中文摘要：

分布式存储系统为保证数据可靠性,需要对数据进行冗余存储来应对由于节点失效所带来的数据不可靠性.基于矩阵积构造的精确修复最小带宽再生码除了能够显著降低系统的存储冗余,而且编码的构造参数之间没有约束限制,还能够显著降低修复带宽的开销,具有广阔的应用前景.然而,基于此编码方案所设计的分布式存储系统的性能开销并没有得到充分的研究和分析.针对该编码在分布式存储系统中数据上传、修复、下载3个阶段,分别比较CPU使用率、文件大小、缓冲区大小以及有限域大小对上述3个阶段中运算速度的影响,发现通过对相关参数进行合理配置,可以使得基于相应编码方案的分布式存储系统能够获得良好的运行性能.

英文摘要：

Distributed storage systems need to introduce redundancy to ensure data reliability against node failures. To repair failed nodes, a significant amount of bandwidth is consumed. Regenerating codes are able to achieve the optimal tradeoff between the storage overhead and the repair bandwidth overhead. Based on the current situation that bandwidth resources are more precious than computing resources in distributed storage systems, exact minimum bandwidth regenerating （E-MBR） codes, which can be implemented by a product-matrix construction, enjoy the advantages of regenerating codes as well as systematic codes, and have no restrictions for all construction parameters, making themselves a promising candidate towards the application in distributed storage systems. However, the performance overhead of distributed storage systems based on this coding scheme has not been investigated and analyzed. This paper gives a formal description of coding operations, which can be categorized into three distinct phrases： uploading, downloading and repairing. We hereby analyze the impact of the CPU utilization, the file size, the buffer size and the Galois field size to the computing rates in the three distinct phrases above. We find that distributed storage systems based on E-MBR codes are able to achieve a high computing throughput if we configure the construction parameters of E-MBR codes appropriately.