Bug 202019 – Video Element Progressive Download of MP4 Makes Poorly Behaved Network Requests

• Status: RESOLVED
• Resolution: INVALID
• Component: Media

[Colin McFadden]

Created attachment 379186 [details]
Inspector showing the range requests

We vend MP4 video from AWS S3 buckets, which are displayed using a standard <video> element.  WebKit initially buffers a sizable amount of video from the server, and then closes the connection.  When it needs to load additional data (as playback progresses), it makes a 206 Partial Content request with a Content-Range requesting the entire remainder of the file.  After loading a small amount of data (roughly 2 megabytes in our environment), the connection is aborted.  

Because the content-range request asked for the entire remainder of the file, and because the connection was aborted, this causes excessive billing and data transfer on the server side.  In our environment with AWS S3, a connection in which the WebKit client loads ~2 megabytes will incur ~12 megabytes of billed data.

Ideally would set the content-range more accurately according to the data it actually intends to load, or would maintain a single long-running connection to the server (this is the current behavior in Chrome). 

I can provide a test environment if necessary, but would rather not do so publicly as the testing process could expose us to substantial costs.

[Radar WebKit Bug Importer]

<rdar://problem/55568259>

[Alexey Proskuryakov]

> I can provide a test environment if necessary, but would rather not do so publicly as the testing process could expose us to substantial costs.

Please feel free to e-mail me, I will then add the testing details to an Apple internal ticket.

[Alexey Proskuryakov]

Sorry for the delay. This was determined to be an issue in an underlying framework below WebKit, so we can't track it here. It will continues to be tracked by Apple internally.

I just stumbled upon this issue as well while implementing 'Range' requests in our webserver.

It's quite disturbing to know that this issue probably doubles global internet bandwidth usage and environmental impact! Crazy.