1. A computer usable program product comprising a computer usable storage device including computer usable code for event-driven prediction of a metric in a data processing environment, the computer usable code comprising: computer usable code for observing a set of events in the data processing environment, the set of events being generated by a plurality of processes executing in the data processing environment; computer usable code for tracking a subset of the set of events for an observation period, the tracking resulting in bookkeeping information about the subset of events; computer usable code for detecting a pattern of events in the bookkeeping information by correlating events that pertain to a common process execution into a correlated set and detecting patterns within the correlated set; computer usable code for forming the pattern as a tuple representing a process in the plurality of processes, the metric corresponding to the process; computer usable code for selecting a prediction model corresponding to the tuple; computer usable code for supplying the prediction model with the tuple; and computer usable code for executing the prediction model to generate a predicted value of the metric.