OK, there is certainly something strange going on and it appears to be rate-limit related.
I’m not sure if we’re being rate-limited because I did a massive rebake and we’ve gone on the naughty step, or if we’re tripping limits that others will see.
Oneboxing of YouTube videos seems to have a limit and once that limit is reached the Oneboxing fails silently.
I feel this has to be changed for hopefully obvious reasons, but specifically for anyone that does a migration or rebake that will have no idea that lots of un-expanded or once-expanded Oneboxes are now just vanilla URLs.
@marcozambi mentioned above that the YouTube URL format that features /embed/ before the video ID works when the other formats are failing (presumably due to a rate-limit issue).
Here’s a video that illustrates that phenomenon well.
When this screencast was captured, there were no jobs clogging the queues and the forum was otherwise performing well.
Prior to this video, YouTube links had already started to fail to be expanded by OneBox.
What you will see is the compose window where Onebox fails to expand a YouTube link in the https://youtu.be/<video-id> format.
I then change the format to be in the https://youtube.com/embed/<video-id> format and Onebox expands it.
I then try again with the original format and it fails.
During this video capture, I tracked the browser console and network tabs. I recognise that the issue is surely between our server and YouTube rather than between my browser and our server, but I include them below in case they are useful.
(apologies for the zoomed-out nature of the image - I hope they’re visible when zoomed-in)
And here is the network trace when the Onebox worked.
