CHAPTER 6

Patterns of Events

This chapter discusses classifying the problems we all face in dealing with the expected and the unexpected in the event cloud—and trying to avoiding false alarms. We will cover:

  • Variables, templates, and patterns
  • Single event patterns
  • Patterns of multiple events
  • Pattern matching
  • Event patterns and state contexts
  • Events and time: creation time, arrival time, time intervals
  • Event patterns, state, and timing
  • Causality, independence, and beyond today’s event processing tools
  • Expressing event patterns—requirements for event pattern languages

This chapter gets into some technical aspects of event patterns. Although it may look technical at first sight, in fact it’s pretty simple stuff. If it gets to be hard going, skip it and move on—you can come back to it later. However, knowing some technical details about event processing helps to understand how a company can use events to solve some of the problems it may have to deal with. It also gives you some help in deciding what products have capabilities that would help with your problems.

Events contain information—here we’re talking about event objects. Very often, events add up to actionable information, not simply one event at a time, but many events over a time interval. Each event may carry just a little information, which by itself gives us nothing actionable, but a set of events happening in a specific pattern over time may add up to something of importance. Most applications of event processing are ...

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