Pruning and prioritizing event data for analysis

Dump file content and other event data is pruned and prioritized to assist analysis of hangs, crashes, and other circumstances. An event data pruner condenses or excludes certain event data. A cluster creator creates clusters from pruned and vectorized event data, using a clustering algorithm and a similarity metric, without any prior specification of the desired number of clusters. A cluster ranker ranks clusters according to event data volume and thread importance, thus prioritizing the event data for inspection. A results presenter configures a user interface to present ranked clusters, their associated data, data reduction statistics, regression analysis results, and other data reduction processing results. Thus, the innovative functionality assists analysis and prioritized inspection of event data by an analyst, surfacing organized event data that is relevant to the circumstance under investigation, or supporting comparison of clusters from before and after a change in the circumstance, or doing both.