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For a Chinook salmon restoration project in the lower Yuba River in California, we designed and deployed a wireless sensor network to monitor river temperatures at micro-habitat scales. The study required that temperatures be measured along a 3 km study reach, across the channel, and into off-channel areas. To capture diel and seasonal fluctuations, sensors were sampled quarter-hourly for the full duration of the six-month juvenile salmon winter residency. This sampling duration required that nodes minimize power-use. We adopted event-based software on MSP430 micro-controllers with 433 MHz radio and minimized the networking duty-cycle. To address link failures, we included network storage. As the network lacked real-time clocks, data were timestamped at the destination. This, coupled with the storage, yielded timestamp inaccuracies, which we re-aligned using a novel algorithm. We collected over six months of temperature data from 35 sensors across seven nodes. Of the packets collected, we identified 21% as being incorrectly timestamped and were able to re-align 41% of these incorrectly timestamped packets. We collected temperature data through major floods, and the network uploaded data until the flood destroyed the sensors. The network met an important need in ecological sampling with ultra-low power (multi-year battery life) and low-throughput.

The threat of radiation exposure is always present in modern world. In recent years, this threat has become even more pronounced due to Russian aggression on Ukrainian territory. Therefore, the need for remote data collection and analysis of radiation background information has become even more important, and research in the field of creating small, low-cost devices that can monitor radiation levels of a certain area in real-time and provide information to local government agencies responsible for the safety of populated areas can be considered relevant. Radiation background level monitoring is essential to ensuring that people are informed of any potential threats to their health. It is proposed to develop a dense network of monitoring stations that can collect and transmit data about background radiation in real time. Measurement results will be processed and stored on a resource that is available to both local authorities and public. The Message Queue Telemetry Transport (MQTT) protocol is used to transmit information, as it is durable, lightweight, and efficient. A hardware and software system for collecting and transmitting radioactivity values has been developed. The system is based on a module with Geiger counter tube, which is used to measure the level of radiation in the area. The module is connected to a microcontroller, which processes the data and transmits it to a central server. To summarize and process the measurement results, the Majordomo broker is used. It is installed on a remotely accessible network storage. In conclusion, the proposed system can ensure the safety of the public, allowing authorities, experts and trained personnel to quickly and efficiently respond to any potential radiation threats, protecting people from radiation exposure.

The threat of radiation exposure is always present in modern world. In recent years, this threat has become even more pronounced due to Russian aggression on Ukrainian territory. Therefore, the need for remote data collection and analysis of radiation background information has become even more important, and research in the field of creating small, low-cost devices that can monitor radiation levels of a certain area in real-time and provide information to local government agencies responsible for the safety of populated areas can be considered relevant. Radiation background level monitoring is essential to ensuring that people are informed of any potential threats to their health. It is proposed to develop a dense network of monitoring stations that can collect and transmit data about background radiation in real time. Measurement results will be processed and stored on a resource that is available to both local authorities and public. The Message Queue Telemetry Transport (MQTT) protocol is used to transmit information, as it is durable, lightweight, and efficient. A hardware and software system for collecting and transmitting radioactivity values has been developed. The system is based on a module with Geiger counter tube, which is used to measure the level of radiation in the area. The module is connected to a microcontroller, which processes the data and transmits it to a central server. To summarize and process the measurement results, the Majordomo broker is used. It is installed on a remotely accessible network storage. In conclusion, the proposed system can ensure the safety of the public, allowing authorities, experts and trained personnel to quickly and efficiently respond to any potential radiation threats, protecting people from radiation exposure. [ABSTRACT FROM AUTHOR]

As part of a restoration project designed to enhance Chinook salmon populations in the lower Yuba River, we sought to characterize river temperatures at micro-habitats scales relevant to juveniles. Given that temperatures vary more across the channel than they do longitudinally, temperature had to be assayed both along the length of a study reach as well as across the channel. These temperatures needed to be measured at least hourly in order to capture the totality of the diel fluctuations. It was necessary to sample for the full duration of juvenile residence in the lower Yuba River-a six-month period over the winter. Though it was desirable to design a system that could sample for at least a year to capture the totality of seasonal fluctuations. In this paper, we present the design, implementation and deployment of a wireless sensor network that was installed to monitor temperature data on the Lower Yuba River. The mesh network was implemented using nodes that contained a MSP430 chipset with a radio operating at 433 MHz. We describe the network architecture which included a network storage function to address intermittent link failures. We describe the event-based software architecture of the mesh network mode specifically in relation to energy optimization. We also give details of the deployment and provide measurement data.

Objectives. Digitalization of the economy has led to a situation in which organizations accumulate huge amounts of digital data, the loss or damage of which leads to irreparable damage to the organizations. The issue of increasing data safety is relevant. One of the ways to improve the safety of data is backing them up. The study aimed to develop an effective strategy for backing up data for critical enterprise information systems.Methods. The method for solving the problem was to create backup copies of enterprise information systems using a flexible architecture based on the backup—as a service in external cloud structures—in combination with technical resources of the organization.Results. This article discussed backup solutions and tools, which include: backup volumes and schedule, target point and recovery time. The strategies and mechanisms of data backup were analyzed. The most common backup mechanisms are removable media, backups, external hard drive, hardware, backup software, cloud backup services. To create backups on a network, a large external hard drive is created and archival software is used to save changes to local files on that hard drive. This article covered: backup strategy, concept of backup storage, different types of backup storage methods, including network storage, external hard drives, and cloud storage. The main provisions and rules for backing up critical information systems were described. The rules for copying servers were given.Conclusions. This article discusses a data backup architecture for mission-critical enterprise information systems. The authors believe that there should be at least three backups, two of which are located in the “cloud.” The 3–2–1 strategy developed by the authors gives quite satisfactory results for the safety of critical data.

Virtual block devices are heavily used to fulfill the block storage needs of hypervisor-based virtual machine (VM) instances through either local or remote storage spaces. However, a high degree of VM co-location makes it increasingly difficult to physically provision all the necessary block devices using only local storage space. Also, the local storage performance degrades rapidly as workloads interleave. On the other hand, when block devices are acquired through remote storage services, the aggregated network traffic may consume too much cluster-wide network bandwidth in a cloud data center. In order to solve these challenges, we propose a caching scheme for virtual block devices within the hypervisor. The scheme utilizes the physical node’s finite local storage space as a block-level cache for the remote storage blocks to reduce the network traffic bound to the storage servers. This allows hypervisor-based compute nodes to serve the hosted VMs’ I/O (Input/Output) requests from its local storage as much as possible while enabling VMs to exercise large storage space beyond the capacity of local disks for new virtual disks. Caching virtual disks at block-level in a cloud data center poses several challenges in maintaining high performance while adhering to the virtual disk semantics. We have realized the proposed scheme, called vStore, on Xen hypervisor nodes with factual assessment on its design effectiveness and implementation efficiency. Our comprehensive experimental evaluations show that the proposed scheme substantially reduces the network traffic (49% on average), and incurs less than 12% overheads on the storage I/O performance.

Recently, a large amount of multimedia data is rapidly increasing due to cloud activation. For this reason, there is a need for a technique capable of handling large amounts of data and large storage devices. In this way, a network storage device such as a NAS or a SAN is used to configure a large-capacity storage device in a network environment. In this paper, a large capacity storage device is constructed by using network direct connection storage device. We performed benchmark experiments to verify the scalability of the constructed storage devices using network direct attached storage.

Aiming at the systemic weakness and low management efficiency of the video surveillance system for colleges, a comprehensive practicing platform for IP intelligent video surveillance was proposed based on the public security monitoring project by combining server virtualization, network storage and communication technologies. To achieve large-scale industrial video resource sharing and service control, three-stream mechanism was adopted to integrate five typical functional modules, i. e., information collection, transmission, management, storage and display. The platform provides an integrated training environment for IP intelligent video surveillance technology, and improves the convenience of daily operation and management of training platform effectively. [ABSTRACT FROM AUTHOR]

Storage disaggregation separates compute and storage to different nodes to allow for independent resource scaling and, thus, better hardware resource utilization. While disaggregation of hard-drives storage is a common practice, NVMe-SSD (i.e., PCIe-based SSD) disaggregation is considered more challenging. This is because SSDs are significantly faster than hard drives, so the latency overheads (due to both network and CPU processing) as well as the extra compute cycles needed for the offloading stack become much more pronounced. In this work, we characterize the overheads of NVMe-SSD disaggregation. We show that NVMe-over-Fabrics (NVMe-oF)—a recently released remote storage protocol specification—reduces the overheads of remote access to a bare minimum, thus greatly increasing the cost-efficiency of Flash disaggregation. Specifically, while recent work showed that SSD storage disaggregation via iSCSI degrades application-level throughput by 20%, we report on negligible performance degradation with NVMe-oF—both when using stress-tests as well as with a more-realistic KV-store workload. [ABSTRACT FROM AUTHOR]

During the past decade, network and storage devices have undergone rapid performance improvements, delivering ultra-low latency and several Gbps of bandwidth. Nevertheless, current network and storage stacks fail to deliver this hardware performance to the applications, often due to the loss of I/O efficiency from stalled CPU performance. While many efforts attempt to address this issue solely on either the network or the storage stack, achieving high-performance for networked-storage applications requires a holistic approach that considers both. In this article, we present FlashNet, a software I/O stack that unifies high-performance network properties with flash storage access and management. FlashNet builds on RDMA principles and abstractions to provide a direct, asynchronous, end-to-end data path between a client and remote flash storage. The key insight behind FlashNet is to co-design the stack's components (an RDMA controller, a flash controller, and a file system) to enable cross-stack optimizations and maximize I/O efficiency. In micro-benchmarks, FlashNet improves 4kB network I/O operations per second (IOPS by 38.6% to 1.22M, decreases access latency by 43.5% to 50.4μs, and prolongs the flash lifetime by 1.6-5.9× for writes. We illustrate the capabilities of FlashNet by building a Key-Value store and porting a distributed data store that uses RDMA on it. The use of FlashNet's RDMA API improves the performance of KV store by 2× and requires minimum changes for the ported data store to access remote flash devices. [ABSTRACT FROM AUTHOR]

Open computer laboratory is an important content of laboratory construction in colleges and universities. After the completion of the laboratory,its operation and maintenance service mode is also important. This paper introduces the service mode of open computer laboratory by taking College of William & Mary as an example. The college provides users with an online search service for the free computers in the open computer laboratory. It provides users with"automatic roaming"service between laboratories. It provides users with the network storage that can be accessed from on campus or off campus. It also provides users with comprehensive technology support service. Through the research on the open computer laboratory service mode of College of William & Mary,we have gotten many useful revelations to optimize the service mode and improve the service level. [ABSTRACT FROM AUTHOR]

Due to the fact that the iSCSI protocol does not provide security services and most network storage systems do not have the encryption capabilities either, we propose a realtime encryption module for the iSCSI, which enables the network storage system to provide users with transparent realtime encryption services after loading this module. We design an encrypted writing and decrypted reading process for the iSCSI target. Since the encryption module is independent of the original network storage system, the operating system's kernel does not need to change. The iSCSI initiator does not perceive the existence of encryption operation, thus clients based on standard iSCSI protocol can use the service directly. In addition, we use the security coprocessor of the multicore network processor to optimize the read and write performance. Experimental results show that introducing the encryption module to network storage system does not lead to serious loss of performance, and the system performance is satisfactory. [ABSTRACT FROM AUTHOR]

Current storage trends dictate placing fast storage devices in all servers and using them as a single distributed storage system. In this converged model where storage and compute resources co-exist in the same server, the role of the network is becoming more important: network overhead is becoming a main limitation to improving storage performance. At the same time, server consolidation dictates building servers that employ non-uniform memory architectures (NUMA) to scale memory performance and bundling multiple network links to increase network throughput. In this work, we use Tyche, an in-house protocol for network storage based on raw Ethernet, to examine and address (a) performance implications of NUMA servers on end-to-end path and (b) synchronization issues with multiple network interfaces (NICs) and multicore servers. We evaluate NUMA and synchronization issues on a real setup with multicore servers and six 10 GBits/s NICs on each server and we find that: (a) NUMA effects have significant negative impact and can reduce throughput by almost 2 $$\times $$ on our servers with as few as eight cores (16 hyper-threads). We design protocol extensions that almost entirely eliminate NUMA effects by encapsulating all protocol structures to a 'channel' concept and then carefully mapping channels and their resources to NICs and NUMA nodes. (b) The traditional inline approach where each thread accesses the NIC to post-storage requests is preferable to using a queuing approach that trades locks for context switches, especially when the protocol is NUMA-aware. Overall, our results show that dealing with NUMA affinity and synchronization issues in network storage protocols allows network throughput between the target and initiator to scale by a factor of 2 $$\times $$ and beyond 60 GBits/s. [ABSTRACT FROM AUTHOR]

ABSTRACT In this paper, we present an experimental case for the course of 'Network Storage and Security,' which benefited from an improved learning outcome for our students. The newly designed experiments-based contents are merged into the current course to help students obtain practical experiences about network storage. The experiments aim to build a network storage system based on available resources instead of any specialized network storage equipment. Technically, students can learn general practical knowledge of network storage on iSCSI (a network storage protocol based on IP technology) and also the technologies of embedded system. Through the experimental case, we found that it could fully enhance students' comprehensive and practical abilities, develop students' teamwork spirit and creativity, and especially improve the learning outcome of network storage curriculum. These learning and thinking methods can also be generalized and applied to other computer science related courses. © 2015 Wiley Periodicals, Inc. Comput Appl Eng Educ 24:186-194, 2016; View this article online at ; DOI [ABSTRACT FROM AUTHOR]

Erasure codes are widely used in storage systems for providing data reliability due to the advantage of high storage efficiency, while the access efficiency becomes the main shortcoming because of the extra data retrieve and decoding for accessing unavailable data. Most existing work designs erasure codes based on the ideal failure pattern where all storage nodes fail at the same rate. However in practice, the physical storage nodes fail at different rates due to the heterogeneous hardware, topologies and application behaviors. In this paper, we consider the heterogeneous failure pattern and analyze how the failure pattern impacts the overall access efficiency and reliability of erasure-coded storage systems. We propose HeMatch, a redundancy layout placement scheme in practical heterogeneous failure pattern for erasure-coded storage access efficiency. Specifically, we first study how the heterogeneous failure pattern impacts the access efficiency and propose a general model based on the Tanner graph to evaluate and predict the access efficiency in specific failure pattern and redundancy layout. Then, we propose the redundancy layout placement scheme, which matches the redundancy layout with the physical storage nodes in practical heterogeneous failure patterns based on the evaluation and prediction from our model. The experimental results demonstrate that the model we propose accurately evaluates the access efficiency, and HeMatch saves unavailable data access cost by up to 20% and improves the system reliability as well. [ABSTRACT FROM AUTHOR]

Content delivery is one of the most important technologies used in Mobile Social Networks (MSNs). Smart devices could enable mobile users to create and use a rich set of services through available resources in the surrounding environment opportunistically. This paper presents the framework of distributed buffer storage aided hybrid Mobile Social Networks (MSN). Based on this, we propose a new scheme with distributed storage for efficient end-to-end content delivery in intermittently connected MSNs. Our proposed hybrid architecture is able to offer fast and reliable delivery services by distributing buffer storage located close to mobile users of the opportunistic MSN. Simulation experiments are conducted to evaluate the performance of the proposed method, which indicate that it is helpful to improve network performance in terms of content delivery ratio, throughput and end-to-end delays. [ABSTRACT FROM AUTHOR]

Today's large-scale distributed storage systems are commonly built using commodity software and hardware. As a result, crash-stop and Byzantine failures in such systems become more and more prevalent. In the literature, regenerating codes have been shown to be a more efficient way to disperse information across multiple storage nodes and recover from crash-stop failures. In this paper, we propose a novel decoding design of product-matrix constructed regenerating codes in conjunction with integrity check that allows exact regeneration of failed nodes and data reconstruction in the presence of Byzantine failures. A progressive decoding mechanism is incorporated in both procedures to leverage computation performed thus far. Unlike previous works, our new regenerating code decoding has the advantage that its building blocks, such as Reed-Solomon codes and standard cryptographic hash functions, are relatively well-understood because of their widespread applications. The fault tolerance and security properties of the proposed schemes are also analyzed. In addition, the performance of the proposed schemes, in terms of the average number of access nodes and the reconstruction failure probability versus the node failure probability, are also evaluated by Monte Carlo simulations. [ABSTRACT FROM PUBLISHER]