Ryan Underwood is a Staff SRE and tech lead on the Helix and Zookeeper SRE team at LinkedIn. Prior to LinkedIn, he was an SRE at Machine Zone and Google. Apart from his regular responsibilities, Ryan’s interest and expertise include debugging production kernel, I/O and containerization issues. His opinion about not treating software as a black box and his persistent approach to debugging complex problems are truly inspiring.

On several occasions, Ryan’s colleagues have leaned on him to solve an esoteric problem that everyone thought was insurmountable. Our main focus today is one such problem that Ryan and team ran into while upgrading machines to 4.x kernel that resulted in elevated 99th percentile latencies. We dive into what the problem was, how it was identified and how it was fixed. We discuss some of the tools and practices that are helpful in debugging system performance issues. And we also talk about Ryan’s background and how his curiosity landed him a career in Site Reliability Engineering. Please enjoy this deeply technical and highly educational conversation with Ryan Underwood.

Website link: https://softwaremisadventures.com/ryan

Music Credits: Vlad Gluschenko — Forest License: Creative Commons Attribution 3.0 Unported: https://creativecommons.org/licenses/by/3.0/deed.en

Ryan Underwood - On debugging the Linux kernel - #4