The video is on a cdn and is highly cacheable. The comments are highly dynamic and rely on far more db fetches presumably. You'll notice Google put these under the fold and dynamically ajax them in when you scroll down because they are probably actually expensive on the actual app servers or some resource. The devil is always in the details.
Re:YouTube removes all_comments feature
by ppergame on Monday February 08, 2016 @12:58PM
(#11059689)
The main resource is client bandwidth; it's preferable to spend it on loading media and not the below-the-fold comments.
Re:YouTube removes all_comments feature
by nvrsummer on Sunday February 07, 2016 @08:14PM
(#11055896)
You can transfer less through ajax and render using templates already on the client side instead of using unnecessary bandwidth... They are concerned about showing ALL comments at once I was referring to a paging system for a fall back system. I'm sure it's costing them more than necessary to be allowing all comments to return when you have an immense amount comments on a video.
Forums since the early days of the Web could do this too - only showing the first n posts, and paging to let you view more. And they didn't require JavaScript or any of the other fancy new features browsers have today.
Edit: How much bandwidth would be taken up by loading a few hundred plaintext comments, keeping in mind this is a YouTube page containing an embedded video which will be at least an order of magnitude bigger?
As well as having a back fall system for users with browsers that cannot support such functionality.
That's what all_comments was.