stevesouders.com/docs/ny-meetup pptx Disclaimer: This content does not necessarily reflect the opinions of my employer.

backendfrontend “waterfall chart”

Top 10 24% - backend 76% - frontend

10,000+ 8% - backend 92% - frontend

blog.catchpoint.com/2012/06/01/facebook-outage-wake-up-call-for-websites/

www2012.wwwconference.org/proceedings/proceedings/p41.pdf

research.att.com/articles/featured_stories/2011_03/201102_Energy_efficient

Mobile State Machine ?

, requests kB seconds start render seconds PLT mbox.js docwrites /mbox/standard blocks ie7.css blocks rendering don’t docwrite scripts domain sharding PNGs take 3-6 seconds to download

quickbooks.intuit.com requests kB seconds start render seconds PLT mbox.js docwrites /mbox/standard blocks ie7.css blocks rendering don’t docwrite scripts domain sharding add caching headers

turbotax.intuit.com requests kB seconds start render seconds PLT rendering extremely blocked concat scripts, concat stylesheets don’t mix inline & external scripts don’t docwrite scripts domain sharding add caching headers sprites

turbotax.intuit.com this is turbotax this is turbotax on Page Speed

HTTP Archive: 54K URLs, 4.6M resources 55% - NO caching headers 18% - cacheable < 1 day } 73%

adoption is slow

Why so few caching headers? resources are dynamic lack of awareness

“uncacheable” resources aren’t very dynamic 2 weeks is a long gap - daily would be higher 46% 38% Jan 15 46% Feb 1Feb 15 55% uncacheable same as Jan 15

44% 35% “uncacheable” resources are LESS dynamic 2 weeks: 46% (uncacheable) vs. 44% (all) 4 weeks: 38% (uncacheable) vs. 35% (all) who votes for “lack of awareness”? Jan 15 46% Feb 1Feb 15 same as Jan 15 all resources

36% of resources unchanged after 1 month only 11% of resources cacheable for > 1 month

“uncacheable” resources are LESS dynamic! who votes for “lack of awareness”? 44% vs. 46% 35% vs. 38%

% of users missing cacheable resources 20% of page views

* Based on available disk space – I had 50 GB free. (my) browser cache sizes: Chrome: 320 MB (cap)* IE 9: 250 MB IE 7-8: 50 MB Firefox 11: 830 MB* Opera 11: 20 MB iPhone 4: MB Galaxy Nexus: 18 MB

Chrome for Windows stats: 30% (48%?) of users have a full cache full cache users reach that point after 4 hours of active browsing (20 clock hours) 7% of users clear their cache 1+ per week 19% of users experience “fatal cache corruption” 1+ per week

recap: resource owners underutilize max-age users are often missing cacheable resources cache sizes are small; caches fill quickly

what can we do? gather more/better stats make caches bigger (and fix corruption) improve purging logic (mime type, etc.) more intelligent, personalized browsers

cache compressed or uncompressed? Browser Compressed responses cached compressed? Chrome 17yes Firefox 11yes IE 8no IE 9no Safari 5no Opera 11yes