| Résumé | Many distributed systems support some concept of mobile objects, i.e. objects (e.g., a file) that can be transmitted over a network from one node to another. A directory service allows nodes to keep track of mobile objects : if a user requests the object and it is not on the local node, the directory protocol locates the object and moves it on the local node.
To implement a directory service a fundamental synchronization problem has to be solved : multiple concurrent requests should be totally ordered. This can be also seen as a distributed queuing problem.
Through few well-known algorithms, the talk will discuss issues related to the correctness and the efficiency of implementing a distributed directory service. Some open problems will be presented. |