Massive Spatial Data Cache Replacement Policy Based on Tile Lifetime and Popularity

Challenges such as limited simultaneous users and long tile request response times,exist in spatial information services.Cache mechanism is deployed in the services' client.The establishment,query and update of cache index for spatial data tile are analyzed.Tile cache lifetime excess and popularity replacement(TCLEPR) policy is proposed.In TCLEPR,cache tile has a longest lifetime excess,which is current cache life subtracted by average cache life,and the lowest popularity is replaced by new requested tile.Simulation results show that TCLEPR can improve tile request cache hit ratioes and byte hit ratioes,which in return shortens tile request response times and support more simultaneous users.