2. Event Processing Course ( Advanced topics in CS 6 - 236606) Lecture one – Introduction (relates to chapters 1 and 2)

3. 2 Copyright ©2009 Opher Etzion The motto of this course Focus on emerging technology Dive deep inside Internalize and retain over time

4. 3 Copyright ©2009 Opher Etzion Emerging technologies in enterprise computing (Gartner Hype Cycle, Summer 2009)

5. 4 Copyright ©2009 Opher Etzion Dive deep

6. 5 Copyright ©2009 Opher Etzion Internalize by: Experiment Product Developer View Application Developer View

7. 6 Copyright ©2009 Opher Etzion Entry point Architectural and programming Principles Chapter 1 PART 1: ENTRY POINT PART 2: THE BUILDING BLOCKS Engineering and implementation considerations Challenging topics Emerging directions Chapter 10 Chapter 2 PART 3: ADDITIONAL TOPICS Chapter 11 Chapter 12

8. 7 Copyright ©2009 Opher Etzion Lecture outline The notion of event Event-driven computing Event processing and its positioning in IT enterprise computing Event-driven architecture Model driven approach and major building blocks The FFD example

9. 8 Copyright ©2009 Opher Etzion Event and situation An event is an occurrence within a particular system or domain; it is something that has happened, or is contemplated as having happened in that domain. The word event is also used to mean a programming entity that represents such an occurrence in a computing system. A situation is an event occurrence that might require a reaction

10. 9 Copyright ©2009 Opher Etzion The fast food alternatives

11. 10 Copyright ©2009 Opher Etzion Example 1: Smart healthcare – Preterm Infants Patient is hooked up to multiple monitors (in hospital or at home) - the physician can set up event- based rules on multiple measurements and patient’s history when to send an alert and to whom: Defined Pattern

12. 11 Copyright ©2009 Opher Etzion Example 2: RFID on luggage Orchestrate: Passenger has been re- routed to another destination – send the luggage Orchestrate: Bag has reached to the wrong aircraft Notify: Bag has been checked but did not reach the ULD within 20 minutes Notify: Bag has been checked but did not reach the connecting flight THE LUGGAGE PERSPECTIVE: Across the 24 largest airlines more than 5.6 million bags went missing in 2006, this is an average of 15.7 bags per 1,000 travelers. 15% of the bags are never found. BBC News, April 4, 2007

13. 12 Copyright ©2009 Opher Etzion Example 3: Safety zone management

14. 13 Copyright ©2009 Opher Etzion Example 4: Alerts in banking Bank Account alerts;  Weekly withdrawals are more than X  Balance is less than y  My investment portfolio is up z% since the start of the week

15. 14 Copyright ©2009 Opher Etzion Example 5: Fraud detection

16. 15 Copyright ©2009 Opher Etzion Example 6 – Emergency first responders (presented by Dieter Gawlick from Oracle in the 4 th event processing symposium) Fire Station County Office Hospital Notification Message ABC Chemicals

17. 16 Copyright ©2009 Opher Etzion Example 7 – fairness in trading

18. 17 Copyright ©2009 Opher Etzion Example 8 - Diagnostics: root cause analysis of failure

19. 18 Copyright ©2009 Opher Etzion Example 9 – the cameras in London Car DB Billing Car Theft

20. 19 Copyright ©2009 Opher Etzion Example 10: Presence in social network 5 members are online

21. 20 Copyright ©2009 Opher Etzion Event processing Event Processing is computing that performs operations on events. Common event processing operations include reading, creating, transforming and deleting events. Specific properties of event processing  Abstraction—The operations that form the event processing logic can be separated out from the application logic, allowing them to be modified without having to change the producing and consuming applications.  Decoupling—the events detected and produced by one particular application can be consumed and acted on by completely different applications. There’s no need for producing and consuming applications to be aware of each others’ existence, and they may be distributed anywhere in the world. An event emitted by a single producing application can be acted on by many consuming applications. Conversely you can arrange for an application to consume events produced by many different producing applications.  Real-world focus—event processing frequently deals with events that occur, or could occur, in the real world.

22. 21 Copyright ©2009 Opher Etzion Deterministic and approximate event processing TOLL VILOATOR FRUSTRATED CUSTOMER

23. 22 Copyright ©2009 Opher Etzion Different types of event processing

24. 23 Copyright ©2009 Opher Etzion Main parts of event processing system

25. 24 Copyright ©2009 Opher Etzion Event processing positioning BPM: Can serve as consumer and producer. Some BPM products have ad-hoc EP capabilities. BAM: Typically has built-in limited EP capabilities (mostly aggregations for KPI tracking). Two BAM trends: Moving from KPI to more observation types; Moving from batch observations to some on-line BI: Event-driven BI is still relatively minor, but the area of “operational intelligence” is event-driven and on-line BRMS: Often confusion between the two. Differences: state processing vs. transition history processing. Possible synergies: 1.BRMS as consumer: An action for an event can be rule flow. 2. Rules are used for some EP functionality, e.g. routing 3. BRMS systems can be producers of events 4. Event-driven contexts can serve BRMS 5.Patterns from event processing can be used for cross-state reasoning.

26. 25 Copyright ©2009 Opher Etzion Event processing positioning (cont). Network and Systems Management: Event-driven but concentrated in limited aspects: Event correlation to find the root cause of a problem. Message oriented middleware: Event may be expressed as message – but not every message has event semantics Partial overlap in functionality – especially ESB deals with: validation, enrichment, transformation and routing. Stream computing: Streams are types of data that are not necessarily express events – audio, signal, video… Some overlap on “event stream” --- various positioning throughout the industry.

27. 26 Copyright ©2009 Opher Etzion Request-Response Taken from http://www.eaipatterns.com Based on the Enterprise Integration patterns book by Hohpe and Woolf Synchronous interactions In a synchronous interaction the provider is expected to send a response back fairly promptly. This usually means a few tenths of a second at the longest, though response times of several seconds are sometimes encountered in web applications. The requestor's thread of execution blocks waiting for the response to arrive without doing anything else in the interim / An event is an indication of something that has already happened whereas a request, as its name implies, expresses the requestor’s wish that something specific should happen in the future. As a result we use slightly different terminology for the participants in an interaction involving events. Instead of talking about a service requestor and a service provider, we refer to an event producer and an event consumer.

28. 27 Copyright ©2009 Opher Etzion Point to Point Taken from http://www.eaipatterns.com Based on the Enterprise Integration patterns book by Hohpe and Woolf

29. 28 Copyright ©2009 Opher Etzion Publish-Subscribe Taken from http://www.eaipatterns.com Based on the Enterprise Integration patterns book by Hohpe and Woolf

30. 29 Copyright ©2009 Opher Etzion Principle of decoupling  In a decoupled Event Processing System an event producer does not depend on any particular processing or course of action being taken by any event consumer.  Moreover an event consumer does not depend on any processing performed by the producer other than the production of the event itself.

31. 30 Copyright ©2009 Opher Etzion Push vs. Pull

32. 31 Copyright ©2009 Opher Etzion Event vs. Message There’s one area of possible confusion that it is worth clearing up at this stage, and that is the distinction between an event and a message. Message passing systems are often used to distribute events between event producers and event consumers, and it’s tempting to equate events with the messages used to transmit them. The difference here is that the event is the entity that records information about the event occurrence, whereas the message is the mechanism used to exchange that information. There are messages that don’t contain events, and conversely you can have events that aren’t in the form of messages (for example event records held in an event log).

33. 32 Copyright ©2009 Opher Etzion What Makes EDA Different from Traditional SOA? In Event-Driven Architecture (EDA): 1. Events are always pushed, not pulled. 2. The timing of the event message is determined by the source (event server) not by the event consumers. 3. The event source and the event object never specify what action the consumer will perform — the consumer determines the operation. Not all Event Processing is EDA: 1. Event objects may be transmitted in a request/reply message pair (for example, RPC). 2. Or event objects may be at rest in a database or file (used, for example, in a BI database query). Event-based programming, also called event-driven architecture (EDA) is an architectural style in which one or more components in a software system execute in response to receiving one or more event notifications.

34. 33 Copyright ©2009 Opher Etzion Event processing network

35. 34 Copyright ©2009 Opher Etzion Event Stream An event stream is a set of associated events. It is often a temporally totally ordered set (that is to say that there is a well-defined timestamp-based order to the events in the stream). A stream in which all the events must be of the same type is called a homogeneous event stream; a stream in which the events may be of different types is referred to as a heterogeneous event stream.

36. 35 Copyright ©2009 Opher Etzion Platform Specific Platform Independent Specific Definition Elements Instances Platform Specific Definition Elements Run-time Instance Platform Independent Definition Elements Event Type Building Block Creator for Translated to

37. 36 Copyright ©2009 Opher Etzion Platform Specific Platform Independent Delivery Request 3329 From the Great Flower Shop Delivery Request Event Type (an event schema of product X) Run-time Instance Delivery Request Event Type Event Type Building Block Creator for Translated to

38. 37 Copyright ©2009 Opher Etzion Event Processing Agent Context Event Channel Event Consumer Event Type Event Producer Global State The seven Building blocks

39. 38 Copyright ©2009 Opher Etzion Event Processing Agent FilterTransformDetect Pattern TranslateAggregateSplitCompose EnrichProject Event Processing Agents

40. 39 Copyright ©2009 Opher Etzion Flower Store Van Driver Ranking and Reporting System Bid Request Delivery Bid Assignments, Bid alerts, Assign Alerts Control System GPS Location Location Service Location Driver’s Guild Ranking and reports Delivery confirmation Pick Up confirmation Ranked drivers / automatic assignment Bid System Store Preferences Delivery Request Assignment System Manual Assignment Assignment Assignments, Pick Up Alert Delivery Alert Fast Flower Delivery

41. 40 Copyright ©2009 Opher Etzion Lecture Summary In this lecture we have discussed the following topics: –The notion of event – Event-driven computing – Event processing and its positioning in IT enterprise computing – Event-driven architecture – Model driven approach and major building blocks