Analysis of an anycast based overlay system for scalable service discovery and execution

Support for anycast in the IP network layer allows one source node to contact a single member out of a group of destination nodes configured with the same IP address. Due to the stateless nature of the IP protocol, subsequent packets from the same source node targeted at the same anycast group may arrive at different group members. Consequently, native IP anycast cannot be applied directly to support distributed session-based services. For this reason, an anycast overlay architecture combining the transparency offered by native anycast with support for stateful communications has been proposed. In this paper, we investigate the operational impact of deploying this overlay architecture. Performance evaluation of a data plane prototype implementation for an anycast overlay node shows that high throughput and small latency can be achieved. Additionally, we show how threshold-based update triggering, in combination with an appropriate inter-proxy update strategy, delivers control plane accuracy with minimal network overhead.