Extensible buffer cache management for heterogeneous environment

Abstract

In traditional buffer cache management scheme such as LRU, useful files characteristics cannot be exploited since it manages disk data at system-wide block-level. Application/File-level Characterization (AFC) Scheme is the first file-level characterization of block reference but it is also generalized management like LRU; AFC is improved only when treating sequential and looping references, that is, not adaptive on various workload. Modern computer systems run various applications with various storage devices. And this heterogeneity degrades performance with traditional buffer cache since it assumes only zipf-like workload with hard disk. In this paper, we design and implement EBM, extensible buffer cache management scheme for heterogeneous environment to make buffer cache more adaptive to modern computer system. EBM is composed of several buffer caches managed by their own buffer cache management algorithm, coordinator that control the buffer caches and rule manager that detects and allocates data as being configured by administrator. EBM supports many information and conditions to make the scheme more flexible and extensible. And it uses trace-based coordination to control buffer caches in fair way. Performance evaluation of EBM implemented on linux kernel 2.6.18.1 shows that EBM reduces total execution time of I/O intensive workload about 50% by reducing the number of I/O requests dramatically.