By "small" I mean that currently I have a 6x m1.xlarge instances running Cassandra 3.0.17. Total amount of data is around 1.5TB spread across couple of keypaces wih RF:3.
Over time few things happened/became clear including:
- increase amount of ingested data
- m1.xlarge instances are somehow outdated. We noted that one of them is under performing compared to the others. Networking is not always stable/reliable and so on
- Upgrading from 3.0.6 to 3.0.17 emphasized the need of better hardware even more (in my opinion).
Starting from here I believe that i3/r5d are already a much better option to what we have with a comparable price.
About the EBS: Yes, I am aware its performance is related to its size (and type) That is the reason why I was looking into a 600/900GB drive that already a much better option compared to our raid0 of spinning disks. Both i3 and r5d are EBS optimized