SolrCloud doesn't provide any aggregate stats about the cluster or a collection. Very common questions such as document counts per shard, index sizes, request rates etc cannot be answered easily without figuring out the cluster state, invoking multiple core admin APIs and aggregating them manually.
I propose that we expose an API which returns each of the following on a per-collection and per-shard basis:
- Document counts
- Index size on disk
- Query request rate
- Indexing request rate
- Real time get request rate
I am not yet sure if this should be a distributed search component or a collection API.