ICCG:low-cost and efficient consistency with adaptive synchronization for metadata replication  

作　　者：Chenhao ZHANG Liang WANG Jing SHANG Zhiwen XIAO Limin XIAO Meng HAN Bing WEI Runnan SHEN Jinquan WANG 

机构地区：[1]State Key Laboratory of Software Development Environment,Beihang University,Beijing 100191,China [2]School of Computer Science and Engineering,Beihang University,Beijing 100191,China [3]School of Cyberspace Security,Hainan University,Haikou 570228,China [4]China Mobile Information Technology Center,Beijing 100033,China

出　　处：《Frontiers of Computer Science》2025年第1期53-70,共18页计算机科学前沿(英文版)

基　　金：supported in part by the National Key R&D Program of China under Grant 2022ZD0117602;in part by the National Natural Science Foundation of China under Grants 62272026 and 62104014;in part by the fund of the State Key Laboratory of Software Development Environment under Grant SKLSDE-2022ZX-07;in part by the Beihang Frontier Interdisciplinary Fund under Grant YWF-23-Q-1015;in part by the Beijing Advanced Innovation Center for Future Blockchain and Privacy Computing;and in part by the Iluvatar CoreX Semiconductor Co.,Ltd.

摘　　要：The rapid growth in the storage scale of wide-area distributed file systems (DFS) calls for fast and scalable metadata management. Metadata replication is the widely used technique for improving the performance and scalability of metadata management. Because of the POSIX requirement of file systems, many existing metadata management techniques utilize a costly design for the sake of metadata consistency, leading to unacceptable performance overhead. We propose a new metadata consistency maintenance method (ICCG), which includes an incremental consistency guaranteed directory tree synchronization (ICGDT) and a causal consistency guaranteed replica index synchronization (CCGRI), to ensure system performance without sacrificing metadata consistency. ICGDT uses a flexible consistency scheme based on the state of files and directories maintained through the conflict state tree to provide an incremental consistency for metadata, which satisfies both metadata consistency and performance requirements. CCGRI ensures low latency and consistent access to data by establishing a causal consistency for replica indexes through multi-version extent trees and logical time. Experimental results demonstrate the effectiveness of our methods. Compared with the strong consistency policies widely used in modern DFSes, our methods significantly improve the system performance. For example, in file creation, ICCG can improve the performance of directory tree operations by at least 36.4 times.

关 键 词：metadata management metadata replication CONSISTENCY directory tree replica index 

分 类 号：G25[文化科学—图书馆学]