After a chunk is split, a split event will be recorded in the config.changelog collection. Currently the shard name & server name recorded in this changelog is the replica set of CSRS and host:port of the CSRS primary.

	"_id" : "CSRS_primary_host:CSRS_primary_port-XXX-YYY",
	"server" : "CSRS_primary_host:CSRS_primary_port",
	"shard" : "config",

It would be nice if the shard name & server could be the shard that owns the chunk. This would help to check the split activities on the shards and might help to identify hot shards etc.