A Lazy Monitoring Approach for Heartbeat-Style Failure Detectors

Failure detectors are a fundamental part of safe fault-tolerant distributed systems. Many failure detectors use heartbeats to draw conclusions about the state of nodes within a distributed environment. The contribution of this paper is an approach whose benefits are twofold. On the one hand it reduces the network overhead produced by heartbeat-style failure detectors. On the other hand it improves the quality of these failure detectors by providing them with richer information about the current network condition. We call this approach lazy monitoring since the active sending of heartbeats is avoided if possible. As it is independent of the actual failure detection algorithm it can be used in many domains. For evaluation purposes we applied our approach to the Smart Doorplate Project. In this testbed the proposed technique reduced the traffic to 1.2% while providing much more information about the environment to the failure detectors.