Replay-Based Synchronization of Timestamps in Event Traces of Massively Parallel Applications

Event traces are helpful in understanding the performance behavior of message-passing applications since they allow in-depth analyses of communication and synchronization patterns. However, the absence of synchronized hardware clocks may render the analysis ineffective because inaccurate relative event timings can misrepresent the logical event order and lead to errors when quantifying the impact of certain behaviors. Although linear offset interpolation can restore consistency to some degree, inaccuracies and time-dependent drifts may still disarrange the original succession of events - especially during longer runs. In our earlier work, we have presented an algorithm that removes the remaining violations of the logical event order postmortem and, in addition, have outlined the initial design of a parallel version. Here, we complete the parallel design and describe its implementation within the SCALASCA trace-analysis framework. We demonstrate its suitability for large-scale applicat...

• Type: Conference
• Year: 2008
• Where: ICPPW
• Authors: Daniel Becker, John C. Linford, Rolf Rabenseifner, Felix Wolf
• Keywords: Distributed And Parallel Computing, Event Order Postmortem, ICPPW 2008, Inaccurate Relative Event, Logical Event Order