ES Heap and CPU Usage - bigger is better?

Hey guys, i´l just want to ask here if anybody has some better experience with bigger java heap sizes than me. Our problem is that we only have 1 big server with 256 gb RAM and 64 for our ES system which indexes about 4-6k events/s. Actually i have running 3 instances, 2 with 32 GB java heap

Cache API Commands - _nodes/_aliases

Hey guys, Is there actually a way that elasticsearch can cache some API requests in memory, so that they dont have to be loaded from disk every time? E.g. If you open a ES stored dashboard in Kibana, Kibana is execurting curl syslogserver:9200/_nodes and after that curl