Druid Caching not working correctly

Hello everybody,

I’m new in Druid universe , deployed the solution on Kubernetes cluster it’s work’s fine. but when i turn on cache on both historical and Broker then one by one but cache seem not working . any idea ?

Thank you in advance.

Hey! Glad you’re joining us!!!

First, in prod use only caching on HIstoricals
https://druid.apache.org/docs/latest/querying/caching.html

Second - when you say it is not working, what kind of things are you seeing?

Also remember that lots of RAM on Historicals = good. THey will memory map the actual segment files. I’ve heard of people even having 1:1 between the segments on a node and their RAM…!!

Hello,

Thank you for your answer , i tried groupBy queries . and i think the problem is using high cardinality columns in the queries . it’s seem druid don’t like this . you confirm ?

Aha! Well of course you know I will say NO it’s FINE!! haha :slight_smile: Can you tell more about the query you are executing on those dimensions?