IBM BJ0NJML Integration Guide - Page 174

Cron Tasks Cron Tasks The interface table polling process uses a single default cron task called IFACETABLECONSUMER. This cron task reads all messages from all interface tables for all external systems that write to the tables. Configuring Cron Tasks For improved performance on single-server and multi-server environments, you can configure multithreaded interface table polling by defining multiple instances of the IFACETABLECONSUMER cron task with different property values. Multithreaded polling is useful in a clustered configuration, because different threads can run on different servers, thereby balancing the load. To designate an instance of the cron task named instance1 to run on a specific application server: T In the Cron Task Setup application, set the TARGETENABLED property to 1. T In the application server1 setup, set -DIFACETBCONSUMER.instance1=1 When you implement multiple cron tasks, you also must implement mutually exclusive selectors to avoid processing a message more than once. For more information about cron tasks, refer to the System Administrator Guide, and the online help for the Cron Task Setup application. Selectors You use a selector to add a WHERE clause to a cron task. If you define multiple instances of the cron task, you must define selectors, so that each instance reads mutually exclusive interface table rows. For example, if the system exchanges data with two external systems, the first thread might poll one system and the second thread might poll the second system. Defining Selectors You define selectors by assigning values to the EXTSYSNAME (external system) and ENTERPRISESERVICE (enterprise service) parameters in the Cron Task Setup application. You can add an IN clause to a selector by entering a pipedelimited set of values. To direct a cron task to select only purchase order records for system EXTSYS1 from the queue tables: T Set ENTERPRISESERVICE=MXPOInterface T Set EXTSYSNAME=EXTSYS1 160 Integration Guide