Hardware & Software Co-optimization for High Performance / High Functionality SSDs in Data Centers (2014)

Overview

Research on cross-layer optimizations for key value storages targeting to reduce latency variations caused by mixed read and write operations on a flash SSD. Developed a multi-SSD storage engine which employs the capability of performing read-write separation as well as exploiting garbage collection API calls provided by the SSDs (Customized Samsung SSDs). Developed a custom storage engine integrated with Memcached 1.4.17 to demonstrate the effectiveness of tight cross-layer optimizations. Was able to reduce the 99.9999 percentile tail latency of foreground read operations to be under 1ms. Reported the results in ICPADS’14 & BigComp’15 (Best paper awards).

Technology

• Custom I/O stack for multiple SATA 3.0 SSDs
• Custom key value store in user space implemented in C
• User-space storage engine implemented in C
• Engineering samples of “Smart SSDs” with GC control capability from Samsung Electronics

Publications

• Shin et al., “HIOPS-KV: Exploiting multiple flash solid-state drives for key value stores”, ICPADS'14 Workshop
• Shin et al., “Providing QoS through host controlled flash SSD garbage collection and multiple SSDs”, IEEE BigComp'15