# Heroku Investigates Puma Bug Causing High Response Times with Router 2.0

DevFeed: [Heroku Investigates Puma Bug Causing High Response Times with Router 2.0](<https://devfeed.tech/articles/pumas-routers-keepalives-oh-my-26489.md>)

Original publisher: [Read original article](<https://www.heroku.com/blog/pumas-routers-keepalives-ohmy/>)

Author: Elizabeth Cox

Published: 2024-11-21T18:13:05Z

Content type: article

Language: en

Sources: [Heroku](<https://devfeed.tech/sources/heroku.md>)

Topics: [Heroku](<https://devfeed.tech/topics/heroku.md>), [Ruby](<https://devfeed.tech/topics/ruby.md>), [Rails](<https://devfeed.tech/topics/rails.md>), [HTTP](<https://devfeed.tech/topics/http.md>), [servers](<https://devfeed.tech/topics/servers.md>)

Tags: [applications](<https://devfeed.tech/tags/applications.md>), [article](<https://devfeed.tech/tags/article.md>), [bug](<https://devfeed.tech/tags/bug.md>), [cloud-infrastructure](<https://devfeed.tech/tags/cloud-infrastructure.md>), [dashboards](<https://devfeed.tech/tags/dashboards.md>), [dynos](<https://devfeed.tech/tags/dynos.md>), [engineering](<https://devfeed.tech/tags/engineering.md>), [heroku](<https://devfeed.tech/tags/heroku.md>), [http](<https://devfeed.tech/tags/http.md>), [improvements](<https://devfeed.tech/tags/improvements.md>), [legacy](<https://devfeed.tech/tags/legacy.md>), [load](<https://devfeed.tech/tags/load.md>), [performance](<https://devfeed.tech/tags/performance.md>), [request](<https://devfeed.tech/tags/request.md>), [router](<https://devfeed.tech/tags/router.md>), [router-2-0](<https://devfeed.tech/tags/router-2-0.md>), [ruby](<https://devfeed.tech/tags/ruby.md>), [server](<https://devfeed.tech/tags/server.md>), [technical](<https://devfeed.tech/tags/technical.md>), [update](<https://devfeed.tech/tags/update.md>), [upgrade](<https://devfeed.tech/tags/upgrade.md>)

## AI overview

Heroku investigates a Puma bug that caused elevated response times for a small subset of applications after enabling Router 2.0. The article explains the investigation, reproduction conditions, mitigation guidance, and the subsequent Puma 7.0 fix.

## Source excerpt

Update: Puma 7.0 was released with a fix for the bug described in this article. We recommend Ruby applications upgrade to Puma 7.0.4 or higher. 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 [...] The post Pumas, Routers & Keepalives--Oh my! appeared first on Heroku.