How to detect if the page is slow due to 3rd party javascripts?

Question

For those of us who run content websites and deal with Ad networks, combating malicious or malfunctioning rogue ads can be frustrating.

I own a site that embeds a lot of Youtube & Dailymotion videos. Once in awhile, a bad Ad will turn up and make the video playback stutter. I always dealt with these on a case-by-case basis. But, is there a way to detect (using javascript) whether or not the page is slow?

In my head, a very crude way is to have a setInterval running at 100ms. And if it detects a big delay in one interval, act accordingly.

Are there other more elegant approaches?

Answer 1

First approach, if your slowness is on load, create placeholders for the ads and load them very last after everything else.

Second approach, create a Javascript timer or include a timer library to measure the page load time. If it is greater than your acceptable threshold then kill the ad with Javascript or log the slowness to a web service.

Third approach, if the timer does not pick up the slowness because it is incremental then use a setTimeout function that records a timestamp and calls itself every 200ms and compares the new timestamp each call to the older timestamp from the previous call.

If a setTimeout call set to run at 200ms takes 500ms to finally run then you've got substantial delay and should kill the ad with Javascript or log the slowness to a web service.

Each of these methods will need to be tuned to your actual site.