Digital Library[ Search Result ]
Performance Improvement of LSM-tree Using Partial Flushing of MemTable
Hyeongjun Jeon, Hera Koo, Sungho Moon, Beomseok Nam
http://doi.org/10.5626/JOK.2023.50.1.87
Key-Value store, which is one of the NoSQL databases, uses Log-Structured Merge Tree(LSM Tree) as its index data structure. LSM Tree normally has good writing performance, but write amplification and write stall as chronic problems in LSM Tree have impeded the write performance of LSM Tree. In this paper, we introduce Extended MemTable which is an extended version of the current LSM Tree’s MemTable considering that recent datacenter’s main memory space is increasing. Extended Memtable uses partition which is divided by key ranges. It does the flush operation in the manner that the compaction operation can be operated effectively. It can increase the write throughput by up to 2 x and the read throughput by up to 4 x while reducing write amplification by up to 3.7 x compared to the original RocksDB by significantly reducing write amplification and write stall problems.
LSM Tree Compaction Offloading Using NVMe-oF
Sungho Moon, Hera Koo, Hyeongjun Jeon, Beomseok Nam
http://doi.org/10.5626/JOK.2022.49.7.569
NVMe-over-Fabrics (NVMe-oF) is drawing attraction in the industry as an alternative to disaggregated storage by providing fast access to remote NVMe SSDs through NVMe commands. In this paper, we propose RocksDB-oF, an LSM-Tree-based key-value store optimized for disaggregated storage using NVMe-oF. RocksDB-oF alleviated the Write Stall problem by offloading compaction from the computing node onto the storage node in consideration of the characteristics of NVMe-oF. In addition, a file system that uses Storage Performance Development Kit (SPDK) effectively solves the file system consistency problem of two nodes accessing the same NVMe SSD at the same time. Experimentally, in a disaggregated storage environment with NVMe-oF, RocksDB-oF showed higher write throughput than legacy RocksDB.
Optimization of Load Balancing on LSM-Tree based Distributed Key-Value Store using NVMe-oF
Hera Koo, Sungho Moon, Hyeongjun Jeon, Beomsuk Nam
http://doi.org/10.5626/JOK.2022.49.7.561
One of the challenges of distributed key-value databases which distribute and store data according to the key is load balancing. In this paper, we propose MongoRocks-oF, a redesigned MongoRocks, which is a MongoDB distributed database with RocksDB engine, an LSM-tree based key-value store, for optimizing load balancing with NVMe-over-Fabrics. MongoRocks-oF distributes data evenly in a round-robin fashion using NVMe-over-Fabrics that enables computing nodes to share multiple NVMe SSDs in remote storage through all-to-all connections, and fully utilizes storage resources. Based on this design, the proposed MongoRocks-oF improve load balance of legacy MongoRocks and shows better performance on write operations compared to MongoRocks.
Search
Journal of KIISE
- ISSN : 2383-630X(Print)
- ISSN : 2383-6296(Electronic)
- KCI Accredited Journal
Editorial Office
- Tel. +82-2-588-9240
- Fax. +82-2-521-1352
- E-mail. chwoo@kiise.or.kr