How to Configure a System-Timestamped Channel Using Oracle CEP IDE for Eclipse

Configuring Channels 9-9 channel 9. Optionally, override the default channel configuration by adding additional channel child elements: ■ Add a max-threads child element to specify the maximum number of threads that Oracle CEP server uses to process events for this channel. Setting this value has no effect when max-size is 0. The default value is 0. channel namepriceStreamname max-threads2size channel When set to 0, the channel acts as a pass-through. When max-threads 0, the channel acts as classic blocking queue, where upstream components are producers of events and the downstream components are the consumers of events. The queue size is defined by the configuration max-size. There will be up to max-threads number of threads consuming events from the queue. ■ Add a max-size child element to specify the maximum size of the channel. Zero-size channels synchronously pass-through events. Non-zero size channels process events asynchronously, buffering events by the requested size. The default value is 0. channel namepriceStreamname max-size10000size channel ■ Add a heartbeat child element to specify the number of nanoseconds a channel can be idle before Oracle CEP generates a heartbeat event to advance time. The heartbeat child element applies to system-timestamped relations or streams only when no events arrive in the event channels that are feeding the processors and the processor has been configured with a statement that includes some temporal operator, such as a time-based window or a pattern matching with duration. channel nameMatchOutputChannelname heartbeat10000heartbeat channel ■ Add a selector child element to specify which up-stream Oracle CQL processor queries are permitted to output their results to the channel. You may configure a channel element with a selector before creating the queries in the upstream processor. In this case, you must specify query names that match the names in the selector. For more information, Section 9.1.5, Controlling Which Queries Output to a Downstream Channel: selector . Caution: Identifiers and names in XML files are case sensitive. Be sure to specify the same case when referencing the components identifier in the EPN assembly file. 9-10 Oracle Complex Event Processing Developers Guide

10. Select File Save.

The EPN Editor adds a configuration badge to the channel as Figure 9–2 shows. For more information, see Section 6.2.7, Configuration Badging . Figure 9–2 Channel With Configuration Badge

9.2.2 How to Configure an Application-Timestamped Channel Using Oracle CEP IDE for Eclipse

This section describes how to create an application-timestamped channel. The most efficient and least error-prone way to create and edit a channel configuration in the default component configuration file is to use the Oracle CEP IDE for Eclipse. Optionally, you can create a channel configuration file manually see Section 9.2.3, How to Create a Channel Component Configuration File Manually . For more information, see: ■ Section 9.1.4, Application-Timestamped Channels ■ Chapter 6, Oracle CEP IDE for Eclipse and the Event Processing Network To configure a channel using Oracle CEP IDE for Eclipse: 1. Use Oracle CEP IDE for Eclipse to create a channel. See Section 6.4.1.1, How to Create a Basic Node .

2. Optionally, override the default channel assembly file configuration by adding

additional wlevs:channel attributes and child elements:

a. Right-click the channel node and select Go To Assembly Source.