Criticize the video content delivery architecture?

Question

Video broadcast

Good afternoon,
There is a video delivery scheme (over the HLS protocol) that I want to use in my project.
I was completely confident in it, until some made me doubt it (although I think in vain, but I want to hear the opinions of others)
Its meaning is as follows:
We have a video, we encode it in 3 qualities:
* 720p (up to 4Mbit \\ sec, - max segment size about 6MB)
* 360p (up to 1Mbps, - max segment size 1.5MB)
* 240p (up to 500Kbit/sec, - max segment size 0.6MB)
After This is broken into pieces lasting 10 seconds. (apple recommendation) and spread across all servers:
Segments are evenly distributed across nodes, i.e.:
* segments from 0 seconds to 10 seconds in 3 qualities are stored on the first node
* segments from 10 seconds to 20 seconds in 3 qualities are stored on the second node
* segments from 20 seconds to 30 seconds in 3 qualities are stored on the third node
, etc.
When there are more segments than nodes, they are stored in a circle.
In addition, each node has its own duplicate, which stores a complete copy of its node.
Those. very similar to RAID 51
When a client comes to watch a video, he gets to the first node, downloads (if the network speed = him + node) the largest segment (hd quality), then the request goes to the second node, the segment is taken from there, then from the third etc.
In case of network "sagging" on a node, it gives segments in a low bitrate.
Duplicate node can also give segments. (there is a balancing between the node and the duplicate, i.e. they receive an equal number of requests)
Advantages:
No problem of hot videos, because it is spread across all servers.
You can add nodes horizontally to infinity
. I'll attach a picture for every firefighter
. What are the shortcomings of this scheme in your opinion?
Thanks

Answer 1

Criticize so criticize) Why didn’t they do it before you.
The idea is cool, but there are already more interesting implementations for these purposes - distributed file systems (if all the equipment is relatively close) or CDN (if far away)

Answer 2

From myself I will add that in my opinion it is necessary to approach the issue of "hot" and "cold" videos more intellectually. Although of course it depends on the project very much.
The guys from erlyvideo said that ~80% of the traffic on karamba.tv is traffic per video in the first day after it was uploaded. That is, a really hot video is spread out in full takes on N servers for a quick return. Everything else is stored conditionally with normal reservations.