Order, Phase, Explanation, Factor, Focus, Fourier

Event sequence order

In any system, the event sequence order pattern is expected as a precondition to its normal behavior. Any out-of-order events should raise the suspicion bar as they might result in or lead to synchronization problems. It needs to be a sequence of trace messages not only from different threads but also between processes. For example, image load events in CDF / ETW traces can indicate the wrong configuration of a service startup order. The following diagram depicts a possible pattern scenario:

Event sequence phase

Sometimes we have some use case instances traced into one log file. Messages and activity regions from many use case trails intermingle and make analysis difficult, especially when UCID (Use Case ID), other identification tags, or linked messages are absent. However, initially, we are mostly interested in a sequence of significant events. After finding anchor messages, we can use time deltas to differentiate between trace statements from different use case trails. Here we assume the correct event sequence order. We call this pattern event sequence phase from analogy with wave phases. All such individual “waves” may have different “shapes” due to various delays between different stages of their use case and implementation narratives.

In the illustration above, we also identify the ... ...