False alarm

[Jason.chua]

Hi support

We receive critical email alerts from nagios xi server informing that few of hosts are down. After that, we check on servers and found out that it is false alarm. Our network is also ok since there are no downtime recorded on system logs. Please advise.

FYI, we are using Nagios XI 2014R2.6 and it is running on CentOS linux OS version 6.6 64 bit. If you need any logs and other information from nagios server. Please let me know.

Thanks for help in advance.

[tmcdonald]

False alarms could result from a number of things:

• Intermittent network issues
• Plugins timing out
• Too low of a max check attempts value
• Misconfigured plugins/commands/thresholds

Without knowing more about the host, the command that is running to check it, and the output of that check, it is almost impossible to say what caused it.

[gormank]

Have a look at the check settings tab on the host/service and look at the retry interval and max check attempts. Also check the alert settings tab and the first notification delay setting.
Adding 5 retries at 1 minute intervals plus a 5 minute notification delay should add up to a 10 minute delay total. This gives the system some time to clear alerts of short duration, and can quiet things down a lot.
I put these and other values in templates so I can tune them in less places.

[rkennedy]

Thanks @gormank!

@Jason.chua - let us know if you have any further questions.