基于对象存储设备上的服务质量研究

基于对象存储（Object—basedStorage,OBS）作为下一代互联网存储协议标准逐渐被人们所接受,基于对象存储设备（Object—based Storage Device,OSD）所具有的可扩展性和智能性能很好地支持应用程序的服务质量（Quality of Service,QoS）需求。本文分析了基于对象存储系统的QoS需求,讨论了如何把应用客户的QoS需求转化为QoS属性,扩展了OSD SCSI协议集标准,以支持QoS,接着采取量化分析方法对QoS进行了分析,详细分析应用客户和OSD之间QoS信息交互的工作过程,最后,紧密结合OSD的特性,给出OSD上的QoS三层模型Q-Model和一优化算法BRP。     

对象存储系统的研究

SCSI, ATA/IDE等现有的基于块的存储接口已成为提升存储系统性能、降低存储管理成本的障碍。对象存储技术有望改变现状，成为下一个标准存储接口，使得建立拥有自主管理、数据共享、安全和智能化等特征的存储网络成为可能。该文分析对象存储的特点，设计并实现一个简单的对象存储系统原型，该对象存储系统遵照对象存储的OSD T10标准，由客户端、目标端和IP网络构成，采用iSCSI作为通信协议。读写性能测试分析结果表明，该系统可以满足实际需求。     

一种高性能对象存储系统

当大量用户并行访问对象存储设备(OSD)时,OSD可能成为限制系统性能的瓶颈。该文提出一种基于网络磁盘阵列的对象存储系统,网络磁盘阵列包括外设和网络2个通道,可直接与客户端进行数据传输。该系统具有基于对象存储系统的特点,且系统容量可扩展性和整体性能较高。     

基于对象存储系统的服务质量框架研究

简要介绍了基于对象存储系统的框架结构,并分析了系统的特点。在结合网络QoS和存储QoS的基础上,讨论了整个系统的QoS要求。针对这些要求,提出基于对象存储系统的QoS框架,分别在对象属性、OSD命令和OSD设备上得以实现。     

基于对象存储系统中属性管理的研究与实现

针对现有属性管理方法上的缺陷和不足,提出了一种新的属性管理方法--哈希桶.哈希桶方法对对象的属性进行集中管理,不仅降低了管理存储成本,更有效地提高了系统的吞吐率.经过仿真测试表明,哈希桶对象属性管理方法性能远优于现有的属性管理方法.     

基于对象存储系统的动态负载均衡算法

负载均衡是大规模基于对象存储系统必须要考虑的重要问题。本文为此以系统总响应时间为代价函数,以对象被访问频率为依据,建立了一种将对象复制与对象迁移统一在内的动态负栽均衡模型,并充分利用存储设备的智能实现系统的动态负载均衡。仿真结果表明,在存在大量热点访问和对象分布不均匀的情况下,启用对象复制和对象迁移的负载均衡算法能最大程度地减少系统的平均总响应时间。     

安全iSCSI对象存储系统的研究与实现

论述了一种对象存储系统的架构和存储安全关键技术,对系统中的各组成部件进行详细的论述.系统设计的核心思想是充分利用对象存储的优势并实现多重安全策略,保证存储对象的机密性、完整性和较好的系统性能.对系统的测试表明该原型系统具有较高的效率和实用性.     

一种基于对象的多媒体存储系统优化策略

设计一个实用的分布式多媒体服务系统,存储子系统是其中的一个研究重点.根据多媒体系统的存储特点,从全新的视角提出一种存储子系统设计方案--基于对象的多媒体存储系统(Multimedia Object-based Storage System,MOSS),并分析了MOSS的系统架构和工作流程.与传统的多媒体存储技术相比,对象存储不仅能有效地改善系统I/O性能,还具有较好的安全性.以对象存储原型系统为基础,讨论了热点对象文件的分布和均匀分块优化策略.通过建立与系统相对应的数学模型,对数传率、I/O请求丢失率等性能指标作了定性分析.该研究工作对消除多媒体服务系统I/O瓶颈、进行存储子系统设计具有实际的指导意义.     

一种基于IP网络的统一对象存储访问模型的研究

随着计算机应用的普及和存储需求的膨胀,存储系统正在由NAS和SAN转向了OBS。本文介绍了三种存储系统的访问模式,在OBS基础上,提出了存储设备对象,这不仅丰富了对象的内涵,还总结出一种统一对象存储访问模型,对不同存储对象设备实行访问协议的映射,使之更具有普适性。     

基于对象存储的集群存储系统设计

集群存储是解决大规模数据存储的重要方法。本文提出一种基于对象存储的集群存储系统结构,将文件分为目录路径元数据、文件元数据与数据对象三部分并独立管理。性能比较与分析表明,该方法能够支持超大规模的文件及超大容量的目录,明显地减少网络访问消息数量,提高访问性能,并且解决了因为修改目录而导致的大量元数捂迁移问题。     

一种OSD文件系统的设计

OSD文件系统主要承担通用文件系统中存储管理部分的功能,其与通用文件系统存在很大的差异,针对OSD的特征,设计了一种适用于小对象的OsD文件系统,其中提出了“盘区记录表”这种对象ID到对象数据的映射方式和一种新的空间分配策略,同时结合空间分配方式的特点提出了一种主动对象数据调整策略.实验表明,该文件系统在管理小型对象时能有效提高读写性能.     

Design,implementation and evaluation of a virtual storage system

Large organizations always have a strong demand for storage from data‐intensive applications and instruments. In this paper, we present the design, implementation, and evaluation of a new virtual storage system, Storage@desk, which can aggregate a large number of distributed machines within an organization to provide storage services with quality of service guarantees. Because storage virtualization is the prominent goal, Storage@desk provides clients with the abstraction of a hard drive by utilizing the Internet SCSI protocol. As such, data access to new storage services is transparent so that clients do not need to modify any existing applications nor change their current practices. Storage@desk replicates data and employs version‐based journaling for high availability. It utilizes a market‐based model for resource management and a feedback controller for automated performance control. We have developed a prototype of Storage@desk that implements the core components. Copyright © 2010 John Wiley & Sons, Ltd.     

Design and performance analysis of RAID based on OSD

Today＇s SAN architectures promise unmediated host access to storage. To keep this promise, however, several issues and opportunities raised by SANs must be addressed, including security, scalability and management. Object storage, such as introduced by the NASD work, is a means of addressing these issues and opportunities. RAID using Object-Based Storage Devices is described, about which some issues are discussed and then its performance by queuing model is investigated.     

A synthesizing control model of networked control systems to guarantee QoP and QoS

The whole performance of the networked control system （NCSs） depends on two interaction factors, namely the quality of control performance （QoP） and quality of network service （QoS）. So, to optimize the whole perfor-mance of NCSs, the problem of guaranteeing QoP and QoS plays an important role in the design of NCSs. However, up to now, little work has been done in this field. In this paper, a synthesizing control model of NCSs to guarantee QoP and QoS is proposed, and a feasible condition of optimizing whole performance of NCSs is also suggested. Finally, the simulation results show that the proposed model is effective.     

Provisioning QoS guarantee by multipath routing and reservation in Ad hoc networks

In this paper, a QoS multipath source routing protocol (QoS-MSR) is proposed for ad hoc networks. It can collect QoS information through route discovery mechanism of multipath source routing (MSR) and establish QoS route with reserved bandwidth. In order to reserve bandwidth efficiently, a bandwidth reservation approach called the multipath bandwidth splitting reservation (MBSR) is presented, under which the overall bandwidth request is split into several smaller bandwidth requests among multiple paths. In simulations, the anthors introduce Insignia, an in-bind signaling system that supports QoS in ad hoc networks, and extend it to multipath Insignia (M-Insignia) with QoS-MSR and MBSR. The results show that QoS-MSR routing protocol with the MBSR algorithm can improve the call admission ratio of QoS traffic, the packet delivery ratio, and the end-to-end delay of both best-effort traffic and QoS traffic. Therefore, QoS-MSR with MBSR is an efficient mechanism that supports QoS for ad hoc networks.     

支持QoS确保的存储服务器服务资源分配算法

在电子商务、工业制造领域中,具有海量存储与高I/O吞吐能力的数据存储服务器得到了广泛应用。数据存储服务器提供QoS支持对应用需求而言很重要,但是实践中却很少有数据存储服务器提供了QoS支持。提出了一种支持服务质量区分并对高优先级用户提供服务质量保证的存储服务区服务资源分配算法,由于对高优先级用户请求与低优先级用户请求采用了可变服务质量区分因子,因而算法在提供服务优先级区分与确保高优先级请求服务质量的同时,减小了低优先级请求的请求丢弃率,同时最大化了服务资源利用率。     

基于服务质量的Web服务发现研究与实现

随着Web服务的广泛应用,网络上提供的服务数量越来越多,如何在动态的环境下从海量的Web服务中找到满足用户需求的最优服务就成了Web服务应用急需解决的问题.介绍了服务质量的量化评价方法,并且在不改变传统Web服务架构的基础上,建立了一种基于服务质量的Web服务三层匹配模型,最后实验结果证明了该模型的可行性.     

嵌入式设备NAND Flash存储系统的设计与实现

为了实现一种嵌入式设备存储系统的解决方案,对嵌入式设备广泛采用的大容量存储设备NAND Flash进行了深入的研究.设计了一种嵌入式设备中NAND Flash存储系统的解决方案,介绍了其功能用途和系统结构,分层介绍了系统的具体设计,重点介绍了比较独特的块设备驱动层和FTL层的设计方法以及对驱动初始化的优化.通过实际设计NAND Flash存储系统Linux驱动,说明了该系统设计实际应用时的出色效果.     

A novel distributed architecture of large-scale multimedia storage system using autonomous object-based storage devices

In a large-scale multimedia storage system (LMSS) where the user requests for different multimedia objects may have different demands, placement and replication of the objects is an important factor, as it may result in an imbalance in loading across the system. Since replica management and load balancing is a crucial issue in multimedia systems, normally this problem is handled by centralized servers, e.g., metadata servers (MDS) in distributed file systems. Each object-based storage device (OSD) responds to the requests coming from the centralized servers independently and has no communication with other OSDs among the system. In this paper, we design a novel distributed architecture of LMSS, in which the OSDs have some kind of intelligences and can cooperate to achieve a high performance. Such an OSD, named as autonomous object-based storage device (AOSD), can replicate the objects to and balance the requests among other AOSDs, and handle fail-over and recovery autonomously. In the proposed architecture, we move the request balancing from centralized MDS to AOSDs and make the system more scalable, flexible, and robust. Based on the proposed architecture, we propose two different object replication and load balancing algorithms, named as “Minimum Average Waiting Time” (MAWT) and “One of the Best Two Choices” (OBTC), respectively. We validate the performance of the algorithms via rigorous simulations with respect to several influencing factors. Our findings conclusively demonstrate that the proposed architecture minimizes the average waiting time and at the same time carries out load balancing across servers.