【摘要】：近年來，隨著信息化的高速發(fā)展，數(shù)據(jù)量呈爆炸式增長，分布式存儲方式被廣泛應(yīng)用，同時數(shù)據(jù)可用性也得到了極大的重視。在此情況下，作為一種重要的冗余機制，糾刪碼被廣泛應(yīng)用于分布式存儲系統(tǒng)以獲得高可用性。但是，糾刪碼在讀、寫和失效恢復(fù)方面的代價較高，因此，為糾刪碼系統(tǒng)設(shè)計新的讀、寫和重構(gòu)方案以提高系統(tǒng)性能具有重要的研究意義和應(yīng)用前景。在基于糾刪碼的集群存儲環(huán)境中，，分別針對讀、寫和重構(gòu)提出了三種優(yōu)化方案，分別稱之為基于最小負載的大讀優(yōu)化方案、局部式小寫更新優(yōu)化方案和基于重定向的在線重構(gòu)方案。 在基于最小負載的大讀優(yōu)化方案中，首先結(jié)合糾刪碼集群系統(tǒng)的特點，定義了負載衡量基準，根據(jù)該基準，將集群系統(tǒng)中高負載節(jié)點的讀請求轉(zhuǎn)移到其他負載較低的節(jié)點上，最后解碼出所需的數(shù)據(jù)，使得在平衡節(jié)點負載的同時，降低用戶的訪問響應(yīng)時間。 在局部式小寫更新優(yōu)化方案（PUS）中，充分利用存儲節(jié)點的計算能力，將部分更新工作從更新節(jié)點轉(zhuǎn)移至存儲節(jié)點，減少由于更新所帶來數(shù)據(jù)讀、寫和傳輸開銷，有效縮短更新操作流程，不僅優(yōu)化用戶響應(yīng)時間，而且減輕更新節(jié)點壓力。實驗結(jié)果表明，相比于傳統(tǒng)更新方案，PUS能有效降低至少42%的小寫更新時間。 在基于重定向的在線重構(gòu)方案（ROW-R）中，按照最小化用戶I/O對重構(gòu)I/O干擾的策略，將面向失效節(jié)點的全部寫請求和部分讀請求重新定位至其他存活節(jié)點，從而在物理上將用戶工作流與重構(gòu)工作流在一定程度上分開，通過充分利用磁盤在連續(xù)寫時的高性能特性，加速重構(gòu)進程。實驗表明，ROW-R能有效優(yōu)化用戶響應(yīng)時間達52%，并能夠加速系統(tǒng)重構(gòu)速度約6%。
[Abstract]:In recent years, with the rapid development of information technology, the amount of data has exploded, distributed storage has been widely used, at the same time, data availability has been paid great attention. In this case, as an important redundancy mechanism, erasure codes are widely used in distributed storage systems to obtain high availability. However, the cost of erasure codes in reading, writing and failure recovery is high. Therefore, designing new read, write and reconstruct schemes for erasure code systems has important research significance and application prospects in order to improve the performance of erasure codes. In the cluster storage environment based on erasure codes, three optimization schemes are proposed for reading, writing and refactoring respectively, which are called large read optimization schemes based on minimum load, respectively. Local lowercase update optimization scheme and on-line reconfiguration scheme based on redirection. In the large-reading optimization scheme based on minimum load, firstly, considering the characteristics of erasure code cluster system, the load measurement benchmark is defined. According to this benchmark, the read requests of high-load nodes in cluster system are transferred to other nodes with lower load. Finally, the desired data is decoded to reduce the user's access response time while balancing the node load. In the local lowercase update optimization scheme (PUS), taking full advantage of the computing power of the storage node, part of the update work is transferred from the update node to the storage node, thus reducing the data reading, writing and transmission overhead caused by the update. Effectively shorten the update operation process, not only optimize user response time, but also reduce the pressure of the update node. The experimental results show that PUS can effectively reduce the lowercase update time by at least 42% compared with the traditional updating scheme. In the redirected online refactoring scheme (ROW-R), all write requests and partial read requests for failed nodes are repositioned to other surviving nodes in accordance with the strategy of minimizing user I / O interference to the refactoring Ido. Thus, the user workflow is separated from the refactoring workflow to a certain extent, and the refactoring process is accelerated by making full use of the high performance characteristics of disk in continuous writing. Experiments show that ROW-R can effectively optimize the response time of users up to 52%, and can accelerate the reconfiguration speed of the system by about 6%.
【學(xué)位授予單位】：華中科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2013
【分類號】：TP333

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相關(guān)博士學(xué)位論文 前2條

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2 李旭;系統(tǒng)級數(shù)據(jù)保護技術(shù)研究[D];華中科技大學(xué);2008年

本文編號：2461961