Monitor Nagios client services only when NRPE on client is up - nagios

Question

Is there any way to achieve below scenario in Nagios using NRPE?
Nagios box will first check if NRPE on client box is up and if yes it wil check on other services configured for that client. If NRPE is down on client, it will throw notification for NRPE and will stop checking rest of the services configured for that client box until NRPE comes up.

Answer 1

This setting is what are you looking for. Look at your nagios.cfg
# DISABLE SERVICE CHECKS WHEN HOST DOWN
# This option will disable all service checks if the host is not in an UP state
#
# While desirable in some environments, enabling this value can distort report
# values as the expected quantity of checks will not have been performed
host_down_disable_service_checks=1
Check your hosts status via check_nrpe. Create new command in your config, if you don't have it:
define command{
command_name check-host-alive-nrpe
command_line $USER1$/check_nrpe -H $HOSTADDRESS$
}
Now, use this command in your host definition, something like that:
define host {
host_name your_server
address your_server
use generic-host
check_command check-host-alive-nrpe
}
When the NRPE on remote host stop responding due some problems, this host will be in CRITICAL state and remote check for services will be temporary disabled.
After you configure this don't forget restart your Nagios service.
PS: This setting works only with Nagios 4+

Answer 2

I achieved this via service dependency where all nrpe checks depend on nrpe service availability check.
define servicedependency{
hostgroup linux-servers
# host_name xyz.example.com
service_description check_nrpe_alive
dependent_service_description check_disk,check_mem,chech_load,check_time,check_disk
execution_failure_criteria w,c,u
notification_failure_criteria u,w,c,o
}
Below is check_nrpe_alive check command definition.
define command{
command_name check_nrpe_alive
command_line $USER1$/check_nrpe -H $HOSTADDRESS$
}
Also needed to set soft_service_dependencies=1 in nagios.cfg
# SOFT STATE DEPENDENCIES
# This option determines whether or not Nagios will use soft state
# information when checking host and service dependencies. Normally
# Nagios will only use the latest hard host or service state when
# checking dependencies. If you want it to use the latest state (regardless
# of whether its a soft or hard state type), enable this option.
# Values:
# 0 = Don't use soft state dependencies (default)
# 1 = Use soft state dependencies
# Changing fpr service dependency
#soft_state_dependencies=0
soft_state_dependencies=1
When nrpe service on client is in CRITCAL state Nagios will only send out notification for check_nrpe_alive but not any dependent service checks. This is tested on Nagios core 4.4.6