| The problem with this article is that it starts out with great examples, but then failed to actually provide the utility of it because the assumptions are off compared to reality. Fagpacket maths is great for specific problems, Can I make a mobile bridge, What price should I sell product x at. But all these examples have hard and agreed upon constraints. The example fails because the author doesn't appear to have worked with systems of a big enough scale to make good assumptions. Once you start hitting petabytes its way way way cheaper to do on prem. The issue becomes one of backup and retrieval speed (which they touch on) The reason why this is important is because for this fagpacket calc to work, you need to know the rough price per meg for storage of each asset class(and its purpose, ie, for machine learning, serving the CDN, for logs etc etc). Tweets will be stored differently from pictures, and pictures will be different from video. Archiving is impractical for an always on system (ie all old tweets and media need to load within 150ms) The other big issue here is that caching is never really mentioned here. CDNs will be one of the bigger costs for twitter. The more efficient caching is, the less your raw storage costs are. TLDR:
Fagpacket maths is great, but you need to know your constraints and parameters first. Otherwise you'll endup with wildly incorrect numbers. |