Supporting Effective Caching in a Wide-Area Location Service.

Globe is a wide-area distributed system in which objects are allowed to migrate between any machines, at any time. To support tracking and location of objects, we use a worldwide distributed location service. This service is implemented as a hierarchical search tree. Normally, an object registers its current location by storing an address in a nearby leaf node of the tree. A path of forwarding pointers from the root of the tree to that leaf node is then established. In other words, the root knows about all objects. Update operations can be relatively costly if many forwarding pointers need to be changed when moving to a new location. Likewise, lookup operations may often need to go to the root of the tree to locate an object. In this research, we investigate how the update and lookup operations for mobile objects can be optimized. Location caches and a dynamically-computed \stable" location to registered mobile objects are two aspects of this optimization.