Testing Distributed Systems Through Symbolic Model Checking

The observation of a distributed system’s finite execution can be abstracted as a partial ordered set of events generally called finite (partial order) trace. In practice, this trace can be obtained through a standard code instrumentation, which takes advantage of existing communications between processes to partially order events of different processes. We show that testing that such a distributed execution satisfies some global property amounts therefore to model check the corresponding trace. This work can be time consuming; we therefore provide an efficient symbolic Ctl model-checking algorithm for traces. This method is based on a symbolic data structure, called Interval Sharing Trees, allowing to efficiently represent and manipulate sets of k-uples of naturals. Efficient symbolic operations are defined on this data structure in order to deal with all Ctl modalities. We show that in practice this data structure is well adapted for Ctl model checking of traces.