Cool! So maybe we could roll with something like Celluloid's RingBuffer, adding the ability to scan from the most-recent item to the oldest?

Actually, @vanstee write a tiny, context specific, buffer for just this use case: https://github.com/vanstee/grocer/blob/connection-pool/lib/grocer/history.rb. Or @alindeman has [circular_queue](https://github.com/alindeman/circular_queue/) which we could use as a basis?