It would be desirable in a Solr Cloud configuration if a request like:
only executed on the shard that received the request.
As is well known force merging is a very expensive/disk space hungry operation and hence this increased control should address the following issues:
Free disk space requirements: 1-2x size of ALL shards on the machine vs 1-2x size of largest shard
I/O: High disk contention when a machine holds multiple shards as all shards are being simultaneously rewritten
Availability: All replicas will simultaneously have impaired performance
Relevant previous issue: