Debugging distributed applications with replay capabilities
Daniel Neri, Laurent Pautet, Samuel Tardieu · 1997
This paperfocuseson the latest developmentsmade by the ENST research team to GLADE, the implementation of the Distributed Systems Annexfor the GNATAda compiler; we have extended GLADE's communication subsystem and added recording facilities and replay capabilities. This makes debugging distributed ' applications much easier because of the possibility to replay separately each partition by simulating erternaI events at consisrertt dates without loosing the possible detemrinism of the original program, and it also eases the debugging in caseswhere it is not practical IO re-run the whole program or when it is impossible to get exactly the same behaviourfrom one of the part lfor example when one or several parts of the application run on embedded targets and send messages depending on sensor inputs while the other parts run on fixed workstations).'A sequeatialprogramis aprogramwhich has only one thrcadof control.'An input from the envimnment may consist into data read from a file, user interaction, numbers coming from a pseudo-random generator and even tha lime of the day since the program may behave differently depending on this limo.'A paralhl program is a program which has severnl threads of control.h dlstributed program is thus a particular form of parallel program..