Problem Description
This KB article addresses the following NRPE error:
No Output Returned From Plugin
Assumed Knowledge
The following KB article contains an explanation of how NRPE works and may need to be referenced to completely understand the problem and solution that is provided here:
NRPE - Agent and Plugin Explained
Troubleshooting The Error
There are multiple solutions to this problem depending on the cause.
Permissions
The most common solution is to check the permissions on the check_nrpe binary on the Nagios xi server:
ls -la /usr/local/nagios/libexec/check_nrpe
The expected permissions should resemble:
-rwxrwxr-x. 1 nagios nagios 75444 Nov 21 01:38 check_nrpe
If not, change ownership to user/group "nagios" and fix up the permissions:
chown nagios:nagios /usr/local/nagios/libexec/check_nrpe
chmod u+rwx /usr/local/nagios/libexec/check_nrpe
chmod u+rx /usr/local/nagios/libexec/check_nrpe
Missing Plugin
Another cause is a missing plugin file, though, in order to receive this error, you usually have to also be experiencing a secondary configuration issue. In order to resolve issues relating to missing plugins, please refer to the following KB article:
NRPE - Return Code Of 127 Is Out Of Bounds - Plugin May Be Missing
Mismatch of Arguments between Nagios xi and nrpe.cfg
The final cause, and usually the secondary issue for those who found their plugin missing from the expected location, is an argument usage mismatch between the remote host's nrpe.cfg command directive and the arguments passed by Nagios xi through check_nrpe. Please refer to the following KB article to help troubleshoot this:
NRPE - CHECK_NRPE: Received 0 Bytes From Daemon. Check The Remote Server Logs For Error Messages
Final Thoughts
For any support related questions please visit the Nagios Support Forums at: