It is possible to set logger levels temporarily using the logForDev.zul page in the UI, however these changes are not persisted across service restarts. At times it is beneficial to set DEBUG level permanently on loggers in the Core service due to the issue you are troubleshooting being intermittent and not being sure if the service will be restarted between occurrences.
Locate the logger name that you are wanting to enable permanent DEBUG level for. Typically you would find this in https://<hostname>/ConnectAll/logForDev.zul
In this example, we will use the CherwellRequestHelper logger as shown in this screenshot:
Once you have the logger name, edit your log4j.xml file in <CONNECTALL_HOME>/Core/conf
Scroll down to the Loggers section and add a new line using the pattern shown below:
<Logger name="logger_name" level="DEBUG"/>
In our example the line will look like this:
<Logger name="com.go2group.connectall.adapter.cherwell.CherwellRequestHelper" level="DEBUG"/>
Save the file.
Restart the Core service.
After this, the DEBUG level will persist across service restarts.