Currently you can get cluster wide information using different endpoints for different means. The node info API will return static information with respects to nodes (like jvm versions). The node stats API will return dynamic information (like memory and cpu usage) and the index stats API will return aggregated (and per index) information regarding the cluster data.

With the new Cluster Stats API, we will have a single endpoint that returns all the information needed to get an overview of the cluster. The output will contain basic index metrics (shard numbers, store size, memory usage) and information about the current nodes that form the cluster (number, roles,os, jvm versions, memory usage, cpu and installed plugins).