ListDB: Union of Write-Ahead Logs and Persistent SkipLists for Incremental Checkpointing on Persistent Memory


Wonbae Kim, UNIST; Chanyeol Park, Sungkyunkwan University and Naver; Dongui Kim, Sungkyunkwan University and Line; Hyeongjun Park, Sungkyunkwan University; Young-ri Choi, UNIST; Alan Sussman, University of Maryland, College Park; Beomseok Nam, Sungkyunkwan University


Due to the latency difference between DRAM and non-volatile main memory (NVMM) and the limited capacity of DRAM, incoming writes are often stalled in LSM tree-based key-value stores. This paper presents ListDB, a write-optimized key-value store for NVMM to overcome the gap between DRAM and NVMM write latencies and thereby, resolve the write stall problem. The contribution of ListDB consists of three novel techniques: (i) byte-addressable Index-Unified Logging, which incrementally converts write-ahead logs into SkipLists, (ii) Braided SkipList, a simple NUMA-aware SkipList that effectively reduces the NUMA effects of NVMM, and (iii) Zipper Compaction, which moves down the LSM-tree levels without copying key-value objects, but by merging SkipLists in place without blocking concurrent reads. Using the three techniques, ListDB makes background compaction fast enough to resolve the infamous write stall problem and shows 1.6x and 25x higher write throughputs than PACTree and Intel Pmem-RocksDB, respectively.

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@inproceedings {280850,
author = {Wonbae Kim and Chanyeol Park and Dongui Kim and Hyeongjun Park and Young-ri Choi and Alan Sussman and Beomseok Nam},
title = {{ListDB}: Union of {Write-Ahead} Logs and Persistent {SkipLists} for Incremental Checkpointing on Persistent Memory},
booktitle = {16th USENIX Symposium on Operating Systems Design and Implementation (OSDI 22)},
year = {2022},
isbn = {978-1-939133-28-1},
address = {Carlsbad, CA},
pages = {161--177},
url = {},
publisher = {USENIX Association},
month = jul

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