PRACTI replication for Large-Scale Systems

M. Dahlin, L. Gao, A. Nayate, A. Venkataramani, P. Yalagandula, J. Zheng

We present the first PRACTI (Partial Replication, Arbitrary Consistency, and Topology Independent) replication toolkit. PRACTI mechanisms can replicate or cache any data on any node (PR), provide a broad range of consistency and coherence guarantees (AC), and permit any node to communicate with any other node at any time (TI). Compared to existing mechanisms that force a system designer to compromise a system's replication, topology, or consistency policy, PRACTI yields two significant advantages: flexibility and improved trade-offs. PRACTI's flexibility simplifies the design of replication systems by allowing a single framework to subsume a broad range of existing approaches. At the same time, PRACTI provides better trade-offs than the point-solution policies embedded in existing mechanisms: for workloads of interest, our PRACTI design dominates existing approaches by providing an order of magnitude better bandwidth and storage efficiency than replicated server systems (AC-TI), an order of magnitude better synchronization delay compared to hierarchical systems (PR-AC), and consistency guarantees not achievable by per-object replication systems (PR-TI).

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