System Design ( Day - 24 )

How Netflix onBoards new Content at Scale

Requirements
1. Different Formats of Videos
a. High Quality
b. Medium Quality
c. Low Quality all of these are codec
2. Different Resolution
a. 4K
b. 2k
c. 1080p
b. 720p
…
These Videos are usually long for this they divide them into some chunks and create a scene with the chunks and sends to the user for processing, while playing if user gets any loading then that scene is not loaded properly.
if the user is skimming the video then that request will be send by the netflix server, it won’t send the complete, it will send only asked scenes, if the video is watched completely then in that case the server will send each scene one by one, through buffer it will load the video in to the video player

These videos are stored in the S3 in a file system while processing the video the server will get the chunks and send it to the user as scene, so that the device can process that scene before getting buffered or loading, these storage is in some place of the region like these S3 could be in US or UK or in india, but while loading the videos the server has to go to that S3 storage every time get the data, that is a huge delay it shouldn’t be there, for that we need caching to store that data near to the user.

What netflix does is, whenever there is popular movies or series uploads then it will cache it in the nearby caches, whenever there is a request for the same movie then the request won’t goes to the Netflix server present in the US, instead of that it will goes to the Cache to access it fast. in this case it could be open connect cache it could be something like a HardDrive, in this case when the user is making the request then the ISP will hit the open connect cache checks for that movie if it’s there then it will return the movie,
this would reduce the network calls that has to be goes to the netflix server every time.

whenever there is a update for the open connect, we can do it with non-peek hours like around 3-4am in the morning to maintain the user experience, By this way through caching and by video processing through chunks netflix made the video streaming seamless.