DURATION Clause and Non-Event Detection

21-4 Oracle Complex Event Processing Developers Guide wlevs:listener bean class=com.bea.wlevs.example.helloworld.HelloWorldBean wlevs:listener wlevs:adapter beans 5. Optionally, configure the channel downstream from the input adapter helloworldInputChannel to configure an application timestamp based on an appropriate event property as Example 21–4 shows. For simple failover, you can use system timestamps because events are not correlated between servers. However, it is possible that slightly different results might be output from the buffer if application timestamps are not used. In this example, event property arrivalTime is used. The wlevs:expression should be set to this event property. Example 21–4 Application Timestamp Configuration ... wlevs:channel id=helloworldInputChannel event-type=HelloWorldEvent wlevs:listener ref=helloworldProcessor wlevs:source ref=myHaInputAdapter wlevs:application-timestamped wlevs:expressionarrivalTimewlevs:expression wlevs:application-timestamped wlevs:channel ... 6. Configure the Oracle CEP high availability buffering output adapter. Set the instance property windowLength to zero 0 as Example 21–5 shows. Example 21–5 Configuring windowLength in the Buffering Output Adapter ... wlevs:adapter id=myHaSlidingWindowAdapter provider=ha-buffering wlevs:listener bean class=com.bea.wlevs.example.helloworld.HelloWorldBean wlevs:listener wlevs:instance-property name=windowLength value=0 wlevs:adapter ... For more information, see Section 21.2.2.1, Buffering Output Adapter EPN Assembly File Configuration . 7. Optionally, configure the component configuration file to include the Oracle CEP high availability buffering output adapter as Example 21–6 shows. Example 21–6 Simple Failover Component Configuration File With High Availability Adapters ?xml version=1.0 encoding=UTF-8? wlevs:config xmlns:wlevs=http:www.bea.comnswlevsconfigapplication xmlns:ha=http:www.oracle.comnscepconfigcluster processor namehelloworldProcessorname rules query id=helloworldRule [CDATA[ select from helloworldInputChannel [Now] ]] query