I've got a Hot/Warm infrastructure. 4 Hot and 4 Warm nodes, 16GB RAM each. I've set a 7GB of HEAP on each node but I've got a question regarding HEAP on WARM nodes:
If WARM nodes are used only for storing older data, would it be a good idea to actually decrease heap size and leave more memory for Buff/Cache? It seems those Warm nodes aren't using Heap too much, like 20% is their maximum use but they do use Buff/Cache RAM a lot.
Edit: Also those Warm nodes are not used directly for Queries, Hot nodes are.