Performance of Cache Consistency Algorithms

This chapter presents a performance analysis of the three families of cache consistency maintenance algorithms described in Chapter 4, namely, Server-based Two-Phase Locking (S2PL), Optimistic Two-Phase Locking (O2PL), and Callback Locking (CB). Seven algorithms are studied under a range of workloads and system configurations. In addition to measuring the performance of these specific algorithms, the experiments presented here also provide insight into many of the tradeoffs involved in cache maintenance, including: optimism vs. pessimism, detection vs. avoidance, and invalidation vs. propagation. The analysis is performed using the simulation model described in Chapter 3. The parameter settings and workloads that are used in the study are described in the following section. The results are then presented in the two subsequent sections. Performance results for the server-based 2PL and optimistic 2PL algorithms are presented first. The performance of the callback locking algorithms is then studied and compared to the better of the S2PL and O2PL algorithms.