Analysis of a Session-Layer Protocol in mCRL2 Verification of a Real-Life Industrial Implementation

This paper reports the analysis of an industrial implementation of the session-layer of a load-balancing software system. This software comprises 7.5 thousand lines of C code. It is used for distribution of the print jobs among several document processors (workers). A large part of this commercially used software system has been modeled closely and analyzed using process-algebraic techniques. Several critical issues were discovered. Since the model was close to the code, all problems that were found in the model, could be traced back to the actual code resulting in concrete suggestions for improvement of the code. All in all, the analysis significantly improved the quality of this real-life system.