{"title":"Self-service data protection for stateful containers","authors":"Umesh Deshpande, Nick Linck, S. Seshadri","doi":"10.1145/3465332.3470876","DOIUrl":"https://doi.org/10.1145/3465332.3470876","url":null,"abstract":"Data protection in containerized environments poses several challenges arising from the need for self-service and the resulting churn in the environment. We present a self-managing backup system for containerized frameworks designed to work for users with little knowledge of the underlying infrastructure. Our system presents users with an interface which allows them to interact with data protection service in the same way used for managing their applications. Additionally, we present a backup scheduler to honor user expressed data protection guarantees while reacting to resource fluctuations on the underlying shared infrastructure. We demonstrate the effectiveness of our system with thousands of request having different data protection guarantees in an environment with various bandwidth and IO patterns.","PeriodicalId":281760,"journal":{"name":"Proceedings of the 13th ACM Workshop on Hot Topics in Storage and File Systems","volume":"101 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115033856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"How the common retention acceleration method of 3D NAND flash memory goes wrong?","authors":"Qiao Li, Min Ye, Tei-Wei Kuo, C. Xue","doi":"10.1145/3465332.3470877","DOIUrl":"https://doi.org/10.1145/3465332.3470877","url":null,"abstract":"The reliability of solid-state drives (SSDs) has become increasingly important as SSDs are now widely applied in data centers. Retention error is a major source of impact on the reliability of SSDs. Even though the common practice in understanding the retention errors of an SSD is done by high-temperature baking processes, their characterization accuracy is not yet rigidly reviewed. In this paper, we first present how the common retention acceleration method goes wrong. Through a one-year study of 3D flash error behaviors, we found that the retention errors through baking with high temperatures have very different characteristics from the real long-retention errors. These differences come from the inherent structure and the materials of 3D NAND flash. Several findings regarding the retention errors characterized through baking are presented, followed by the analysis of the error behaviors. Finally, the retention errors of one year on 3D flash memory are provided with real data.","PeriodicalId":281760,"journal":{"name":"Proceedings of the 13th ACM Workshop on Hot Topics in Storage and File Systems","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128347889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Libpubl","authors":"Jaewon Jung, Jungsik Choi, Hwansoo Han","doi":"10.1145/3465332.3470874","DOIUrl":"https://doi.org/10.1145/3465332.3470874","url":null,"abstract":"With recent advancement in NVM technologies, non-volatile main memory(NVMM) has been highlighted as promising systems for large scale data centers. By utilizing memory-mapped IO, researchers have attempted to provide fast IOs without kernel mode switches and complex kernel IO layers. Even though they improve the performance by taking advantage of NVMM characteristics, memory-mapped IOs still require additional user-level logging techniques to guarantee write atomicity and file system integrity. We propose a user-level library file system, Libpubl, which is designed to minimize the write amplification overhead of traditional logging by exploiting persistent user buffers as logs. Libpubl ensures atomic updates of data and improves the performance and the scalability. Compared to the state-of-the-art NVM file systems, Libpubl increases the performance by 50~120% in Fio benchmark.","PeriodicalId":281760,"journal":{"name":"Proceedings of the 13th ACM Workshop on Hot Topics in Storage and File Systems","volume":"457 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127610796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Romain Vaillant, Dimitrios Vasilas, M. Shapiro, T. Nguyen
{"title":"CRDTs for truly concurrent file systems","authors":"Romain Vaillant, Dimitrios Vasilas, M. Shapiro, T. Nguyen","doi":"10.1145/3465332.3470872","DOIUrl":"https://doi.org/10.1145/3465332.3470872","url":null,"abstract":"Building scalable and highly available geo-replicated file systems is hard. These systems need to resolve conflicts that emerge in concurrent operations in a way that maintains file system invariants, is meaningful to the user, and does not depart from the traditional file system interface. Conflict resolution in existing systems often leads to unexpected or inconsistent results. This paper introduces ElmerFS, a geo-replicated, truly concurrent file system designed with the aim of addressing these challenges. ElmerFS is based on two key ideas: (1) the use of Conflict-Free Replicated Data Types (CRDTs) for representing file system structures, which ensures that replicas converge to a correct state, and (2) conflict resolution rules, which are determined by the choice of CRDT types and their composition, are designed with the principle of being intuitive to the user. We argue that if the state of the file system after resolving a conflict conveys to the user the resolved conflict in an intuitive way, the user can complement or reverse it using traditional file system operations. We discuss the challenges in the design of geo-replicated weakly consistent file systems, and present the design of ElmerFS.","PeriodicalId":281760,"journal":{"name":"Proceedings of the 13th ACM Workshop on Hot Topics in Storage and File Systems","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121091265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Automatic I/O stream management based on file characteristics","authors":"Yuqi Zhang, Ni Xue, Yangxu Zhou","doi":"10.1145/3465332.3470879","DOIUrl":"https://doi.org/10.1145/3465332.3470879","url":null,"abstract":"Data fragmentation exists widely in SSD NAND flash, which greatly increases garbage collection overhead. Dividing data of different lifetimes into different I/O streams can effectively solve the problem of data fragmentation. Therefore, the management of I/O streams is the key to reduce data fragmentation and thereby improve the lifetime and performance of SSD. In this paper, we propose FileStream, a file-based automatic stream management scheme with machine learning, which can be directly applied to multiple workloads. We find that file characteristics are effective in distinguishing data lifetimes, and thus FileStream divides data into different I/O streams based on the file characteristics. The results of six benchmarks on real SSD show that FileStream reduces the write amplification factor by 34.5% and 21.6% on average, compared to the baseline and two advanced automatic stream management methods, respectively.","PeriodicalId":281760,"journal":{"name":"Proceedings of the 13th ACM Workshop on Hot Topics in Storage and File Systems","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134061807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Omer S. Sella, Amir Apelbaum, T. Heinis, Jasmine Quah, A. Moore
{"title":"DNA archival storage, a bottom up approach","authors":"Omer S. Sella, Amir Apelbaum, T. Heinis, Jasmine Quah, A. Moore","doi":"10.1145/3465332.3470880","DOIUrl":"https://doi.org/10.1145/3465332.3470880","url":null,"abstract":"DNA is an attractive medium for storage of digital data in the cloud, owing to a form factor several orders of magnitude smaller than any other. Key to storing binary data in synthetic in DNA is the translation between the binary representation of digital data to the quaternary domain of DNA. This translation must adhere to constraints imposed by the synthesis and sequencing processes used to write and read respectively. A technological advance in either process changes the constraints and renders current encoding schemes obsolete. In this paper we present a recipe for taking constraints and producing an appropriate encoding scheme. Such a mechanism allows moving the encoding in lockstep with the technological advances in the underlying processes. We further show a method to understand trade-offs in constraints for a given overhead of bits needed to meet such constraints.","PeriodicalId":281760,"journal":{"name":"Proceedings of the 13th ACM Workshop on Hot Topics in Storage and File Systems","volume":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115812464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Enabling near-data processing in distributed object storage systems","authors":"I. Adams, Neha Agrawal, M. Mesnier","doi":"10.1145/3465332.3470881","DOIUrl":"https://doi.org/10.1145/3465332.3470881","url":null,"abstract":"Most general-purpose distributed storage systems are not designed with near data processing (NDP) in mind. They do not respect semantic data boundaries when writing data, for example splitting a record across servers. This reduces NDP effectiveness by requiring data collation before computation. While semantic data awareness and NDP functions can be retroactively added to existing distributed storage, it is often complex and difficult to accomplish in practice. We propose sharing storage system layout information with data writers so they can adjust data layouts to prevent data alignment issues regardless of the underlying architectures. By doing so, we can simplify NDP implementation by reducing the need for data reassembly, and reduce the need for complex storage system or application extensions. We demonstrate a hinting mechanism on both HDFS with computational block storage and an erasure coded MinIO deployment, reducing data movement by up to 99% when querying CSV data with NDP co-located with the stored data. This was accomplished purely with client side data alignment, no modifications to the server side write paths, and no inter-node collation of data.","PeriodicalId":281760,"journal":{"name":"Proceedings of the 13th ACM Workshop on Hot Topics in Storage and File Systems","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127783172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. Akgun, A. S. Aydin, Aadil Shaikh, L. Velikov, E. Zadok
{"title":"A Machine Learning Framework to Improve Storage System Performance","authors":"I. Akgun, A. S. Aydin, Aadil Shaikh, L. Velikov, E. Zadok","doi":"10.1145/3465332.3470875","DOIUrl":"https://doi.org/10.1145/3465332.3470875","url":null,"abstract":"Storage systems and their OS components are designed to accommodate a wide variety of applications and dynamic workloads. Storage components inside the OS contain various heuristic algorithms to provide high performance and adaptability for different workloads. These heuristics may be tunable via parameters, and some system calls allow users to optimize their system performance. These parameters are often predetermined based on experiments with limited applications and hardware. Thus, storage systems often run with these predetermined and possibly suboptimal values. Tuning these parameters manually is impractical: one needs an adaptive, intelligent system to handle dynamic and complex workloads. Machine learning (ML) techniques are capable of recognizing patterns, abstracting them, and making predictions on new data. ML can be a key component to optimize and adapt storage systems. In this position paper, we propose KML, an ML framework for storage systems. We implemented a prototype and demonstrated its capabilities on the well-known problem of tuning optimal readahead values. Our results show that KML has a small memory footprint, introduces negligible overhead, and yet enhances throughput by as much as 2.3x.","PeriodicalId":281760,"journal":{"name":"Proceedings of the 13th ACM Workshop on Hot Topics in Storage and File Systems","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131467187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Isolating namespace and performance in key-value SSDs for multi-tenant environments","authors":"Donghyun Min, Youngjae Kim","doi":"10.1145/3465332.3470883","DOIUrl":"https://doi.org/10.1145/3465332.3470883","url":null,"abstract":"Key-value SSDs (KVSSDs) implement the storage engine of a key-value store such as log-structured merge-tree (LSM-tree) inside the SSD. However, recent LSM-tree based KVSSDs cannot be used directly in a multi-tenant environment. LSMtree-based KVSSDs are not designed with isolation in mind in terms of namespaces and performance, leading to incorrect data access between concurrent users and poor read performance. In this paper, we propose Iso-KVSSD, a LSM-tree based KVSSD for multi-tenancy by supporting namespace and performance isolation. The Iso-KVSSD performs access control based on the user's namespace and constructs per-namespace dedicated LSM-trees for users. We implement the Iso-KVSSD on Cosmos+ OpenSSD in a Linux environment and evaluate performance with Put() and Get() workloads by varying the number of tenants. Our extensive evaluation results showed that Iso-KVSSD has negligible write performance overhead and an average 2.9 times higher read throughput than a baseline that manages one global shared LSM tree between users.","PeriodicalId":281760,"journal":{"name":"Proceedings of the 13th ACM Workshop on Hot Topics in Storage and File Systems","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123733248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"SentiLog","authors":"Di Zhang, Dong Dai, Runzhou Han, Mai Zheng","doi":"10.1145/3465332.3470873","DOIUrl":"https://doi.org/10.1145/3465332.3470873","url":null,"abstract":"As core components of High-performance computing (HPC) platforms, parallel file systems (PFSes) grow quickly in scale and complexity, hence are subject to various failures and anomalies. Identifying their anomalies in runtime is critically helpful for HPC operators and administrators. Analyzing the runtime logs to detect the anomalies of large-scale systems has been proven effective in many recent studies. However, applying them to parallel file systems logs faces significant challenges due to the large volume and irregularity of PFSes logs. This study proposes SentiLog, a new approach to analyzing PFSes system logs for detecting anomalies. Unlike existing solutions, SentiLog works by training a general sentimental, natural language model based on the logging-relevant source code collected from a set of PFSes. In this way, SentiLog learns information embedded by developers from the source code. Our preliminary results show SentiLog is able to accurately predict anomalies and performs better than state-of-the-art log analysis solutions on two representative PFSes (Lustre and BeeGFS). This preliminary study shows sentiment analysis could be a promising method to analyze complex and irregular system logs.","PeriodicalId":281760,"journal":{"name":"Proceedings of the 13th ACM Workshop on Hot Topics in Storage and File Systems","volume":"13 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116835946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}