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Research On Hybrid-logging Mechanism In Non-volatile Main Memory File System

Posted on:2019-12-10Degree:MasterType:Thesis
Country:ChinaCandidate:N Q LiuFull Text:PDF
GTID:2428330563492477Subject:Computer system architecture
Abstract/Summary:PDF Full Text Request
Currently file systems based on Non-Volatile Memory become the research hotspots because of the fast development of NVM technologies.Ensuring the consistency of application data is non-trivial in NVM-based persistent memory systems.Existing file systems have their own consistency mechanisms.However,these consistency mechanisms have their own cons,which degrades system performance.Moreover,most file systems only provide mechanism for protecting their own metadata or data from corruption while ignoring the corresponding protection for application data,providing no consistent update protocols for application data.As a result,most applications need to implement their own consistent protocols to achieve failure consistency,leading to disappointing performance on applications.In this thesis,we propose a hybrid logging mechanism based on NVM file system.First,we decouple file system metadata and data and use different logging mechanism for metadata and data according to their different updating features and performance overhead of undo logging and redo logging.Second,we design and implement a Two-Level Index consisting of B-tree and list for redo logging,which can improve the performance of file reading.Third,we implement optimized concurrent checkpointing,which allows asynchronous checkpointing to be performed in parallel with minimum data copies.Finally,we offer a series of easy-to-use transaction-based interfaces for application to call,which can ensure the consistency of application data and eliminate redundant consistency mechanism in application level.Evaluations on Non-Volatile file system which uses hybrid logging mechanism demonstrate that HLM can provide consistency for both metadata and data.Moreover,HLMFS outperforms PMFS and NOVA by up to 63.4% and 76.3%.
Keywords/Search Tags:Non-volatile memory, File system, Log, Consistency
PDF Full Text Request
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