I successfully installed and connected 2 slaves to my master server. The problem is, neither are sending out alerts and the Postfix logs on both are empty. The "Run On" option is also set to "Slave" on the Master server. What could I possibly miss?
sudo su – nagios nlcat |grep NOTIF
would give me this:
Thu Apr 14 13:43:43 2016: wproc: NOTIFY job 114 from worker Core Worker 9378 is a non-check helper but exited with return code 255
What was missing was installing the Mail package.
Also if you're using Ubuntu dont forget to alter the default sending script from /usr/bin/Mail to /usr/bin/mail.