Date Added: Jun 2010
Zzyzx is a Byzantine fault-tolerant replicated state machine protocol that outperforms prior approaches and provides near-linear throughput scaling. Using a new technique called Byzantine Locking, Zzyzx allows a client to extract state from an underlying replicated state machine and access it via a second protocol specialized for use by a single client. This second protocol requires just one roundtrip and 2 f+1 responsive servers - compared to Zyzzyva, this results in 39 - 43% lower response times and a factor of 2.2 - 2.9? higher throughput. Furthermore, the extracted state can be transferred to other servers, allowing non-overlapping sets of servers to manage different state.