# Setting Update Intervals

The update interval for an interoperation specifies how frequently RIB will poll the interoperating repository to determine if its collection of objects from your primary class has changed. If so, RIB will update your catalog with the appropriate changes.

To change an interoperation update interval, select (left-click) the interoperation. You can select multiple interoperations by using CTRL+click or shift+click. Now right-click the selection and a popup menu will apper. Then choose "Set update interval", and choose a new interval. Setting the update interval to a larger value decreases network traffic between your repository and the remote repository. Setting the update interval to a smaller value generates more network traffic, but ensures that changes to the remote repository appear in your catalog sooner. Use a larger value if you expect the objects in the remote repository to change infrequently.

In order for RIB to be able to automatically perform updates, you must have set up a scheduled job on the machine where RIB is installed. On UNIX machines this is done using the "cron" system utility. Assuming that the RIB web application is installed in the directory /usr/local/jakarta-tomcat-5.5.4/webapps/rib3app, simply add a line such as the following to a crontab:

    0,15,30,45 * * * * java -cp /usr/local/jakarta-tomcat-5.5.4/webapps/rib3app/bin:
                                /usr/local/jakarta-tomcat-5.5.4/webapps/rib3app/WEB-INF/classes UpdateAllInterops

This will cause RIB to check the update intervals every 15 minutes.