Engage EMEA 2010 - Data Collection Performance

Data Collection Performance

Bruce Kenny, WebtrendsEric Butler, Webtrends

Data Collection PhilosophyAlways on

High Performance

Webtrends Data CollectionWebtrends On Demand global data collection footprint

Globally distributed DNS to ensure the fastest response for first requests

Regional data centers to provide optimal response times

Data collection traffic is load balanced across data centers to ensure the fastest response for each individual visitor

Stay currentThe Webtrends Tag Builder is updated regularly with enhancements and fixes.

Keep current with the latest HTML and JavaScript generated by Webtrends to best leverage this powerful functionality

Release notes from the most recent update:http://releasenotes.webtrends.com/on-demand/category/

tagbuilder/

New Asynchronous Functionality

Updating Webtrends JavaScript

Leveraging newer standards

Increasing page load performance

New Asynchronous Functionality

JavaScript improvementsUsing javascript to populate variables into a queue until the Webtrends javascript is ready to use them

New JavaScript functionalityLeveraging the HTML5 attribute "async" to allow the javascript to be loaded asynchronously to the rest of the page load

New Asynchronous Functionality

Webtrends innovationIntroducing a new callback method for the cross-domain "wtid.js" callback, allowing for that call to be non-blocking to the rest of the page load

Webtrends performanceDecoupling of the cross-domain "wtid.js" callback, allowing Webtrends to host that functionality closer to visitors

Performance Improvements

Current

AsyncSolution

Resources•Webtrends Tag Builder

http://tagbuilder.webtrends.com/•Webtrends Developer Network

http://developer.webtrends.com/•Webtrends SDK Documentation

http://product.webtrends.com/DC/iphone/index.html

http://product.webtrends.com/DC/android/index.html

http://product.webtrends.com/DC/blackberry/index.html

Technical FAQsWhat about pre-HTML5 browsers? The async tag allows the “code” to be executed asynchronously for browsers that support HTML5.  But because we are also attaching the script-file to the DOM on older browsers we don’t stop the parser/render.   But the DOMContentLoaded (aka onload) event will be held up for pre-HTML5 browsers.  This is still a performance increase since the downloading of the tag happens in parallel to the page rendering.  

Technical FAQsIf the tag is being loaded Async and I have hard-coded dcsCollect and dcsMultitrack calls doesn’t this introduce a race-condition? No, because all commands will be pushed into a queue (JavaScript array).  And the tag will start pulling from that queue when the WebtrendsTag is instantiated and ready for processing (e.g. after it’s finished loading the WT.co_f param from the cookie or wtid.js).  

Technical FAQsDo we still place the tag at the bottom of the Body tag?

No, you should place the tag in the Head tag.  Since you want the process to begin as early as possible.  For low bandwidth devices (like smart phones) this gives you a better chance of registering the hit if the user clicks a link before the pages has finished loading.   We are still doing performance testing to find the optimal place in the head to place the tag (if it should be one of the first scripts or one of the last scripts).  

Technical FAQsWill the async tag be usable from Flash?

Yes, but any existing  Flash(External Interface) calls will need to be modified to push items onto the queue instead of calling our existing dcsXXX methods. 

What happens if the call to wtid.js is unreachable for some reason?

Nothing…  No error, no hits, no wasted CPU cycles, just nothing…