We are currently running a 20 data nodes cluster on AWS EC2 instances.
Since we have only 1 replica per shard, and we cannot tolerate failure of more than 1 node at the time, we are not using ephermal storage but GP2 EBS volumes for the nodes.
With AWS Saving Plans, we have noticed that the EBS costs are most significant from the entire cluster price, so we are considering of volume type change (as we cannot decrease the cluster size).
Does anyone have experience with clusters running with ST1/SC1 EBS types, and can share some of his insights?
I did see this article (https://logz.io/blog/benchmarking-elasticsearch-magnetic-ebs/) that says in general that in terms of writing, SSD were better but in terms of reading, HDD actually gave better results.
But since this article is pretty old now I would like to hear some more about this planned operation we are considering.
Thanks in advance,