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Identifying Event Patterns Based On Order of Event Arrival

Purpose:

This application demonstrates how to detect patterns with Siddhi pattern concept. In the sample we capture a pattern where the temperature of a room increases by 5 degrees within 2 minutes

Prerequisites:

  1. Save this sample

Executing the Sample:

  1. Start the Siddhi application by clicking on 'Run'
  2. If the Siddhi application starts successfully, the following messages would be shown on the console
    • PatternMatching.siddhi - Started Successfully!

Notes:

If you edit this application while it's running, stop the application -> Save -> Start.

Testing the Sample:

  1. Simulate single events. For this, click on 'Event Simulator' (double arrows on left tab) -> 'Single Simulation' -> Select 'PatternMatching' as 'Siddhi App Name' -> Select 'RoomTemperatureStream' as 'Stream Name' -> Provide attribute values -> Send
  2. To generate an alert, send one event, followed by another event (within 2 mins) where the temperature of the second event shows an increment by 5 degrees or more (eg. Temperature of event 1 = 17.0, Temperature of event 2 = 30.0). Note that these two events may or may not be consecutive.

Viewing the Results:

See the output on the console. Output will be shown if the second temperature input is incremented by 5 degrees or more.

Note:

Stop this Siddhi application, once you are done with the execution

@App:name("PatternMatching")

@App:description('Identify event patterns based on the order of event arrival')


define stream RoomTemperatureStream(roomNo string, temp double);

@sink(type='log')
define stream RoomTemperatureAlertStream(roomNo string, initialTemp double, finalTemp double);

--Capture a pattern where the temperature of a room increases by 5 degrees within 2 minutes
@info(name='query1')
from every( e1 = RoomTemperatureStream ) -> e2 = RoomTemperatureStream [e1.roomNo == roomNo and (e1.temp + 5.0) <= temp]
    within 2 min
select e1.roomNo, e1.temp as initialTemp, e2.temp as finalTemp
insert into RoomTemperatureAlertStream;