Tools for debugging, testing and using HTTP/2

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Cloudflare
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John Graham-Cumming
•9 min read•intermediate•
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•View Original
GolangHaskellHTTP/2HTTPSRuby

Overview

This article discusses various tools and techniques for debugging, testing, and utilizing HTTP/2, particularly in the context of CloudFlare's implementation. It covers browser extensions, command-line tools, online testing utilities, and libraries that facilitate working with HTTP/2.

What You'll Learn

1

How to use the HTTP/2 and SPDY Indicator extension in Google Chrome

2

How to install and use the is-http2-cli command-line tool

3

How to perform load testing using the h2load tool

4

How to debug HTTP/2 traffic using Wireshark

Key Questions Answered

What tools can I use to debug and test HTTP/2?
The article provides a variety of tools for debugging and testing HTTP/2, including browser extensions like HTTP/2 and SPDY Indicator, command-line tools such as is-http2-cli and curl, and online testing tools like KeyCDN's HTTP/2 test. These tools help developers verify HTTP/2 support and analyze performance.
How can I check if a website supports HTTP/2?
You can check if a website supports HTTP/2 using the is-http2-cli command-line tool or by using online tools like KeyCDN's HTTP/2 test. These tools will provide information on the supported protocols and help identify if HTTP/2 is enabled.
What is the purpose of the Claire extension?
The Claire extension for Google Chrome provides detailed information about how a web page was loaded, including whether it was served using HTTP/2, IPv6, or Railgun. This helps developers understand the performance and capabilities of their web applications.
How can I perform load testing for HTTP/2?
You can perform load testing for HTTP/2 using the h2load tool, which is part of the nghttp2 library. This tool allows you to simulate multiple requests and analyze the performance of your HTTP/2 server under load.

Technologies & Tools

Protocol
HTTP/2
The article discusses the implementation and tools related to HTTP/2 for improved web performance.
Library
Nghttp2
Provides tools like h2load for load testing and nghttp for command-line HTTP/2 requests.
Tool
Wireshark
Used for packet analysis and debugging of HTTP/2 traffic.

Key Actionable Insights

1
Utilize the HTTP/2 and SPDY Indicator extension to quickly verify the protocol being used on your web pages.
This tool provides immediate visual feedback on whether your site is using HTTP/2 or an older protocol, helping you ensure that your optimizations are effective.
2
Incorporate the is-http2-cli tool into your development workflow to regularly check HTTP/2 support for your applications.
Regular checks can help maintain compatibility and performance as you deploy updates or changes to your web services.
3
Use h2load for performance testing to understand how your server handles concurrent HTTP/2 requests.
This can help identify bottlenecks and improve server configurations to handle higher loads efficiently.

Common Pitfalls

1
Failing to verify HTTP/2 support can lead to performance issues if your application relies on its features.
Without proper testing, you may miss out on the benefits of HTTP/2, such as multiplexing and header compression, which can significantly enhance load times.
2
Neglecting to configure Wireshark properly for TLS decryption can hinder your ability to analyze HTTP/2 traffic.
Ensure you set the SSLKEYLOGFILE environment variable in Chrome to capture the necessary keys for decrypting traffic in Wireshark.

Related Concepts

HTTP/2 Performance Optimization Techniques
Understanding TLS And Its Impact On HTTP/2
Best Practices For Web Server Configuration