The Cost of Recovery in Message Logging Protocols

ÐPast research in message logging has focused on studying the relative overhead imposed by pessimistic, optimistic, and causal protocols during failure-free executions. In this paper, we give the first experimental evaluation of the performance of these protocols during recovery. Our results suggest that applications face a complex trade-off when choosing a message logging protocol for fault tolerance. On the one hand, optimistic protocols can provide fast failure-free execution and good performance during recovery, but are complex to implement and can create orphan processes. On the other hand, orphan-free protocols either risk being slow during recovery, e.g., sender-based pessimistic and causal protocols, or incur a substantial overhead during failure-free execution, e.g., receiver-based pessimistic protocols. To address this trade-off, we propose hybrid logging protocols, a new class of orphan-free protocols. We show that hybrid protocols perform within two percent of causal logging during failure-free execution and within two percent of receiver-based logging during recovery. Index TermsÐDistributed computing, fault tolerance, log-based rollback recovery, pessimistic protocols, optimistic protocols, causal protocols, hybrid protocols.