Trace Analysis Patterns (Part 152)
Wednesday, August 2nd, 2017Sometimes we have variable sequences of Significant Events when we expect the certain constant number of such events in repeated normal and problem cases. For example, in repeated normal cases we expect more than 10 of events but in repeated abnormal cases - just 2 events. The latter cases would indicate that something happened inside the processing of the second event. But if one or more such cases contain 3 or 4 events that would point to some external influence that aborted the sequence of events. We call such variable event sequences Hedges by analogy with hedge variables or variadic variables. One of the recent example that we encountered involved multiple abnormal cases with just 2 events. We were about to investigate the internals of the second event but noticed that one of the cases contained 3 events. Further analysis indicated that the whole sequence was aborted by some external process after reaching the certain timeout. In the case of 3 events the first 2 happened too earlier and that allowed for the 3rd event to happen before the timeout was triggered:
- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -