1.
http://www.flickr.com/photos/nzbuu/4093456029Are Today’s Good Practices…Tomorrow’s Performance Anti-Patterns?@andydavies#WebPerfDays, AmsterdamSaturday, 18 May 13

2.
People like recipeshttp://www.flickr.com/photos/sowrey/2441134911Saturday, 18 May 13

3.
Browsers already use the network differentlySaturday, 18 May 13

4.
Saturday, 18 May 13

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New network protocols are coming herehttp://www.flickr.com/photos/jonlachance/3427660741Saturday, 18 May 13

6.
HTTP 1.1SPDYSPDY testing stops tracking at onload - some requests missing after onloadDifferences in TCP Connection UseSaturday, 18 May 13

7.
Test EnvironmentImage Credit-Amazon EC2 - Small Instance - Dublin-Apache 2.2- GZIP- Keep-Alive- mod_pagespeed- mod_spdy-‘Off the shelf’ web site template-WepPageTest, Dulles / Chrome / CableSaturday, 18 May 13

8.
Minimal Optimisations - HTTP 1.1 vs SPDY(GZIP / Keep-Alive / initcwnd 10)Saturday, 18 May 13

9.
Minimal Optimisations - HTTP 1.1 vs SPDYSPDY is faster(GZIP / Keep-Alive / initcwnd 10)Saturday, 18 May 13

10.
Waterfall for HTTP TestSaturday, 18 May 13

11.
Waterfall for SPDY TestRemember requests after onload not tracked in testSaturday, 18 May 13

12.
So which rules are most likely to be at risk?- Split dominant content domains- Reduce requests- Merging- Sprites- DataURIsSaturday, 18 May 13

13.
Sharding CSS background: url() imagesSaturday, 18 May 13

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Sharding CSS background: url() imagesSharded page is much slowerSaturday, 18 May 13

15.
Connection to shard opened laterNew TCP connectionopenedSaturday, 18 May 13

16.
Sharding <img src=Saturday, 18 May 13

17.
Sharding <img src=Sharded page is marginally (0.5s) faster!Saturday, 18 May 13

18.
Other tests carried out- Sharding JS- Merging CSS- Merging JS- Server Push(Fonts, third-party JS not yet tested)Saturday, 18 May 13

19.
What about the traditional CDN?http://www.flickr.com/photos/jvk/166337955Saturday, 18 May 13

20.
How much do we rely on inline JavaScript?http://www.flickr.com/photos/jfraissi/6352877711Saturday, 18 May 13

21.
Content-Security-Policy“Content Security Policy, a mechanismweb applications can use to mitigate abroad class of content injectionvulnerabilities, such as cross-sitescripting (XSS)”http://www.w3.org/TR/CSP/Saturday, 18 May 13

22.
ExampleContent-Security-Policy: script-src http://www.site.comCan re-enable inline scripts, but increases XSS riskContent-Security-Policy script-src selfOnly allow scripts to be executed if they come from adesignated host, disables inline scripts by default.Saturday, 18 May 13

23.
Typical async script loader<script type="text/javascript">function() {var js = document.createElement(script);js.async = true;js.src = myscript.js;var e = document.getElementsByTagName(script)[0];e.parentNode.insertBefore(js, first);})();</script>Relies on inline JSSaturday, 18 May 13

24.
69% of visitors support async attribute<script async src="myscript.js"><script>http://caniuse.com/script-asyncWhat other techniques rely on inline JS?Saturday, 18 May 13

25.
“Situational Performance Optimization,The Next Frontier”http://calendar.perfplanet.com/2012/situational-performance-optimization-the-next-frontier/Guy PodjarnySaturday, 18 May 13

26.
# Disable concatenation for SPDY/HTTP 2.0 clients<ModPagespeedIf spdy>ModPagespeedDisableFilters combine_css,combine_javascript</ModPagespeedIf># Shard assets for HTTP 1.x clients only<ModPagespeedIf !spdy>ModPagespeedShardDomain www.site.com s1.site.com,s2.site.com</ModPagespeedIf>mod_pagespeed & mod_spdy = tools to experimentHigh Performance Browser Networking, Ilya GrigorikSaturday, 18 May 13

27.
http://www.flickr.com/photos/simeon_barkas/2557059247The end for hand crafted optimisations?Saturday, 18 May 13

28.
Limits to what protocols or automation can fixRequests by Domain Bytes by DomainSaturday, 18 May 13

29.
- Some good practices will become obselete-Testing tools have a few issues- Browsers may need better loading hints- Start experimenting nowSaturday, 18 May 13

30.
Thank You!@andydavieshello@andydavies.mehttp://slideshare.net/andydavieshttp://www.flickr.com/photos/nzbuu/4093456029Saturday, 18 May 13