Engineer for the future of Cloud
June 10-13, 2019
San Jose, CA

Fixing the performance of your (probably broken) HTTP/2 deployment

Patrick Meenan (Facebook)
1:30pm5:00pm Tuesday, June 11, 2019
Average rating: ****.
(4.00, 1 rating)



Prerequisite knowledge

  • A basic understanding of HTTP, transmission control protocol (TCP), and web serving (useful but not required)

What you'll learn

  • Learn how HTTP/2 is broken and how to fix it


Working HTTP/2 prioritization is critical for web performance. Even though most servers, content delivery networks (CDNs), and load balancers technically support HTTP/2 prioritization, it’s effectively broken and has no practical effect. When prioritization is broken, the impact on end-user performance can be dramatic and lead to tens of seconds of delays in rendering the critical content on the page.

Patrick Meenan shares some background on how he initially stumbled on the problem with Cloudflare’s HTTP/2 deployment, the root causes of the issue, and how Cloudflare fixed it. That was just the tip of the iceberg, though, and led to building a test suite that can test for working prioritization. Every deployment he tested was broken. You’ll use the test suite, find known issues, and learn resolutions for various platforms and how you can detect and resolve the issue with your own deployments. Finally, Patrick touches on the state of prioritization support in the browsers and upcoming changes with HTTP/3 and how that will impact the issue (or not).

Photo of Patrick Meenan

Patrick Meenan


Patrick Meenan is a software engineer at Facebook, where he’s helping make the web faster. Patrick has been working on web performance in one form or another for the last 25 years. Previously, he worked at Cloudflare and Google to make Chrome and the web faster. Patrick created the popular open source WebPageTest web performance measurement tool, runs the free instance of it at, and can frequently be found in the forums helping site owners understand and improve their website performance.