Asynchronous construction of consistent global snapshots in the Object and Action Model

The Object and Action Model (OAM) is well-known as an adequate paradigm to build fault-tolerant configurable distributed applications. The reconfiguration of an application depends on the construction of a consistent global snapshot of its global state. An atomic action that reads the states of all objects of the application is a simple and straightforward way to obtain such a global snapshot, but reduces concurrency and interferes with the underlying computation. In the Process and Message Model (PMM), consistent snapshots can be constructed asynchronously by a component that passively receives process states. This paper presents OAM-based asynchronous global snapshot algorithms that are equivalent to PMM-based algorithms, built using a precedence relation defined for atomic actions. Arjuna, an object-oriented action-based distributed programming environment, has been used to implement these OAM-based global snapshot algorithms, allowing us to conclude that our approach is promising.