Cluster of 3 cassandra nodes as a dev environment. Used to run in AWS on i3.2xlarge; migrated as a test to i3en.2xlarge to evaluate for later migrating production cluster to.
When running cassandra-stress benchmarks for large row counts (e.g. 100M and 1B), I am seeing an increase in write performance of 80-90%, but a decrease in read performance of around 80%. Minimal or no external traffic to the cluster during these tests.
I have checked the keyspace created by cassandra-stress for excessive SSTables, and there doesn't seem to be any problem there. Running iperf and I/O benchmarks on the new i3en nodes shows a 30-120% increase in performance over the i3 depending on the benchmark.