Increasing the default number of resources to report on in Resource Timing

Document created by DPM Admin Employee on Jul 14, 2017Last modified by B-F-F08DRX on Jul 20, 2017
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With the introduction of the Waterfall Analysis dashboard, mPulse gives you the diagnostic power to drill deeply into individual page loads to examine resource-level performance and behaviors.  The "waterfall" style graphs let mPulse users see how individual assets on a page (such as the images, CSS files, and Javascript files  used for that page) are loading between the time that the page was requested and the onload event.  This data is collected directly from the user's browser using the W3C Resource Timing API.


One limitation that site operators should be aware of is that the W3C Resource Timing API has a limited buffer size for resource data collection.  By default, the API specifies that compliant browsers should collect data for the base document request and at least 150 individual assets on the page. Fortunately, there is  a method available in the API that can be used to specify a buffer size higher than 150, called setResourceTimingBufferSiz


The following is a sample code snippet you can insert into your site's HTML to increase the buffer size to 300.  For more details, see:


if ("performance" in window && window.performance) {    
   if(window.performance.setResourceTimingBufferSize) {        
   else if(window.performance.webkitSetResourceTimingBufferSize) {