The goal of the GINSENG project is a performance- controlled sensor network suitable for time-critical applications like plant automation and control. Such sensor networks must monitor performance constantly and collect data in order to detect, diagnose and rectify problems. The GINSENG system contains a number of mechanisms used to collect, transport and analyse performance critical data. Performance data processing is carried out in a manner that ensures time-critical application data processing is not affected. In this paper we present the different performance debugging mechanisms included in the GINSENG system.