ksteve wrote:What is the typical overhead in CPU percent for a synchronization step that has to interrogate the DOM?
Your instinct to ask this question is correct. Nothing is "free" and when eValid interrogates the DOM to confirm that a particular element property has a particular value that does take some CPU time.
If you interrogate too rapidly, you could (in theory) load the CPU so much that you could interfere with the normal operation of the browser.
When we were deciding on the maximum allowable rate for the synchronization loop, we chose set the
MINIMUM INTERVAL at 10 msec.
That results in a retry rate of 100 Hz, or a wait of at most 0.01 seconds after every try.
We measured eValid CPU utilization at this rate and we found that the extra CPU effort was just barely measurable. (It does begin to be a factor if you tried to go faster than 100 Hz and you have 100's of browser-users running in parallel.)
Is 100 Hz -- the maximum rate allowed by eValid -- fast enough? The answer turns out to be yes, because in user-time the response rates for a typical AJAX application are measured in seconds -- 100's to 1,000's of times longer than the synchronization retry interval.
eValid Support
by ksteve » Thu Nov 17, 2011 5:33 pm