i'm releasing a new one 27 may called replicatr

it has a storage management cache capability and can be interfaced with a second level (distributed, possibly immutable) data store

it already can do live subscriptions as it's based on khatru, but i have massively rewritten the nostr library, the relay logic and the event store

it uses badger, and i am right now in the middle of completing a revision of the garbage collector which currently can measure utilization of the store in 8 seconds for a 14Gb of event data and should be viable for up to a terabyte with some tuning (later i plan to make a self-tuning GC timer with dynamic metadata calculation)