FOXpath - an expression language for selecting files and folders

Author(s):  
Hans-Jürgen Rennau

A new expression language (FOXpath, short for folder XPath) enables XPath-like addressing of files and folders in a file system. The first version of the language is a modified copy of XPath 3.0, with node navigation removed and file system navigation added. The language is based on the data model XDM 3.0, without assuming any modifications of the model. In a second step, the language was merged back into XPath 3.0, resulting in FOXpath 3.0, which is a superset of XPath 3.0. The new expression language supports node navigation, file system navigation and a free combination of both functionalities within a single path expression. A reference implementation is described, and the possibility of extending the new functionality beyond file systems is discussed.

2015 ◽  
Vol 713-715 ◽  
pp. 2418-2422
Author(s):  
Lei Rao ◽  
Fan De Yang ◽  
Xin Ming Li ◽  
Dong Liu

Data management has experienced three stages: labor management, file systems, and database systems. In this paper, manage equipment data using a combination of HDFS file system and HBase database: the principles of HBase data management is studied; equipment data’s reading and writing processes is established; data model of equipment database is designed based on HBase.


2012 ◽  
Vol 263-266 ◽  
pp. 1979-1986
Author(s):  
Qiang Li ◽  
Li Gu Zhu ◽  
Sai Feng Zeng

Updates discovery is the key problem of data synchronization; it has been used to generate updates operations. The traditional algorithms ignore the modify semanteme, cause the updates operations increased. A new file updating discovery algorithm that supports semantic synchronization is proposed in this paper. The algorithm takes advantage of semantic info, which preserved in file system journal, to accurately recognize users originally modify intents. We take the NTFS file system as an example to realize and test the new algorithm. By comparison, the algorithm effectively reduces synchronization requests. Experiments show that, the algorithm cans timely respond to users’ modification and support massive file changes that occurred in short time. The algorithm is designed based on the basic features of file system journal, and can be applied to other file systems.


2021 ◽  
Vol 17 (3) ◽  
pp. 1-25
Author(s):  
Bohong Zhu ◽  
Youmin Chen ◽  
Qing Wang ◽  
Youyou Lu ◽  
Jiwu Shu

Non-volatile memory and remote direct memory access (RDMA) provide extremely high performance in storage and network hardware. However, existing distributed file systems strictly isolate file system and network layers, and the heavy layered software designs leave high-speed hardware under-exploited. In this article, we propose an RDMA-enabled distributed persistent memory file system, Octopus + , to redesign file system internal mechanisms by closely coupling non-volatile memory and RDMA features. For data operations, Octopus + directly accesses a shared persistent memory pool to reduce memory copying overhead, and actively fetches and pushes data all in clients to rebalance the load between the server and network. For metadata operations, Octopus + introduces self-identified remote procedure calls for immediate notification between file systems and networking, and an efficient distributed transaction mechanism for consistency. Octopus + is enabled with replication feature to provide better availability. Evaluations on Intel Optane DC Persistent Memory Modules show that Octopus + achieves nearly the raw bandwidth for large I/Os and orders of magnitude better performance than existing distributed file systems.


2019 ◽  
Vol 3 (9) ◽  
pp. 283-289
Author(s):  
Shuchi Sukul ◽  
Goldy Rathee ◽  
Parimal Anand ◽  
Sakshi Kataria ◽  
Pratibha Taneja

OBJECTIVES: The present research was conducted to assess incidences of root microcracks caused by hand and rotary file system at different lengths MATERIAL AND METHODS: This in-vitro study was undertaken to assess incidence of root microcracks caused by hand and rotary file system at different lengths In total, 100 the mandibular premolar with straight roots determined with intact, fully formed apices were taken. Samples were randomly distributed into 5 groups based on the file system used: a) Group A: Control, b) Group B: Reciproc, c) Group C: WaveOne, d) Group D: One Shape and e) Group E: ProTaper. Pearson Chi-square test was used to determine the differences between groups. The dentinal defects were expressed as percentage of samples with microcracks in each group. Level of statistical significance was set at p-value less than 0.05. RESULTS: The chi square test was used to compare the Distribution of the number of teeth in which cracks were observed on the horizontal sections. It was found to be significant with group ProTaper showing maximum cracks at 3,6,9 mm level as compared to other file systemCONCLUSION: Nickel-titanium instruments causes cracks on the apical root surface or in the root canal wall. ProTaper causes maximum dentinal cracks as compared to other file systems


Author(s):  
Armando Fandango ◽  
William Rivera

Scientific Big Data being gathered at exascale needs to be stored, retrieved and manipulated. The storage stack for scientific Big Data includes a file system at the system level for physical organization of the data, and a file format and input/output (I/O) system at the application level for logical organization of the data; both of them of high-performance variety for exascale. The high-performance file system is designed with concurrent access, high-speed transmission and fault tolerance characteristics. High-performance file formats and I/O are designed to allow parallel and distributed applications with easy and fast access to Big Data. These specialized file formats make it easier to store and access Big Data for scientific visualization and predictive analytics. This chapter provides a brief review of the characteristics of high-performance file systems such as Lustre and GPFS, and high-performance file formats such as HDF5, NetCDF, MPI-IO, and HDFS.


Author(s):  
Mian-Guan Lim ◽  
Sining Wu ◽  
Tomasz Simon ◽  
Md Rashid ◽  
Na Helian

On-demand cloud applications like online email accounts and online virtual disk space are becoming widely available in various forms. In cloud applications, one can see the importance of underlying resources, such as disk space, that is available to the end-user but not easily accessible. In the authors’ study, a modern file system developed in linux is proposed, which enables consuming of cloud applications and making the underlying disk space resource available to the end-user. This system is developed as a web service to support cross operation system support. A free online mail account was used to demonstrate this solution, and an IMAP protocol to communicate with remote data spaces was used so that this method can mount onto any email system that supports IMAP. The authors’ definition of infinite storage as the user is able to mount file systems as a single logical drive.


2012 ◽  
Vol 6 (2) ◽  
pp. 53-63 ◽  
Author(s):  
U. S. Rawat ◽  
Shishir Kumar

Proposed is a secure and efficient approach for designing and implementing an enterprise-class cryptographic file system for Linux (ECFS) in kernel-space. It uses stackable file system interface to introduce a layer for encrypting files using symmetric keys, and public-key cryptography for user authentication and file sharing, like other existing enterprise-class cryptographic file systems. It differs itself from existing systems by including all public-key cryptographic operations and public-key infrastructure (PKI) support in kernel-space that protects it from attacks that may take place with a user-space PKI support. It has a narrower domain of trust than existing systems. It uses XTS mode of AES algorithm for file encryption for providing better protection and performance. It also uses kernel-keyring service for improving performance. It stores the cryptographic metadata in file’s access control list (ACL) as extended attributes to ease the task of file sharing. A secure protocol has also been designed and implemented to guard against various possible attacks, when its files are accessed remotely over an untrusted network.


2019 ◽  
Vol 9 (2) ◽  
pp. 296 ◽  
Author(s):  
Steven J. H. Shiau ◽  
Yu-Chiang Huang ◽  
Ching-Hsuan Yen ◽  
Yu-Chin Tsai ◽  
Chen-Kai Sun ◽  
...  

: The BitTorrent (BT) is a peer-to-peer (P2P) file sharing protocol that was developed approximately 20 years ago, is becoming increasingly popular, and has been widely accepted. The BT-based mass deployment system can be used to improve performance and scalability that cannot be achieved by the unicasting, broadcasting, and multicasting protocols. However, when the BT-based system is applied in massive deployments, a major issue related to insufficient temporary storage space to store the whole system image before deploying needs to be resolved. Such problems arose because the system is deployed to the disk space, meaning that it cannot be used for temporary storage. Therefore, a novel BT-based solution that can remove the limitations caused by the insufficient temporary storage issue is proposed. The BT-based mass deployment system was designed by using the file system blocks transferring (FSBT) mechanism. The receiver of the FSBT mechanism can obtain the blocks of the file system from other peers. Then, those blocks will be written directly to raw disks or partitions. The sender of the FSBT mechanism can read the blocks of file systems directly from raw disks or partitions. Then, the blocks can be sent to other peers. This approach solves the insufficient temporary storage issue. The novel BT-based mass deployment system was tested and verified for the configuration consisting of at most 32 personal computers (PCs). To demonstrate the achievable performance of the novel BT-based system, comparisons were made between the novel program and the traditional multicast solutions, as well as other solutions for mass deployment. The proposed BT solution can be much faster than the multicast solution when deploying 11 machines or more. The experimental results demonstrated the feasibility and superior performance of the proposed system. Furthermore, performance comparisons of the proposed BT-based mass deployment system versus other solutions demonstrated the feasibility and efficiency of the proposed solution. In the future, the BT parameters can be further optimized, and the simultaneous read and write features can be implemented to improve the deployment performance. In addition, the BT-based mass deployment system can serve as the basis for the development of other mass deployment systems.


2020 ◽  
Vol 14 (03) ◽  
pp. 393-396
Author(s):  
Benjamin Mahmoodi ◽  
Adriano Azaripour ◽  
Kawe Sagheb ◽  
Keyvan Sagheb ◽  
Brita Willershausen ◽  
...  

Abstract Objectives Reciprocating endodontic one-file systems are a comparatively new method for root canal shaping. Even though the mechanical properties are comparable to modern rotating mechanical systems, data about subjective assessment and application quality are scarce. This study evaluates the reciprocating one-file system in undergraduate education. Materials and Methods A total of 42 undergraduate students without experience regarding reciprocating file systems filled in a questionnaire in four different points in time (t 1–t 4) anonymously. The questionnaire was based on a numerical rating scale ranging from 0 to 10. Statistical Analysis A least significant difference post-hoc analysis comparing the group average values was performed. The adjusted level of significance was p < 0.004 after Bonferroni correction. Results All rating scores increased after the first theoretical instruction. After the first practical training in artificial root canals in resin blocks and extracted teeth (t 2), the estimation of “time efficiency” (p = 0.002), “handling” (p < 0.001), and “overall impression” (p < 0.001) improved significantly. The “overall impression” remained constant and showed no significant changes after the first practical training. Conclusions Reciprocating systems seem to show a good acceptance among first time users. Initial concerns about “work safety” decrease during every step of the educational process. Reciprocating one-file systems are a safe and well-accepted method in undergraduate teaching.


Author(s):  
Qiang Zou ◽  
Yujuan Tan

As one of the workload characteristics, the anomaly behaviors in real workload have been recognized as a critical requirement for file system design. In this paper, a set of traces collected from typically realistic file system have been analyzed. The correlation study of I/O request inter-arrival times shows that it is necessary to examine the self-similarity in file system workload. Then the phenomenon of self-similarity which had been initially observed in network and disk I/O workload has also been visually and statistically observed in file system workload. In addition, we implement an I/O series generator in which the inputs are the measured properties of the available trace data. Experimental results show that this model can accurately emulate the complex access arrival behaviors of real file systems, particularly the heavy-tail characteristics.


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