Cassandra - Row cache tuning

Question

I'm new to Cassandra and trying to get a better understanding on how the row cache can be tuned to optimize the performance.

I came across think this article: https://docs.datastax.com/en/cassandra/3.0/cassandra/operations/opsConfiguringCaches.html

And it suggests not to even touch row cache unless read workload is > 95% and mostly rely on machine's default cache mechanism which comes with OS.

The default row cache size is 0 in cassandra.yaml file so the row cache won't be utilized at all.

Therefore, I'm wondering how exactly I can decide to chose to tweak row cache if needed. Are there any good pointers one can provide on this?

Answer 1

What they are saying in this article, is that OS cache is better than row cache.

Cassandra's rows cache known as not efficient for most cases. The only case i see you can even start trying, is that 95% of your workload are reads + you have a relatively small set of hot rows that are not updated frequently.