Constructing a Highly-Available Location Service for a Distributed Environment

摘要

One possible advantage a distributed system has over a centralized system is the ability to move objects from one node to another. For example, we may want to move an object if the node where it resides is overloaded. This thesis proposes to use a location service to aid in finding objects that move. The service is highly available; it will tolerate system failures like node crashes and network partitions without shutting down completely. The service is also efficient; the response time of the service is reasonable, and it does not increase the number and sizes of messages excessively. We achieve high availability and efficiency by replicating the service state. The replication technique we have chosen is a new method, the multipart timestamp technique that is based on multipart timestamps and gossip messages. This technique provides us with higher availability and efficiency than traditional replication techniques without sacrificing consistency. We also extend this technique to allow reconfiguration.