Horizontal scaling

[bakape]

• Need to asserts server version through some means and not communicate with instances of same version. Considering the variations possible both in the system and externally, a cache should have a manually set name and version. If not set, no horizontal scaling is performed.
• Consider, if static or dynamic sharding by hash is better.
• Consider, if this useful at all, considering the extra I/O costs. Opting for only vertical scaling might be more optimal.
• Consider how to handle a client requesting a key belonging to a foreign shard.