Wide-Area Group Membership for Tightly-Coupled Services

Today’s large-scale services generally exploit looselycoupled architectures that restrict functionality requiring tight cooperation (e.g., leader election, synchronization, and reconfiguration) to a small subset of nodes. In contrast, this work presents a way to scalably deploy tightlycoupled distributed systems that require significant coordination among a large number of nodes in the wide area. Our design relies upon a new reliable group membership abstraction to ensure that either group members are capable of communicating or that new groups form. In particular, we deploy a distributed rate limiting (DRL) service within a global testbed infrastructure. Unlike most distributed services, DRL can safely operate in separate partitions simultaneously, but requires timely snapshots of global state within each. Our DRL implementation leverages our proposed group membership abstraction and a robust gossip-based communication protocol, conjoining the fates of view maintenance and data dissemination. Through local and wide-area experiments, we illustrate that DRL remains accurate and responsive in the face of a variety of failure scenarios.