Splunk add-on and app logs

Hi, I have a setup in which the deployment server pushes the Splunk_TA_NIX add-on, Splunk unix app and JMX add-on to the deployment client, but the data is not flowing in. 1) Which logs should I check? Do the apps/add-ons have a separate log file, or are they included in the splunkd.log? 2) Which terms should I use to filter out the app and add-on logs from the splunkd.log? Thanks, Deepak