Nagios Support Forum

Hello,

I've got two questions about the config-parameters in the nagios.cfg-file of nagios 4.

max_concurrent_checks=600
host_check_timeout=30
service_check_timeout=60

1.) When does start nagios-core the counting of the timeout for an service-check? Does it start the timeout-period when the service-check has been inserted in the service-queue already (for instance 5000 checks exists, but only 600 are parellel allowed) or start it the timeout-period not until the service-check is executing?
2.) For the Host checks I miss a similar parameter "max_concurrent_checks=600" in the nagios.cfg. Are they also limited by the max_concurrent_checks-parameter?

Regards
Schmatte

Hello, @Schmatte. The host_check_timeout count starts when nagios begins executing a host check-plugin. It doesn't depend on max_concurrent_checks, although if the number of max_concurrent_checks has been reached Nagios will pause executing other checks.

So the timeout starts when Nagios actually executes the plugin. If the max concurrent number has been reached, Nagios will not execute any other checks until the previous ones are completed.
You're right, looks like it is only possible to limit max concurrent service checks but not host checks.

This option allows you to specify the maximum number of service checks that can be run in parallel at any given time.

https://assets.nagios.com/downloads/nag ... gmain.html
Let me know if you have any other questions.