AdaCache: A Disaggregated Cache System with Adaptive Block Size for Cloud Block Storage
AdaCache: A Disaggregated Cache System with Adaptive Block Size for Cloud Block Storage
复制标题
DOI：
10.1109/cloud60044.2023.00048
复制
发表时间：
2023-06
期刊：
影响因子：
--
通讯作者：
Qirui Yang;Runyu Jin;Ni Fan;D. Inupakutika;Bridget Davis;Mingde Zhao
中科院分区：
文献类型：
--
作者：
Qirui Yang;Runyu Jin;Ni Fan;D. Inupakutika;Bridget Davis;Mingde Zhao
NVME SSD缓存在求解云块存储的I/O瓶颈方面表现出了令人印象深刻的功能，并在公共，私人和混合云环境中提高了应用程序性能。但是，传统的寄主缓存解决方案有几个严重的局限性。首先，不能在主机上共享缓存，从而导致低缓存利用率。其次，常用的固定尺寸的缓存块分配机制无法提供良好的缓存性能，并提供低内存开销的较低的内存，用于不同的I/O模式不同的云工作负载。本文介绍了Adacache，这是一种新颖的用户空间分解缓存系统，该系统利用自适应缓存块分配用于云块存储。首先，Adacache提出了一种创新的自适应缓存块分配方案，该方案根据请求大小分配缓存块，以达到良好的缓存性能和低内存开销。其次，Adacache提出了一个基于组的高速缓存组织，该组织将缓存块存储到组中，以解决可变大小的高速缓存块带来的碎片问题。第三，Adacache设计了两级缓存替换策略，该策略替换了单个块和组中的高速缓存块以提高命中率。现实世界痕迹的实验结果表明，与传统的固定尺寸的缓存系统相比，ADACACHE可以大大提高I/O性能，并减少由于记忆使用率较低而引起的存储访问。
NVMe SSD caching has demonstrated impressive capabilities in solving cloud block storage's I/O bottleneck and enhancing application performance in public, private, and hybrid cloud environments. However, traditional host-side caching solutions have several serious limitations. First, the cache cannot be shared across hosts, leading to low cache utilization. Second, the commonly-used fix-sized cache block allocation mechanism is unable to provide good cache performance with low memory overhead for diverse cloud workloads with vastly different I/O patterns. This paper presents AdaCache, a novel userspace disaggregated cache system that utilizes adaptive cache block allocation for cloud block storage. First, AdaCache proposes an innovative adaptive cache block allocation scheme that allocates cache blocks based on the request size to achieve both good cache performance and low memory overhead. Second, AdaCache proposes a group-based cache organization that stores cache blocks into groups to solve the fragmentation problem brought by variable-sized cache blocks. Third, AdaCache designs a two-level cache replacement policy that replaces cache blocks in both single blocks and groups to improve the hit ratio. Experimental results with real-world traces show that AdaCache can substantially improve I/O performance and reduce storage access caused by cache miss with a much lower memory usage compared to traditional fix-sized cache systems.