SGPM: A coroutine framework for transaction processing

Abstract

Coroutine is able to increase program concurrency and processor core utilization. However, for adapting the coroutine-to-transaction model, the existing coroutine package has the following disadvantages: (1) Additional scheduler threads incur synchronization overhead when the load between scheduler threads and worker threads is unbalanced. (2) Coroutines are swapped out periodically to prevent deadlocks, which will increase the conflict rate by adding suspended transactions. (3) Supporting only the swap-out function (yield, await, etc.) cannot flexibly control the transaction swap-in time. In this paper, we present SGPM, a coroutine framework for transaction processing. To adapt to the coroutine-to-transaction model, SGPM has the following properties: First, it eliminates scheduler threads and the periodic coroutine switch. Second, it provides a variety of coroutine scheduling strategies to make all types of concurrency control protocols run on SGPM reasonably. We implement eight well-known concurrency control on SGPM and, particularly, we use SGPM to optimize the performance of four wound-wait concurrency control among them, including 2PL, SS2PL, Calvin, and EWV. The experiment result demonstrates that after SGPM optimization 2PL and SS2PL outperform OCC and MVCC, and the throughput of Calvin and EWV is also improved by 1.2x and 1.3x respectively.