SDCUP: Software-Defined-Control Based Erasure-Coded Collaborative Data Update Mechanism

The storage system often uses erasure coding to provide the necessary fault tolerance. The erasure-coded update involves data transmission and data calculation of multiple nodes. Frequent updates will cause massive communication overhead. This paper mainly considers two issues: (1) In the scenario of frequent small-size updates, there are repetitive behaviors upon update, which causes bandwidth consumption to increase exponentially as the number of update nodes increases; (2) with the increase of data scale, there are local link busy phenomena caused by unbalanced use of links during update, which can prone to bottleneck links. In order to improve the inefficient update due to network bottlenecks. We propose SDCUP, a software-defined-control collaborative update mechanism that reduce update time for erasure-coded data with network load balance. Specially, SDCUP uses the software-defined control method to select the update transmission path according to the actual link load and adjust the data flow transmission rate by monitoring the degree of network load balance periodically. To further reduce the cross-rack update traffic, SDCUP unloads the calculation to the switch to realize the data aggregation in the rack, and it parallelizes sub-update operations to efficiently and cooperatively update. To evaluate the performance of SDCUP, we conduct simulation experiments on Mininet with real-world traces. The simulation results show that SDCUP can achieve a better load balance in multiple scenarios. Compared with the other data update schemes, the proposed method can improve the system throughput by up to 21% and reduce the update time by up to 47%.