A Dynamic Erasure Code Based on Block Code.

Aiming at the problem that the parameters of existing erasure codes are poorly dynamic in adjustment, this paper proposes a dynamic erasure code based on the idea of block codes, named DLRC (Dynamic Local Reconstruction Code). We encode the data blocks in group according to four parameters which proposed in DLRC. The dynamic balance of storage overhead, fault-tolerance ability, fault-tolerance rate, and reconstruction overhead is achieved by adjusting the values of parameters which can meet the different performance requirements of the distributed storage systems. The experiments show that DLRC achieves different proportions of four main performances mentioned above by adjusting the values of four parameters. In addition, we retain global parity blocks and put them in the calculation of local parity blocks which makes all coded blocks can be locally reconstructed within the group. In this case, DLRC ensures high fault tolerance ability and fault tolerance rate while reducing the overall reconstruction over-head.