Andres Terrasa UPVLC aterrasa@dsic.upv.es Ana Garcia-Fornes UPVLC agarcia@dsic.upv.es Agustin Espinosa UPVLC aespinos@dsic.upv.es Ismael Ripoll UPVLC iripoll@disca.upv.es 2002 OCERA Consortium RTLinux Real-Time, POSIX, debug, trace, time analysis As realtime applications become bigger and more complex, the availability of event tracing mechanisms becomes more important in order to perform debugging and run- time monitoring. Recently, IEEE has incorporated tracing to the facilities defined by the POSIX standard. The result is called the POSIX Trace standard. Tracing can be defined as the combination of two activities: the generation of tracing information by a running process, and the collection of this information in order to be analysed. The tracing facility plays an important role in the OCERA architecture. Besides its primary use as a debugging and tuning tool, the tracing component jointly with the application-defined scheduler component constitute the key tools for building fault-tolerance mechanisms.