ToSS-it: A Cloud-Based Throwaway Spatial Index Structure for Dynamic Location Data

The widespread use of GPS-enabled devices have led to a number of emerging applications that require monitoring and querying a large number of moving objects, such as in location-based services, mobile phone social networking, UAV surveillance, and car navigation systems. In such applications, indexes for moving objects must support queries efficiently and also cope with frequent updates. In this paper, we propose a cloud-based throwaway index structure, dubbed ToSS-it, where we generate the index from scratch in a short period of time rather than updating it with every location change of the moving objects. ToSS-it employs inter-node and intra-node multi-core parallelism paradigm to rapidly construct a distributed Voronoi Diagram. ToSS-it scales out by using a voronoi partitioning technique that minimizes the network message exchanges between the nodes (i.e., The major overhead in parallel generation of Voronoi Diagrams), and scales up since it fully exploits the multi-core CPUs available on each server. As a comparison point, with the state-of-the-art cloud-based spatial index structure (RT-CAN), if at least 7% of the objects are moving and issue updates to the index, it is faster to recreate ToSS-it from scratch than updating RT-CAN.