NewCache creates a new cache.

NewKeyCache creates a new KeyCache each clearInterval, all shards will be wiped (one at a time, spread out over the interval).

NewShard creates a new shard.

Cache is a single-tenant keycache it is sharded for 2 reasons: * more granular GC (eg.

KeyCache tracks for all orgs, which keys have been seen, and when was the last time.

Shard tracks which SubKey's have been seen since the last prune.

SubKey is the last 15 bytes of a 16 byte Key We can track Key-identified metrics with a SubKey because we shard by the first byte of the Key.