Abstract. Understanding the dynamic behavior of parallel programs is a critical issue both for debugging and for optimization. A visualization tool displaying an animated sequence of the global states the program runs through offers valuable support for th

state snapshot selected in the visualizer.This will be achieved by automatically restarting the application from the last available checkpoint prior to the selected snapshot and by using the deterministic execution controller to ensure that the selected state is reached even in the presence of nondeterminism due to message races.In this way debugging large programs with high execution times will be efficiently supported. References

1. A.Beguelin,J.Dongarra,A.Geist,R.Manchek,and K.Moore.HeNCE:A Heterogeneous

Network Computing Environment.Technical report UT-CS-93-205,Univ.of Tennessee, Computer Science Department,Aug.1993.

2. A.Beguelin,J.Dongarra,A.Geist,R.Manchek,and V.Sunderam.Recent Enhancements

to PVM.Intl.J.of Supercomputing Applications and High Performance Computing,1995.

3. A.Bode and P.Braun.Monitoring and Visualization in TOPSYS.In Proc.Workshop on

Monitoring and Visualization of Parallel Processing Systems,pages97–118,Moravany nad V´a hom,CSFR,Oct.1992.

4. D.Cheng and R.Hood.A Portable Debugger for Parallel and Distributed Programs.In

Proc.Supercomputing’94,pages723–732,Washington D.C.,Nov.1994.IEEE.

5. A.Geist,J.Kohl,and P.Papadopoulos.Visualization,Debugging,and Performance in PVM.

In Proc.Visualization and Debugging Workshop,Oct.1994.

6.M.T.Heath.Recent Developments and Case Studies in Performance Visualization using

ParaGraph.In Proc.Workshop on Monitoring and Visualization of Parallel Processing Systems,pages175–200,Moravany nad V´a hom,CSFR,Oct.1992.

7.M.T.Heath and J.A.Etheridge.Visualizing the Performance of Parallel Programs.IEEE

Software,8(5),Sept.1991.

8. D.P.Helmbold,C.E.McDowell,and J.Z.Wang.Analyzing Traces with Anonymous

Synchronization.In Proc.Intl.Conf.on Parallel Processing,pages70–77,Aug.1990.

9. D.Kimelman and D.Zernik.On-the-Fly Topological Sort–A Basis for Interactive Debug-

ging and Live Visualization of Parallel Programs.In Proc.ACM/ONR Workshop on Parallel and Distributed Debugging,pages12–20,San Diego,CA,May1993.

mport.Time,Clocks,and the Ordering of Events in a Distributed mun.

ACM,21(7):558–565,July1978.

11.T.Ludwig,M.Oberhuber,and R.Wism¨u ller.An Open Monitoring System for Parallel and

Distributed Programs.To appear in Proceedings of EuroPar’96,Lyon,France,Aug.1996.

12.T.Ludwig,R.Wism¨u ller,R.Borgeest,mberts,C.R¨o der,G.Stellner,and A.Bode.

T HE T OOL-SET–An Integrated Tool Environment for PVM.In Proc.EuroPVM’95Short Papers,Lyon,France,Sept.1995.ENS Lyon.Technical Report95-02.

rmatik.tu-muenchen.de/˜wismuell/publicatio ns/europvm95.ps.gz.

13.T.Ludwig,R.Wism¨u ller,V.Sunderam,and A.Bode.OMIS–On-line Monitoring Interface

Specification.Technical Report TUM-I9609,SFB-Bericht Nr.342/05/96A,Technische Universit¨a t M¨u nchen,Feb.1996.

rmatik.tu-muenchen.de/˜omis/HTML/OMIS/Vers ion-1.0/version-1.0.ps.gz.

14.C.Scheidler and L.Sch¨a fers.TRAPPER:A Graphical Programming Environment for In-

dustrial High-Performance Applications.In Proc.PARLE’93,Parallel Architectures and Languages Europe,volume694of LNCS,pages403–413,M¨u nchen,June1993.

This article was processed using the L A T E X macro package with LLNCS style