Causal-Consistent Debugging of Distributed Erlang Programs

Debugging concurrent programs is an interesting application of reversibility. It has been renewed with the recent proposal by Giachino et al. to base the operations of a concurrent debugger on a causal-consistent reversible semantics, and subsequent work on CauDEr, a causal-consistent debugger for the Erlang programming language. This paper extends CauDEr and the related theory with the support for distributed programs. Our extension allows one to debug programs in which processes can run on different nodes, and new nodes can be created at runtime. From the theoretical point of view, the primitives for distributed programming give rise to more complex causal structures than those arising from the concurrent fragment of Erlang handled in CauDEr, yet we show that the main results proved for CauDEr still hold. From the practical point of view, we show how to use our extension of CauDEr to find a non trivial bug in a simple way.