Defining what is “eXtreme” is a difficult topic. For example, if I am simply “processing” simple events as incoming data with no correlation requirements, I have a significantly easier job than if I am doing complex event processing, abstracting higher level events over time from incoming events.
Here is an interesting example that was being discussed last week: during an on-site application test, an enterprise event processing application (using TIBCO BusinessEvents) was comfortably processing events at their arrival rate of ~750 eps (events per second) when a “testing glitch” caused the EMS (JMS) queue to back up; when the offending component (i.e. agent) was corrected and restarted (in situ) the CEP application maxed out its CPUs to clear the queue at a reported ~5K eps. This 5K figure compares quite well “as a number” with other complex applications (as opposed, maybe, to event stream processing of simple events), although probably it will be up to someone like the EPTS Use Case Working Group to make some classifications here.
My guess is that “eXtreme Event Processing” or “XEP” (in which we really mean “extreme CEP” involving correlation across events, XML processing, some number of business rules, large number of fields per base event message, 24+ hour retention, fault tolerance, and so forth) probably starts at ~1000 events per second. But ultimately its not just a matter of “how fast”, but also “work done”…
