Using leases to support server-driven consistency in large-scale systems

The paper introduces volume leases as a mechanism for providing cache consistency for large scale, geographically distributed networks. Volume leases are a variation of leases, which were originally designed for distributed file systems. Using trace driven simulation, we compare two new algorithms against four existing cache consistency algorithms and show that our new algorithms provide strong consistency while maintaining scalability and fault tolerance. For a trace based workload of Web accesses, we find that volumes can reduce message traffic at servers by 40% compared to a standard lease algorithm, and that volumes can considerably reduce the peak load at servers when popular objects are modified.