On the Performance of Quorum Replication on the Internet

Replicated systems often use quorums in order to increase their performance and availability. In such systems, a client typically accesses a quorum of the servers in order to perform an update. In this paper, we study the running time of quorum-based distributed systems over the Internet. We experiment with more than thirty servers at geographically dispersed locations we evaluate two different approaches for defining quorums. We study how the number of servers probed by a client impacts performance and availability. We also examine the extent to which cross-correlated message loss affects the ability to predict running times accurately from end-to-end traces.