Dynamic reconfiguration: A tutorial

A key challenge for distributed systems is the problem of reconfiguration. Clearly, any production storage system that provides data reliability and availability for long periods must be able to reconfigure in order to remove failed or old servers and add healthy or new ones. This is far from trivial since we do not want the reconfiguration management to be centralized or cause a system shutdown. In this tutorial we look into existing reconfigurable storage algorithms [7, 8, 1, 9, 6, 10]. We propose a common model and failure condition capturing their guarantees. We define a reconfiguration problem around which dynamic object solutions may be designed. To demonstrate its strength, we use it to implement dynamic atomic storage. We present a generic framework for solving the reconfiguration problem, show how to recast existing algorithms in terms of this framework, and compare among them.