# Upgrade to Puma 7 to Fix Keep-Alive Request Fairness in Ruby Apps

DevFeed: [Upgrade to Puma 7 to Fix Keep-Alive Request Fairness in Ruby Apps](<https://devfeed.tech/articles/upgrade-to-puma-7-and-unlock-the-power-of-fair-scheduled-keep-alive-26505.md>)

Original publisher: [Read original article](<https://www.heroku.com/blog/upgrade-to-puma-7-and-unlock-the-power-of-fair-scheduled-keep-alive/>)

Author: Richard Schneeman

Published: 2025-11-05T21:42:16Z

Content type: article

Language: en

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

Topics: [upgrade](<https://devfeed.tech/topics/upgrade.md>), [Ruby](<https://devfeed.tech/topics/ruby.md>), [Heroku](<https://devfeed.tech/topics/heroku.md>), [Latency](<https://devfeed.tech/topics/latency.md>), [servers](<https://devfeed.tech/topics/servers.md>), [Low Latency](<https://devfeed.tech/topics/low-latency.md>)

Tags: [engineering](<https://devfeed.tech/tags/engineering.md>), [heroku](<https://devfeed.tech/tags/heroku.md>), [latency](<https://devfeed.tech/tags/latency.md>), [performance-optimization](<https://devfeed.tech/tags/performance-optimization.md>), [ruby](<https://devfeed.tech/tags/ruby.md>), [servers](<https://devfeed.tech/tags/servers.md>), [upgrade](<https://devfeed.tech/tags/upgrade.md>), [web](<https://devfeed.tech/tags/web.md>)

## AI overview

The article explains a keep-alive scheduling bug in Puma 6 and earlier that could let one connection monopolize a thread and delay queued requests. Puma 7 introduces proportional sleeping to balance connections across workers, and Puma 7.1.0 restores the fast-inline optimization with fairness safeguards. It also describes the upgrade and verification commands.

## Source excerpt

Puma 7 is here, and that means your Ruby app is now keep-alive ready. This bug, which existed in Puma for years, caused one out of every 10 requests to take 10x longer by unfairly "cutting in line." In this post, I'll cover how web servers work, what caused this bad behavior in Puma, and [...] The post Upgrade to Puma 7 and Unlock the Power of Fair Scheduled Keep-alive appeared first on Heroku.