Paper Info
Title
Azor: Using Two-Level Block Selection to Improve SSD-Based I/O Caches
Abstract
Flash-based solid state drives (SSDs) exhibit potential for solving I/O bottlenecks by offering superior performance over hard disks for several workloads. In this work we design Azor, an SSD-based I/O cache that operates at the block-level and is transparent to existing applications, such as databases. Our design provides various choices for associativity, write policies and cache line size, while maintaining a high degree of I/O concurrency. Our main contribution is that we explore differentiation of HDD blocks according to their expected importance on system performance. We design and analyze a two-level block selection scheme that dynamically differentiates HDD blocks, and selectively places them in the limited space of the SSD cache. We implement Azor in the Linux kernel and evaluate its effectiveness experimentally using a server-type platform and large problem sizes with three I/O intensive workloads: TPC-H, SPECsfs 2008, and Hammerora. Our results show that as the cache size increases, Azor enhances I/O performance by up to 14.02脳, 1.63脳, and 1.55脳 for each workload respectively. Additionally, our two-level block selection scheme further enhances I/O performance compared to a typical SSD cache by up to 95%, 16%, and 34% for each workload, respectively.
Year
DOI
Venue
2011
10.1109/NAS.2011.50
Networking, Architecture and Storage
Keywords
Field
DocType
two-level block selection,ssd cache,o concurrency,cache size increase,o performance,o bottleneck,cache line size,o cache,two-level block selection scheme,o caches,typical ssd cache,o intensive workloads,benchmark testing,memory management,evaluation,throughput,servers,system performance,databases
CPU cache,Computer science,Concurrency,Cache,Parallel computing,Input/output,Real-time computing,Memory management,Throughput,Operating system,Benchmark (computing),Linux kernel
Conference
ISBN
Citations 
PageRank 
978-0-7695-4509-7
9
0.56
References 
Authors
19
5
Name
Order
Citations
PageRank
Yannis Klonatos11136.56
Thanos Makatos2452.14
Manolis Marazakis313620.29
Michail D. Flouris41319.38
Angelos Bilas559860.49