Automatic Web performance measurement

Philippe Le Hégaret, W3C
for Radware

Automatic Web performance measurement

Motivation
Challenges
Proposed Solution
PLH's Open Questions

Motivation

Performance has direct impact on customer satisfaction
Navigation and Resource Timing gives visibility to user experience
- Early identification of the problems and taking preventive actions.
- Adjusting the resource content to the current session
- Analysis of the application page and redesign if needed

Challenges

APM automatic insertion of Javascript code in a Web page can change the Web page functionality
Javascript code will affect the page performance
APM cannot insert Javascript codes in malformed resources

Radware Proposed Solution

HTTP Header
HTML content attribute
Performance information
Communication protocol

New HTTP Header

Performance_Reporting_Target: <URL for reporting>

If present, send the report at the given URL

HTML content attribute

Content attribute: perfcollect

The perfcollect is a boolean attribute that indicates if Navigation Timing (for <body> element) or Resource Timing performance information should automatically collected and reported.

For elements like <body>, <a>, <div>, <img>, <object>, <video>, <link>, etc.

Performance information

Cf the properties from the PerformanceResourceTiming interface (Resource Timing):

readonly attribute DOMHighResTimeStamp redirectStart;
readonly attribute DOMHighResTimeStamp redirectEnd;
readonly attribute DOMHighResTimeStamp fetchStart;
readonly attribute DOMHighResTimeStamp domainLookupStart;
readonly attribute DOMHighResTimeStamp domainLookupEnd;
[...]

Communication protocol

POST /enlighten/calais.asmx/Enlighten HTTP/1.1
Host: api.opencalais.com
Content-Type: application/x-www-form-urlencoded
Content-Length: length

resource=name_of_resource1
resourceURI=URI_of_resource1
redirectStart=timestamp
redirectEnd=timestamp
fetchStart=timestamp
[...]

resource=name_of_resource2
[...]

PLH's Open Questions

The APM still has to modify the Web page?
How to activate automatic measurements to resources like XHR, @import?
JSON format instead of x-www-form-urlencoded?
Should it be under same origin policy?
Other security consideration?