THIRD PARTY PERFORMANCE

Guy Podjarny (@guypod)
CTO, Web Experience, Akamai

Faster ForwardTM

©2013 Akamai
What’s a third party?

- Not a 1st Party?
- Infrastructure & code managed by someone else
- What’s not a 3rd party:
-

Reused Software (e.g. jQuery, Apache) – premium or free
Commercial Hardware (e.g. ADC, WAF)
Cloud Provider (e.g. AWS)
CDN (e.g. Akamai)

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©2013 Akamai
Where are the third parties?

- A tag on the page
- Analytics/trackers - invisible
- Image Tags & Scripts
- Non-critical page components (e.g. Share buttons, Get feedback…)
- Critical Page Components (A/B Testing, Shopping Cart
Personalization, Ads(?)..)

- An inline Cloud proxy (e.g. MotionPoint, SiteSpect)

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©2013 Akamai
# Domains Per Page

Sep 2013 Percentiles:
- 25th : 4 domains
- 50th : 10 domains
- 75th : 21 domains
- 90th : 36 domains

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©2013 Akamai
Ghostery Data - Media

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Ghostery Data - Retail

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3rd Party Extravaganza!

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©2013 Akamai
Airbnb Home Page

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©2013 Akamai
Airbnb Location Page

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©2013 Akamai
Why Should you Care? (from a performance perspective)

- Single Point of Failure – SPOF
- Scripts block rendering of everything below them

- Delayed load event
- Users see progress indicators for longer
- Other deferred actions get delayed - e.g. $.ready(myfunc)

- Delayed 1st party scripts
- Resource Contention
- Battery Consumption (on mobile)

Faster ForwardTM

©2013 Akamai
SPOF
Home Page, Optimizely & Truste Down

Business Week, Truste Down

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22 Secs

45 Secs

22 Secs

©2013 Akamai
SPOF – Not Only Your Homepage

Category Page, BazaarVoice down

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23 Secs

©2013 Akamai
Airbnb.ca homepage: SPOF delays late actions

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©2013 Akamai
New York Page

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©2013 Akamai
New York Page SPOF

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©2013 Akamai
The 1st Party Arsenal

- Async
- Delay onload (async att) vs don’t delay onload (IFrame)

- Defer Execution
- Defer Download
- Remove Tag

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©2013 Akamai
Analytics & Beacons

- Goal: Async without delaying onload
- Shouldn’t delay visible content
- Defer not great since it’s likely to miss users

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©2013 Akamai
Beacons that don’t delay onload

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©2013 Akamai
Beacons that don’t delay onload

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©2013 Akamai
Q: Do Script-Inserted Beacon Images Delay Onload?
http://stevesouders.com/cuzillion/?c0=bi1dfff2_0_f

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©2013 Akamai
Yes – Beacons delay onload (on most browsers)
http://www.browserstack.com/screenshots/3c4be740eee4ad95af43ef0fc6a800d7a7aa7758

Beacons didn’t
block onload on:
- IE 7
- IE 8

Faster ForwardTM

©2013 Akamai
Works for Images Too!

Faster ForwardTM

©2013 Akamai
Analytics & Beacons

- Goal: Async without delaying onload
- Shouldn’t delay visible content
- Defer not great since it’s likely to miss users

- Technique: Dynamically generated IFrame
- Only works if no page manipulation is required

- Catches and what can you do about them
- Inline & external script relationships
- Event registration

Faster ForwardTM

©2013 Akamai
External Script

Cringe…

Dependent Inline Script
Further Dependent
External Script

Further down
dependent
inline script
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©2013 Akamai
Run “inline” script at onload

Slight Snag…
But you catch my drift…
Don’t forget this one!
(combine all dependents to
avoid race condition bugs)

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©2013 Akamai
FYI: Omniture Workarounds

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©2013 Akamai
Beacon API – Draft W3C Spec

Faster ForwardTM

©2013 Akamai
Non-Critical Page Components

- Goal: Defer Download
- If they’re not critical, they shouldn’t content with the rest

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©2013 Akamai
Defer Download Example

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©2013 Akamai
Defer Download Example

Faster ForwardTM

©2013 Akamai
Non-Critical Page Components

- Goal: Defer Download
- If they’re not critical, they shouldn’t content with the rest

- Catches and what can you do about them
-

Event registration
Inline & external script relationships
document.write()
Execution order

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©2013 Akamai
Nullify document.write()

- Built into browsers (at least IE 9+, Safari, Chrome & Firefox)
- Firefox even gives a nice console error…

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©2013 Akamai
Resource Priorities

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©2013 Akamai
Critical Page Components

- Methodology: Async with blocking onload
- Keep 3rd parties from blocking 1st party content
- Delay onload as page not complete until component is loaded

Faster ForwardTM

©2013 Akamai
Async with blocking onload

Faster ForwardTM

©2013 Akamai
Critical Page Components

- Methodology: Async with blocking onload
- Keep 3rd parties from blocking 1st party content
- Delay onload as page not complete until component is loaded

- Catches and what can you do about them
-

Event registration
Inline & external script relationships
document.write()
Execution order

Faster ForwardTM

©2013 Akamai
Async scripts with Execution Order

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©2013 Akamai
Interim Summary

- Analytics/Beacons – Async without delaying onload
- Non-Critical Widgets – Defer Download (and Execution)
- Critical Widgets – Async with delaying onload

Faster ForwardTM

©2013 Akamai
Resource Timing Opt-In

Ask Require All your 3rd Party Vendors to add this header!
-

Unless they give you a REALLY good privacy reason not to.

Faster ForwardTM

©2013 Akamai
3rd Party Checklist – Work in Progress…

@bentlegen

@igrigorik

@bbinto

@guypod
Faster ForwardTM

@triblondon

Kyle Kinnaman
©2013 Akamai
Summary

- 3rd Party tags are a part of our reality…
- Pick your strategies:
- Analytics/Beacons – Async without delaying onload
- Non-Critical Widgets – Defer Download (and Execution)
- Critical Widgets – Async with delaying onload

- Track the Beacon & Resource Priorities Specs
- Challenge your 3rd party vendors on their perf & availability

Faster ForwardTM

©2013 Akamai
Questions?
THIRD PARTY PERFORMANCE

Guy Podjarny (@guypod)
CTO, Web Experience, Akamai

Faster ForwardTM

©2013 Akamai

Third party-performance (Airbnb Nerds, Nov 2013)

  • 1.
    THIRD PARTY PERFORMANCE GuyPodjarny (@guypod) CTO, Web Experience, Akamai Faster ForwardTM ©2013 Akamai
  • 2.
    What’s a thirdparty? - Not a 1st Party? - Infrastructure & code managed by someone else - What’s not a 3rd party: - Reused Software (e.g. jQuery, Apache) – premium or free Commercial Hardware (e.g. ADC, WAF) Cloud Provider (e.g. AWS) CDN (e.g. Akamai) Faster ForwardTM ©2013 Akamai
  • 3.
    Where are thethird parties? - A tag on the page - Analytics/trackers - invisible - Image Tags & Scripts - Non-critical page components (e.g. Share buttons, Get feedback…) - Critical Page Components (A/B Testing, Shopping Cart Personalization, Ads(?)..) - An inline Cloud proxy (e.g. MotionPoint, SiteSpect) Faster ForwardTM ©2013 Akamai
  • 4.
    # Domains PerPage Sep 2013 Percentiles: - 25th : 4 domains - 50th : 10 domains - 75th : 21 domains - 90th : 36 domains Faster ForwardTM ©2013 Akamai
  • 5.
    Ghostery Data -Media Faster ForwardTM ©2013 Akamai
  • 6.
    Ghostery Data -Retail Faster ForwardTM ©2013 Akamai
  • 7.
    3rd Party Extravaganza! FasterForwardTM ©2013 Akamai
  • 8.
    Airbnb Home Page FasterForwardTM ©2013 Akamai
  • 9.
    Airbnb Location Page FasterForwardTM ©2013 Akamai
  • 10.
    Why Should youCare? (from a performance perspective) - Single Point of Failure – SPOF - Scripts block rendering of everything below them - Delayed load event - Users see progress indicators for longer - Other deferred actions get delayed - e.g. $.ready(myfunc) - Delayed 1st party scripts - Resource Contention - Battery Consumption (on mobile) Faster ForwardTM ©2013 Akamai
  • 11.
    SPOF Home Page, Optimizely& Truste Down Business Week, Truste Down Faster ForwardTM 22 Secs 45 Secs 22 Secs ©2013 Akamai
  • 12.
    SPOF – NotOnly Your Homepage Category Page, BazaarVoice down Faster ForwardTM 23 Secs ©2013 Akamai
  • 13.
    Airbnb.ca homepage: SPOFdelays late actions Faster ForwardTM ©2013 Akamai
  • 14.
    New York Page FasterForwardTM ©2013 Akamai
  • 15.
    New York PageSPOF Faster ForwardTM ©2013 Akamai
  • 16.
    The 1st PartyArsenal - Async - Delay onload (async att) vs don’t delay onload (IFrame) - Defer Execution - Defer Download - Remove Tag Faster ForwardTM ©2013 Akamai
  • 17.
    Analytics & Beacons -Goal: Async without delaying onload - Shouldn’t delay visible content - Defer not great since it’s likely to miss users Faster ForwardTM ©2013 Akamai
  • 18.
    Beacons that don’tdelay onload Faster ForwardTM ©2013 Akamai
  • 19.
    Beacons that don’tdelay onload Faster ForwardTM ©2013 Akamai
  • 20.
    Q: Do Script-InsertedBeacon Images Delay Onload? http://stevesouders.com/cuzillion/?c0=bi1dfff2_0_f Faster ForwardTM ©2013 Akamai
  • 21.
    Yes – Beaconsdelay onload (on most browsers) http://www.browserstack.com/screenshots/3c4be740eee4ad95af43ef0fc6a800d7a7aa7758 Beacons didn’t block onload on: - IE 7 - IE 8 Faster ForwardTM ©2013 Akamai
  • 22.
    Works for ImagesToo! Faster ForwardTM ©2013 Akamai
  • 23.
    Analytics & Beacons -Goal: Async without delaying onload - Shouldn’t delay visible content - Defer not great since it’s likely to miss users - Technique: Dynamically generated IFrame - Only works if no page manipulation is required - Catches and what can you do about them - Inline & external script relationships - Event registration Faster ForwardTM ©2013 Akamai
  • 24.
    External Script Cringe… Dependent InlineScript Further Dependent External Script Further down dependent inline script Faster ForwardTM ©2013 Akamai
  • 25.
    Run “inline” scriptat onload Slight Snag… But you catch my drift… Don’t forget this one! (combine all dependents to avoid race condition bugs) Faster ForwardTM ©2013 Akamai
  • 26.
    FYI: Omniture Workarounds FasterForwardTM ©2013 Akamai
  • 27.
    Beacon API –Draft W3C Spec Faster ForwardTM ©2013 Akamai
  • 28.
    Non-Critical Page Components -Goal: Defer Download - If they’re not critical, they shouldn’t content with the rest Faster ForwardTM ©2013 Akamai
  • 29.
    Defer Download Example FasterForwardTM ©2013 Akamai
  • 30.
    Defer Download Example FasterForwardTM ©2013 Akamai
  • 31.
    Non-Critical Page Components -Goal: Defer Download - If they’re not critical, they shouldn’t content with the rest - Catches and what can you do about them - Event registration Inline & external script relationships document.write() Execution order Faster ForwardTM ©2013 Akamai
  • 32.
    Nullify document.write() - Builtinto browsers (at least IE 9+, Safari, Chrome & Firefox) - Firefox even gives a nice console error… Faster ForwardTM ©2013 Akamai
  • 33.
  • 34.
    Critical Page Components -Methodology: Async with blocking onload - Keep 3rd parties from blocking 1st party content - Delay onload as page not complete until component is loaded Faster ForwardTM ©2013 Akamai
  • 35.
    Async with blockingonload Faster ForwardTM ©2013 Akamai
  • 36.
    Critical Page Components -Methodology: Async with blocking onload - Keep 3rd parties from blocking 1st party content - Delay onload as page not complete until component is loaded - Catches and what can you do about them - Event registration Inline & external script relationships document.write() Execution order Faster ForwardTM ©2013 Akamai
  • 37.
    Async scripts withExecution Order Faster ForwardTM ©2013 Akamai
  • 38.
    Interim Summary - Analytics/Beacons– Async without delaying onload - Non-Critical Widgets – Defer Download (and Execution) - Critical Widgets – Async with delaying onload Faster ForwardTM ©2013 Akamai
  • 39.
    Resource Timing Opt-In AskRequire All your 3rd Party Vendors to add this header! - Unless they give you a REALLY good privacy reason not to. Faster ForwardTM ©2013 Akamai
  • 40.
    3rd Party Checklist– Work in Progress… @bentlegen @igrigorik @bbinto @guypod Faster ForwardTM @triblondon Kyle Kinnaman ©2013 Akamai
  • 41.
    Summary - 3rd Partytags are a part of our reality… - Pick your strategies: - Analytics/Beacons – Async without delaying onload - Non-Critical Widgets – Defer Download (and Execution) - Critical Widgets – Async with delaying onload - Track the Beacon & Resource Priorities Specs - Challenge your 3rd party vendors on their perf & availability Faster ForwardTM ©2013 Akamai
  • 42.
    Questions? THIRD PARTY PERFORMANCE GuyPodjarny (@guypod) CTO, Web Experience, Akamai Faster ForwardTM ©2013 Akamai

Editor's Notes

  • #12 http://www.webpagetest.org/video/compare.php?tests=131014_TS_61a4bc3ecbd8a4d1b84e6d3cbf397a3b%2C131014_YR_d9dc75ab1c43d635a8b5d072d92c5830&thumbSize=200&ival=1000&end=visual
  • #13 http://www.webpagetest.org/video/compare.php?tests=131014_DB_563f7c9daf8cbac69641778c7e433764%2C131014_6N_d2f5c727727583b8c4404c8777e60a2a&thumbSize=200&ival=1000&end=visual&font=9
  • #14 http://www.webpagetest.org/video/compare.php?tests=131031_WP_2be372a6f51d099542f5d32317f124eb%2C131031_RT_2cc38c9687c1c0e87bab8dcb36364117&thumbSize=200&ival=1000&end=visual
  • #15 http://www.webpagetest.org/video/compare.php?tests=131101_AR_55144c3188a1273c298b66fb36f134ff-l:MixPanel+Down%2C131031_T0_edd6da0f89972c3fa9321efc60ca58ec-l:Google+Maps+Down%2C131031_06_841a45f9090a02e44ce8510f23703b8a&thumbSize=200&ival=500&end=visual
  • #16 http://www.webpagetest.org/video/compare.php?tests=131101_AR_55144c3188a1273c298b66fb36f134ff-l:MixPanel+Down%2C131031_T0_edd6da0f89972c3fa9321efc60ca58ec-l:Google+Maps+Down%2C131031_06_841a45f9090a02e44ce8510f23703b8a&thumbSize=200&ival=500&end=visual
  • #19 <script>(function(url,tag){variframe = document.createElement('iframe'); (iframe.frameElement || iframe).style.cssText = "width: 0; height: 0; border: 0";var where = document.getElementsByTagName('script'); where = where[where.length - 1];where.parentNode.insertBefore(iframe, where);var doc = iframe.contentWindow.document;doc.open().write('<body onload="'+ 'varjs = document.createElement(\''+tag+'\');'+ 'js.src = \''+ url +'\';'+ 'document.body.appendChild(js);">');doc.close();})('http://3party.com/widget.js','img');</script>
  • #20 <script>(function(url,tag){variframe = document.createElement('iframe'); (iframe.frameElement || iframe).style.cssText = "width: 0; height: 0; border: 0";var where = document.getElementsByTagName('script'); where = where[where.length - 1];where.parentNode.insertBefore(iframe, where);var doc = iframe.contentWindow.document;doc.open().write('<body onload="'+ 'varjs = document.createElement(\''+tag+'\');'+ 'js.src = \''+ url +'\';'+ 'document.body.appendChild(js);">');doc.close();})('http://3party.com/widget.js','img');</script>