A Novel Disk Queue to Reduce Disk I/O of Messaging System

摘要

High reliability is the primary requirement for messaging system. Messaging system always utilizes disk queue to temporarily store waiting message. This paper analyzes by experiments and points out that disk queue I/O is the primary performance bottleneck in messaging system. To efficiently reduce disk I/O of messaging system, we propose a novel disk queue called SmartQ which utilizes pre-assigned continuous disk space to act as disk queue to reduce file manage overhead. Lazy Gathering Write and Sequential Grouping Prefetching polices of the SmartQ not only reduce the number of write and read, but also make full use of the disk bandwidth. Experiment shows that performance of the SmartQ is more than an order of magnitude higher than that of traditional disk queue.