关键词: 网格，动态服务发现，模型，协议

Abstract: Services join in and withdrawal from the grid frectuently, this makes dynamic grid service discovery a difficultissue. This paper presented a two-dimensional model for dynamic service discovery. Based this model, the service's registration, refreshing, cancellation protocols and discovery algorithm were described. A partial centralized and global distributed service management and discovery mechanism was applied in the model, parting function and property matching on different nodes, boosting the holistic performance of dynamic grid service discovery. The simulation results show the model is working well in performance of dynamic grid service discovery according to such indexes as the scale of grid,the busy degree of grid, dynamic degree of grid, the partition granularity of grid.

Key words: Grid, Dynamic service discovery, Model, Protocol