Toward Session Consistency for the Edge
USENIX Workshop on Hot Topics in Edge Computing (HotEdge 18), Boston, MA, July 2018
We describe a distributed datastore tailored for edge computing that provides session consistency between otherwise eventual consistent replicas. Existing solutions for session consistency assume that the client is associated with the same replica through a session. However, in edge computing use-cases, a client interacts with multiple replicas housed on different datacenters over time, either as a result of application partitioning, or client mobility. Our core algorithmic innovation is our client reconciliation algorithm that enforces session consistency by tracking and migrating only the client-affected keys between the replicas. Our results show that our approach provides session consistency at a fraction of the latency and bandwidth costs of a strongly consistent system, and with reasonable migration costs.