S-Space College of Engineering/Engineering Practice School (공과대학/대학원) Dept. of Computer Science and Engineering (컴퓨터공학부) Theses (Master's Degree_컴퓨터공학부)
Optimization of Distributed Storage on Commodity SSD using NVDIMM
NVDIMM을 상용 SSD와 사용할 때의 분산 스토리지 최적화
- 공과대학 컴퓨터공학부
- Issue Date
- 서울대학교 대학원
- 학위논문 (석사)-- 서울대학교 대학원 공과대학 컴퓨터공학부, 2017. 8. 염헌영.
- As cloud computing has been dominant, people become interested in distributed storage system used in data center. One of the most attractive things is ceph distributed storage. Thats because it has various advantages like high scalability, fault tolerance and rebalancing data objects automatically. Client can communicate the node which has the target data object directly, without extra communication with metadata server. Ceph distributed storage is said to be petabyte scalable for these reasons. In addition, the replication functionality of ceph ensures high availability, fault tolerance and no single point of failure. Thats why ceph has been selected as our target system.
Even if ceph has various advantages like scalability, it has not been designed for the usage of NVDIMM with commodity SSD. So, the research focuses on how the ceph distributed storage has to be optimized for NVDIMM with commodity SSD. First, how the internal implementation of ceph has to be optimized for using NVDIMM as write buffer will be explained. This optimization has been implemented by making worker threads issue I/O request to NVDIMM and reply to client. This optimization improves the performance of write request. Second, how the mixed workload, which contains read and write request, should be dealt with will be explained. The above-mentioned optimization for write request cant improve the performance of mixed workload. The reason is that read requests can race with flush command. To remove the race, separation of read request and flush command should be used.