Source Event Identity Externally Understand the Importance of Event Ordering

21 Configuring High Availability 21-1 21 Configuring High Availability This chapter describes how to configure high availability for your Oracle CEP application depending on the quality of service you require, including: ■ Section 21.1, Configuring High Availability Quality of Service ■ Section 21.2, Configuring High Availability Adapters For more information on high availability options, see Chapter 20, Understanding High Availability .

21.1 Configuring High Availability Quality of Service

You configure Oracle CEP high availability quality of service in the EPN assembly file and component configuration files. For general information about these configuration files, see: ■ Section 1.1.4, EPN Assembly File ■ Section 1.1.5, Component Configuration Files This section describes: ■ Section 21.1.1, How to Configure Simple Failover ■ Section 21.1.2, How to Configure Simple Failover With Buffering ■ Section 21.1.3, How to Configure Light-Weight Queue Trimming ■ Section 21.1.4, How to Configure Precise Recovery With JMS For more information on configuring an Oracle CEP high availability application for scalability, see Section 20.1.4, High Availability and Scalability .

21.1.1 How to Configure Simple Failover

You configure simple failover using the Oracle CEP buffering output adapter with a sliding window size of zero 0. This procedure starts with the example EPN that Figure 21–1 shows and adds the required components to configure it for simple failover. Example 21–1 shows the corresponding EPN assembly file and Example 21–2 shows the corresponding component configuration file. Note: After making any Oracle CEP high availability configuration changes, you must redeploy your Oracle CEP application. See Section 24.5, Deploying Oracle CEP Applications . 21-2 Oracle Complex Event Processing Developers Guide For more information about this Oracle CEP high availability quality of service, see Section 20.2.1, Simple Failover . Figure 21–1 Simple Failover EPN Example 21–1 Simple Failover EPN Assembly File ?xml version=1.0 encoding=UTF-8? beans ... wlevs:event-type-repository wlevs:event-type type-name=HelloWorldEvent wlevs:classcom.bea.wlevs.event.example.helloworld.HelloWorldEventwlevs:class wlevs:event-type wlevs:event-type-repository wlevs:adapter id=helloworldAdapter class=com.bea.wlevs.adapter.example.helloworld.HelloWorldAdapter wlevs:instance-property name=message value=HelloWorld - the current time is: wlevs:adapter wlevs:channel id=helloworldInputChannel event-type=HelloWorldEvent wlevs:listener ref=helloworldProcessor wlevs:source ref=helloworldAdapter wlevs:channel wlevs:processor id=helloworldProcessor wlevs:channel id=helloworldOutputChannel event-type=HelloWorldEvent advertise=true wlevs:listener bean class=com.bea.wlevs.example.helloworld.HelloWorldBean wlevs:listener wlevs:source ref=helloworldProcessor wlevs:channel beans Example 21–2 Simple Failover Component Configuration Assembly File ?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 rules processor wlevs:config To configure simple failover: 1. Create a multi-server domain using Oracle Coherence. For more information, see: