Theoretically total bandwidth conserving locality in Distributed Storage System
Institution: | KTH Royal Institute of Technology |
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Department: | |
Year: | 2014 |
Keywords: | Minimum-Storage Regenerating (MSR); Minimum-Bandwidth Regenerating (MBR); repair locality; Engineering and Technology; Electrical Engineering, Electronic Engineering, Information Engineering; Other Electrical Engineering, Electronic Engineering, Information Engineering; Teknik och teknologier; Elektroteknik och elektronik; Annan elektroteknik och elektronik; Teknologie masterexamen - Trådlösa system; Master of Science - Wireless Systems |
Record ID: | 1352179 |
Full text PDF: | http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-160952 |
Distributed storage systems provide fast and reliable access to data by intro- ducing redundancy for stored les. The most common approach of adding re- dundant information is by repetition and erasure codes. Two main processes in a distributed storage system are reconstruction of original le and regenerat- ing a new node. These two processes require bandwidth, which are termed as reconstruction-bandwidth and repair-bandwidth. The current literature treat- s these two processes separately. That is, there are methods to reduce the reconstructing bandwidth without considering the repair-bandwidth, and also there are methods to reduce the repair-bandwidth. We study these two pro- cesses together and try to jointly minimize the reconstruction-bandwidth and repair-bandwidth. We observe a method that has the minimum reconstruction- bandwidth might have large amount of repair-bandwidth and vice versa. We propose codes which minimizes the sum of the repair-bandwidth and reconstruction- bandwidth. The main contribution of this thesis is nding an value of repair locality r (number of nodes connected during node repair) and devising two coding meth- ods in which total bandwidth approximates to be half reduced compared with MSR and MBR when k ! 1 under the condition that 1 6 r 6 k.