Flash Cache Hybrid Storage System For Video-On-Demand Server

A video-on-demand (VOD) system allows users to access any video at any time. This system enables users to view videos in the real-time streaming mode for extended durations. One of the important components of the VOD systems is the hybrid storage server. This component consists of HDD, SSD, and RAM, collectively fulfilling the requirement of simultaneous fast data access and large data distribution to numerous users. However, current hybrid storage systems still pose numerous challenges. (1) The integration and roles of the HDD, SSD, and RAM are relatively weak in terms of optimizing fast access prior to streaming to a large number of simultaneous users. (2) The HDD and SSD exhibit poor data layout and streaming controller in supporting the production of a high number of simultaneous streams. This thesis proposes (1) an enhanced hybrid storage system (EHSS) for the VOD servers. The HDD, SSD, and RAM are managed and integrated using an effective mechanism, in which the top 10% most popular videos are utilized to achieve fast data access and service to a large number of simultaneous users. (2) The flash cache hybrid storage system (FCHSS) is also proposed. Unlike the EHSS architecture, the FCHSS architecture has no RAM, which is removed and replaced by a flash-based SSD. The flash-based SSD is used instead of the RAM as a cache for the HDD to achieve fast data access and service to a large number of simultaneous users. (3) The new data layout stores thousands of video segments in the HDD and SSD

A Review of Low-end, Middle-end and High-end IoT Devices

Internet of Things (IoT) devices play a crucial role in the overall development of IoT in providing countless applications in various areas. Due to the increasing interest and rapid technological growth of sensor technology, which have certainly revolutionized the way we live today, a need to provide a detailed analysis of the embedded platforms and boards is consequential. This paper presents a comprehensive survey of the recent and most-widely used commercial and research embedded systems and boards in different classification emphasizing their key attributes including processing and memory capabilities, security features, connectivity and communication interfaces, size, cost and appearance, operating system (OS) support, power specifications and battery life and listing some interesting projects for each device. Through this exploration and discussion, readers can have an overall understanding on this area and foster more subsequent studies

Survey on Deduplication Techniques in Flash-Based Storage

Data deduplication importance is growing with the growth of data volumes. The domain of data deduplication is in active development. Recently it was influenced by appearance of Solid State Drive. This new type of disk has significant differences from random access memory and hard disk drives and is widely used now. In this paper we propose a novel taxonomy which reflects the main issues related to deduplication in Solid State Drive. We present a survey on deduplication techniques focusing on flash-based storage. We also describe several Open Source tools implementing data deduplication and briefly describe open research problems related to data deduplication in flash-based storage systems

Selected Papers from the First International Symposium on Future ICT (Future-ICT 2019) in Conjunction with 4th International Symposium on Mobile Internet Security (MobiSec 2019)

The International Symposium on Future ICT (Future-ICT 2019) in conjunction with the 4th International Symposium on Mobile Internet Security (MobiSec 2019) was held on 17–19 October 2019 in Taichung, Taiwan. The symposium provided academic and industry professionals an opportunity to discuss the latest issues and progress in advancing smart applications based on future ICT and its relative security. The symposium aimed to publish high-quality papers strictly related to the various theories and practical applications concerning advanced smart applications, future ICT, and related communications and networks. It was expected that the symposium and its publications would be a trigger for further related research and technology improvements in this field

Cost-Age-Time Data Organized Garbage Collection

NAND flash based solid state drives (SSDs) require out-of-place updating due to the characteristics of flash memories. In addition, due to the mismatched granularity between read/write and erase operations, a cleaning policy involving garbage collection and wear leveling has to perform data migration incurring high overhead. Another challenge is that flash devices can tolerate a limited number of erases. This paper proposes the Cost-Age-Time Data Organized Garbage Collection (CATDOG) scheme, which clusters data based on their update frequencies to reduce the overhead of data migration, trades off between endurance and performance, and efficiently erases multiple blocks to reduce garbage collection latency. To the best of our knowledge, this is the first paper to provide a holistic discussion on the effects of combining all three factors. Our simulation study shows that CATDOG achieves a maximum of 3.54 times higher throughput performance and 1.18 times greater endurance than a selected baseline for a heavy write workload