Surviving Congestion in Geo-Distributed Storage Systems

We present Vivace, a key-value storage system for web applications that span many geographically-distributed sites. Vivace provides strong consistency and replicates data across sites for access locality and disaster tolerance. Vivace is designed to cope well with network congestion across sites, which occurs because the bandwidth across sites is smaller than within sites. To deal with congestion, Vivace relies on two novel algorithms that prioritize a small amount of critical data to avoid delays due to congestion. We evaluate Vivace to show its feasibility and effectiveness.