We are on cassandra 3.7 version We have a 8 node production cluster, with 4 nodes each across 2 DC The RF is set to 3 currently, and we have 2 large tables with upto 70Million rows
We just upgraded our Production cluster from 4CPU , 12 GB RAM to 8 CPU 32 GB Memory. Accordingly we increased our Heap Size to 8GB per the recommended guidelines. 4 boxes in one Datacenter show 2 to 3gb of free memory, but we have 3 nodes in 1 datacenter that show free memory between 600MB and 200 MB only. The heap on the boxes is being reclaimed and we have no special off heap setting, we use the defaults. Is this something we need to be concerned with where 1 node has around only 200MB free? Is there any settings that we might have to look for to increase the free memory?