Ok.
First things to check, wether your machines can be equiped with SSD drives... several per maschine.
with ssd drives you can achive more than 10000/s per Hardware node... and maybe more... but it depend on many things...
Here look at discussion with spinning disks.:
Let's assume you will make 20000/s per Hardware node (2 Elasticsearch instances in Docker) then you need at least 10 Hardware nodes to deal with your peaks... But 200.000 /s is huge number, so much other apps and custom tools can have problem before Elasticsearch...
But again 2 billions a day is huge number, in best case you start with 1/10 of this on smaller set and test how it behaves and scalles...
Check this:
More questions
- what happens if you're cluster can't index 200.000 for 2 minutes, and starts rejecting bulk index request? How does your application react? Is it custom app?
Logstash for example can deal with that...