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 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 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.