Methods, systems, and computer program products for flexible event data content management for relevant event and alert analysis within a distributed processing system are provided. Embodiments include receiving, by an interface connector, a raw event from a component of the distributed processing system; analyzing, by the interface connector, custom data within the raw event to determine a location to store the custom data, the custom data in a first data format; storing, by the interface connector, extended data within the raw event in a common event data format, the extended data indicating the location of the custom data; receiving, by an event analyzer, the event; and determining whether there are custom customer rules that need the custom data; and if there are such custom customer rules, retrieving the custom data based on the extended data from the event; and applying the custom customer rules to the extended data; if there are no such custom customer rules, applying the base rules to a base portion of the event.