Carla wrote:Can you explain how the %k value from the SaveRecord command is calculated? I'm trying that on an AJAX page and I get strange results...
The
%k parameter in the SaveRecord command records the total number of bytes downloaded beginning with the completion of the last command, up to and including completion of the current command.
If you are getting strange results on an AJAX page, well, with respect, we need to point out that you DO have an AJAX page and, well, sorry to say this, but that's what AJAX pages do.
Here are some more details that may help explain the situation:
* eValid senses completion of the download by examining a set of internal signals (triggers) that,
in combination, indicate that download is complete.
* eValid measures byte counts of each page component by effectively putting a wrapper around each download thread (there are multiple threads during the download process, not just the "main thread"). That wrapper records the amount of time taken and the number of bytes passed through that wrapper. That's where the page component details come from when you have Deatiled Timings turned ON.
* After the page is completed -- that is, after one of the built-in combinations of signals has been seen -- eValid then computes the value that is will present as the value of the
%k parameter. This same value is put in the EventLog to indicate the total number of bytes downloads as the result of that navigation.
* In the case of AJAX, there could be (and often are) additional JavaScript programs that run -- asynchronously, because it is, after all, AJAX. These JavaScript programs can command download of additional data. But because these little JavaScript programs (and in some cases they are NOT so little!) run inside the browser AFTER the page download is completed, they do NOT show up in the
%k parameter value that SaveRecord writes.
* One technique we've used to measure these "extra" parts is to have an eValid command run the JavaScript program manually. The eValid command
CallJavaScript will to this for you, when you supply it with the name of the JavaScript function/method that you want to run. The data volume for the result of that JavaScript execution is shown as the "bytes downloaded" for that command.
eValid Support
by Carla » Mon Apr 23, 2012 2:09 pm