| 摘要 |
PROBLEM TO BE SOLVED: To detect bias of load between nodes in advance that causes deterioration of load distribution.SOLUTION: Nodes 1 can construct a plurality of virtual nodes identified by a plurality of virtual IDs by having the virtual IDs. On the basis of the virtual IDs, by obtaining size of an area a virtual node composed of each of the nodes 1 is in charge of and adding it, the size of the area each of the nodes 1 is in charge of is calculated, a first variation coefficient among a plurality of nodes 1 is calculated, and bias in load at a normal time is evaluated. Also, the nodes 1 function as owner nodes in charge of original data and buddies in charge of replicated data. On the basis of the virtual ID, size of an area where the owner node is in charge of the original data corresponding to the replicated data the buddy is in charge of among sizes of the areas the owner nodes are in charge of is calculated for each owner node, a second variation coefficient among the plurality of nodes 1 is calculated, and bias in load when the nodes leave is evaluated. |
