Accurate Timeout Detection Despite Arbitrary Processing Delays

Timeout is widely used for failure detection. This paper proposes SafeTimer, a mechanism to enhance existing timeout detection protocols to tolerate long delays in the OS and the application: at the heartbeat receiver side, SafeTimer checks whether there are any pending heartbeats before reporting a failure; at the sender side, SafeTimer blocks the sender if the sender cannot send out heartbeats in time. We have proved that SafeTimer can prevent false failure report despite arbitrary delays in the OS and the application. This property allows existing protocols to relax their timing assumptions and use a shorter timeout interval for faster failure detection. Evaluation shows that the overhead of SafeTimer is negligible and applying SafeTimer to existing systems is easy.