Okay but this is where I get confused. Why does Discord need a single database system when discord servers are independent, right?
And the volume of traffic per Discord server must be human-processable or what would the point be? A Discord server doing 800k writes per second makes no sense.
So why not a RDBMS per Discord server, and if you want to ship all that out to a warehouse for analytics you do that as a separate problem?
Or is it that spinning up a Postgres instance per Discord server ends up being significantly more expensive than these mega distributed database systems?
There are ballpark of a few hundred million discord servers... do you really want to run that many Postgres instances? And even so what do you do about DM/GDMs? Easier to just run one big mega cluster for messages.
Okay so the latter then - economies of scale. Surprised to hear that few hundred million figure - I thought it'd be 1/10th of that at most! Wow.
Although I did expect there'd be a very long tail, and you might choose to host a bunch of servers on a single RDBMS, at that scale yeah it wouldn't solve much.
And the volume of traffic per Discord server must be human-processable or what would the point be? A Discord server doing 800k writes per second makes no sense.
So why not a RDBMS per Discord server, and if you want to ship all that out to a warehouse for analytics you do that as a separate problem?
Or is it that spinning up a Postgres instance per Discord server ends up being significantly more expensive than these mega distributed database systems?