Common knowledge on C* heap size/file _cache_size_in_mb/other RAM usage parameters

[Vsevolod Filaretov <vs...@gmail.com>]

What are general community guidelines on setting up C* heap size,
file_cache_size_in_mb, offheap space usage and other RAM usage settings?

Are there any general guidelines like "if your total data size per node is
X/median/max partition size is Y, your RAM usage settings better be Z or
things will be kinda slow"? If no - are there any ways to deduce such
values other than trial-and-error?

Our case: 2.4 tb/node, median partition size 340mb, max partition size 2Gb,
and we can't concider partition schema changes.

Thank you.