DONAR

Purpose

With the advent of cloud computing and the growth of popular Web services, many networked services are replicated at multiple geographic locations.  Such distributed services face the challenge of server selection — that is, directing an incoming client request to the appropriate server or data center, in the hope of reducing network latency or carefully tuning server loads. To meet these potentially conflicting goals, existing approaches use heuristics or rely on central coordination to perform server selection.

DONAR is a distributed system that provides name resolution and server selection for replication services.  It  applies optimization theory to derive a simple, provably optimal, fully distributed solution to the server-selection problem. DONAR defines a global objective for a mapping service, and shows that decentralized mapping nodes performing small amounts of local computation and sharing limited information, can achieve the global objective.

Users

DONAR provides server selection for Measurement Lab, an open-source research platform co-sponsored by the New America Foundation’s Open Technology Institute, The Planet Lab Consortium, and Google Inc. This includes those services being tested by the U.S. Federal Communications Commission (FCC) for broadband measurement and analysis.  DONAR also hosts server selection for CoralCDN, a free, widely-distributed content distribution network.

DONAR is in a beta deployment phase, and users interesting in using DONAR for their DNS, HTTP, or other server-selection needs are invited to contact us for access.