Web Compatibility and Performance Testing in a Multi-Browser World

Web Compatibility and Performance Testing in a Multi-Browser World
Imad Mouline, CTO, Gomez
(@imadmouline)
Buddy Brewer, Director of Engineering, Agent Technology, Gomez (@bbrewer)

Agenda
The problem and the upside
Functional validation across browsers
Performance optimization across browsers
Raw vs. perceived performance
Key takeaways and Q&A

The Problem
Building applications is more complex
Developers now support an interrelated mess of technologies that differ from browser to browser
Networking stack
JS engine
Rendering technologies (CSS, Canvas, SVG)

The Upside
Browsers provide better performance, richer functionality
The rate of change is accelerating, with competition between vendors leading to massive gains in performance

How?
We need to understand how our applications perform in real browsers on the real network
We need to know both what users encounter and what they perceive

Asymmetric Advantages of Modern Browsers
Dramatically faster JS engines
Greater connection parallelism
Client side storage
Native CSS selectors
2D compositing (Canvas, SVG)

Testing Presentation
Bespin determines browser Canvas support at runtime
Which browsers provide adequate support?

Yes: Firefox 3.5, Safari 4

No: Firefox 2, Safari 3, Any IE

Maybe: Chrome

Functional Validation
As new versions ship, do the expected browsers still work?
As new browsers are released, do our applications still work?

Revisiting Performance Optimization
Are our old techniques still relevant as the browsers we target evolve?
Example: Domain sharding
Legacy browsers allow 2 connections per hostname
Domain sharding increases parallelism to boost static object performance via pointing multiple hostnames to the same host

Optimizing IE6 Behavior
For older browsers, this could represent an easy 50% load time savings

Optimizing IE6 Behavior
What’s the catch?

De-optimizing IE8 Behavior
In IE8 (and Firefox and Safari and Chrome) using domain sharding leads to a glut of simultaneous connection creation and a dramatic performance hit

Lessons
Optimization techniques must evolve along with the browsers
So, performance testing should take into account browser differences
And to do that, we need to know what browsers are visiting our site

Performance Differences by Browser
Difference between quickest and slowest browser load time equals 13.226 seconds
Large sample of US end-users, on broadband connections, visiting a particular page on a web site over a 48 hour period

Load Time vs. Perceived Render Time
Load time for MS Internet Explorer higher than Firefox
Perceived render time for MS Internet Explorer lower than Firefox
Perceived render time is the amount of time needed for the page layout to stabilize and for all content visible to the end-user above the fold to be completely rendered

Optimizing Perceived Render Time & User Experience
Most prominent image on site loads almost last
Changing load order will not impact raw page performance, but will improve perceived render time and user experience

What is the download order?

Factors that impact object download order
Browser type / version
Host latency, concurrency differences
Geography
Geography???

San Jose

Boston

Browser Cache Impact
Cache Level
Page Load Time

Takeaways – Summary
Know your end-users
Identify where and how they use your application, how they connect to the network, when they do it, where they do it from, what browser they use, etc…
Deliver on their expectations
Know your entire application
Build performance into your process
Improve raw, workflow, and perceived performance
Continuously evaluate your performance targets
Measure what matters
Measure from your end-users’ perspective
Align your end-users’ web experience with your requirements and ultimate business goals

Please complete an evaluation.

Questions?

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Web Compatibility and Performance Testing in a Multi-Browser World

by Compuware APM on Sep 21, 2009

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Web Compatibility and Performance Testing in a Multi-Browser World — Presentation Transcript