The image here appears to be upside down (or rather rotated 180): https://github.com/nubskr/nubmq/blob/master/assets/architect...It's not clear from the readme physically where the data is stored, nor where in the storage process the "congestion" is coming from.I'm surprised there's no range scan. Range scans enable a whole swathe of functionality that make kv stores punch above their weight. I suppose that's more rocksdb/dynamo/bigtable/cassandra than redis/memcached, though....