Nowadays the 2-Phase-Locking (2PL) concurrency control algorithm still plays a core rule in the construction of trans-actional systems (e.g. database systems and transactional memories). Hence, any technique allowing accurate analysis and prediction of the performance of 2PL based systems can be of wide interest and applicability. In this article we present an accurate analytical model of 2PL concurrency control, which overcomes several limitations of preexisting analytical results. In particular our model captures relevant features of realistic data access patterns, by taking into account access distributions that depend on transactions' execution phases. Also, our model provides significantly more accurate performance predictions in heavy contention scenarios, where the number of transactions enqueued due to conflicting lock requests is expected to be non-minimal. The accuracy of our model has been verified against simulation results based on both synthetic data access patterns and patterns derived from the TPC-C benchmark.
展开▼
