.

In both the Common Runtime and Private Spaces, the Heroku router is responsible for serving requests to customers’ web dynos. In 2024, Router 2.0 will replace the existing Common Runtime router. We’re being transparent about this project so that you, our customers, are motivated to try out Router 2.0 now, while it’s in beta. As...