extended direct-view event with ownership

[dannycoates]

closes #2143

[ianb]

I think this needs an update to METRICS.md as well. In that document it should also note that CDNs will greatly deflate this measurement.

[dannycoates]

Are we planning on using a CDN for screenshots? I was under the impression that we'll only be using one for site assets.

[ianb]

Yes, we were planning on using a CDN (under a separate domain name) for individual images, not just site assets.

[dannycoates]

we were planning on using a CDN (under a separate domain name) for individual images

I think there's more work for this that doesn't have tracking issues like invalidating the CDN cache when the conditions used in the query for getRawBytesForClip change (block, delete, expire).

Secondarily, do we have evidence that CDNifying the screenshots will be worth the expense? My uneducated guess is that most shots aren't generally accessed by a large distribution of users. Maybe a simple http cache (nginx, varnish) would be enough. I guess I'm saying I don't understand the expectations / requirements.

cc #2210

[ianb]

You're right, there are important implications to the CDN. @relud did some calculations that using a CDN wouldn't be any more expensive than serving the images directly, even if the images weren't accessed in any volume.

[dannycoates]

There's also the complexity cost. I'm not against it if it makes sense, I just want to understand the cost / benefits.