TY  - JOUR
T1  - Improving Compaction in LSM Tree by Applying Simple Copy to Key-Value Separated LSM-Tree
AU  - Lee, Chihyun 
AU  - Moon, Sungho 
AU  - Chae, Sangeun 
AU  - Nam, Beomsuk 
JO  - Journal of KIISE, JOK
PY  - 2025
DA  - 2025/1/14
DO  - 10.5626/JOK.2025.52.11.1002
KW  - LSM-Tree
KW  - Key-Value Separated LSM-Tree
KW  - compaction
KW  - write stall
KW  - ZNS-SSD
AB  - The LSM-Tree(Log-Structured Merge-Tree) is a widely adopted indexing structure known for its superior write performance across various application domains. However, a persistent performance bottleneck arises from write stalls caused by the relatively slow compaction process compared to the high rate of incoming data. Numerous studies, such as Key-Value Separated LSM-Tree and ZenFS, have been proposed to address this issue. In this paper, we introduce a method that replaces the LSM-Tree’s underlying file system with a ZNS-SSD (Zoned Namespace SSD) and leverages the simple copy to separate keys and values. This approach minimizes value-reading I/O from the disk while avoiding side effects like garbage collection, thereby accelerating the compaction process. We apply this technique to L0–L1 compaction and L0 compaction, effectively mitigating the write stall problem.