Server Selection Using Dynamic Path Characterization in Wide-Area Networks

Replication is a commonly proposed solution to problems of scale associated with distributed services. However, when a service is replicated, each client must be assigned a server. Prior work has generally assumed that assignment to be static. In contrast, we propose dynamic server selection, and show that it enables application-level congestion avoidance. Using tools to measure available bandwidth and round trip latency (RTT), we demonstrate dynamic server selection and compare it to previous static approaches. We show that because of the variability of paths in the Internet, dynamic server selection consistently outperforms static policies, reducing response times by as much as 50%. However, we also must adopt a systems perspective and consider the impact of the measurement method on the network. Therefore, we look at alternative lowcost approximations and nd that the careful measurements provided by our tools can be closely approximated by much lighter-weight measurements. We propo...

• Type: Conference
• Year: 1997
• Where: INFOCOM
• Authors: Robert L. Carter, Mark Crovella
• Keywords: Alternative Lowcost Approximations, Application-level Congestion Avoidance, Communications, Dynamic Server Selection, INFOCOM 1997