A Transparent On-Demand Co-Allocation Scheme for Data Grids

• Main Authors: Yi-Sheng Lin, 林益聖
• Other Authors: Jyh-Biau Chang
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/39333086838544007746

碩士 === 國立成功大學 === 電腦與通信工程研究所 === 96 === With the conventional data grid system, a data-intensive application usually accesses data by using either the pre-staging scheme or the fragmented data sharing scheme. The pre-staging scheme simultaneously downloads an entire shared file from multiple data sources even when only a tiny file fragment is required. Obviously, the pre-staging scheme consumes unnecessary data transmission time and storage space. The fragmented data sharing scheme, on the other hand, downloads only the necessary fragments from a single data source. However, the fragmented data sharing scheme does not fully exploit available network bandwidth. Accordingly, this thesis presents a data sharing system which uses a hybrid scheme, designated as the On-Demand Co-Allocation scheme (ODCA). The ODCA scheme uses multiple data streams to concurrently fetch different necessary file fragment, thereby reducing data transmission time, wasted network bandwidth and required storage space. Beside, the ODCA scheme provides a transparency that facilitates the grid-unaware applications can use the Data Grid without any modification or re-compiling. Experimental results show the ODCA scheme successfully reduces turnaround time in data-intensive applications.