Hazard-Free Connection Release

Fault-tolerant communication in a distributed system requires reliable connection management and message delivery. Reliable connection management includes the guarantee of hazard-free release, in which no data is lost before the connection is terminated. Our work focuses on protocols in which the end nodes retain no connection-speci c information between incarnations, operating over networks that deliver packets in order and which may or may not lose packets in transit. In this paper we present a formal model that encompasses the notion of hazard-free connection release. We show that providing a guarantee of hazard-free connection release incurs a penalty over non-hazard-free connection release in terms of message passing overhead if the network does not lose packets. If packet loss may occur, we show that there is no penalty for providing hazard-free connection release, since the connection management protocol must compensate for poorer network behavior.