Kernel Version Upgrade in Progress

Change effective on 03 November 2023

Heroku is upgrading the Linux kernel powering dynos on both Common Runtime and Private Spaces. This is a non-breaking change and no customer action is required to receive the upgrade.

The updated kernel has new features and system calls such as io_uring and epoll_pwait2 that may unlock performance improvements for some apps. See the roadmap for more discussion.

Once all Heroku apps are upgraded an additional changelog entry will be published and this changelog entry will be updated.