CLMD: Making Lock Manager Predictable and Concurrent for Deterministic Concurrency Control

Abstract

Transaction processing is common in our daily lives, and various protocols have been studied to manage concurrency control. One such protocol is the deterministic concurrency control protocol, which is highly efficient in handling workloads with high contention because of its deterministic transaction scheduling nature. This paper introduces a new lock manager, the concurrent lock manager for determinism or CLMD. CLMD allows non-conflicting transactions to be executed concurrently on deterministic concurrency control protocols. The concept is to check for conflicts between the current and all future transactions while the conventional scheme checks only the current and the following ones. The CLMD eliminates the bottleneck present in the conventional locking scheme used in the original Calvin paper. We evaluated CLMD with Calvin in experiments. The results showed that the proposed method outperformed SS2PL under high-contention workloads and performed better than Calvin under low and high-contention workloads. The maximum performance improvement observed was approximately 44.4 times using 64 logical cores.