Be General and Don't Give Up Consistency in Geo-Replicated Transactional Systems

We present Alvin, a system for managing concurrent transactions running on a set of geographically distributed sites. Alvin supports general-purpose transactions, and guarantees strong consistency criteria. Through a novel partial order broadcast protocol, Alvin maximizes the parallelism of ordering and local transaction processing. Alvin processes read-only transactions either locally or globally, according to the selected consistency criterion, and orders only conflicting transactions across all sites. We built Alvin in the Go language and conducted an evaluation study relying on the Amazon EC2 infrastructure and Paxosand EPaxos-based state machine replication protocols as competitors. Our experimental results reveal that Alvin provides significant speed up for read-dominated TPC-C workloads and on 7 datacenters by as much as 4.8x when compared to EPaxos, and up to 26% in write-intensive workloads.