TroubleshootingΒΆ

If you cannot access the Nagios web UI, use the following troubleshooting tips.

  1. Verify that the StackLight Collector is able to connect to the Nagios VIP address on port 80.

  2. Verify that the Nagios configuration is valid:

    [root@node-13 ~]# nagios3 -v /etc/nagios3/nagios.cfg

   [snip]

Total Warnings: 0
Total Errors:   0
No serious problems were detected during the pre-flight check.

  1. Verify that the Nagios server is up and running:

    [root@node-13 ~]# crm resource status nagios3
resource nagios3 is NOT running

  2. If Nagios is not running, start it:

    [root@node-13 ~]# crm resource start nagios3

  3. Verify that Apache is up and running:

    [root@node-13 ~]# crm resource status apache2-nagios

  4. If Apache is not running, start it:

    [root@node-13 ~]# crm resource start apache2-nagios

  5. Look for errors in the Nagios /var/nagios/nagios.log log file:

  6. Look for errors in the Apache log files:

    • /var/log/apache2/nagios_error.log
    • /var/log/apache2/nagios_wsgi_access.log
    • /var/log/apache2/nagios_wsgi_error.log

Nagios may report a host or service state as UNKNOWN, for example:

  • ‘UNKNOWN: No datapoint have been received ever’
  • ‘UNKNOWN: No datapoint have been received over the last X seconds’

Both cases indicate that Nagios does not receive regular passive checks from the StackLight Collector. This may be due to different issues, for example:

  • The ‘hekad’ process fails to communicate with Nagios
  • The ‘collectd’ and/or ‘hekad’ process have crashed
  • One or several alarm rules are misconfigured

For solutions, see the Troubleshooting section in the StackLight Collector plugin documentation.