Nagios Host Check Behaviour

[Erik Sejr]

Thanks Daniel - on demand checks was exactly what I was looking for.

Regards,
Erik

On 06/23/2011 05:20 PM, Daniel Tuecks wrote:
> Hello,
> 
> sounds like you want 'on demand host checks'.
> 
> "Regularly scheduled host checks are optional. If you set the
> check_interval option in your host definition to zero (0), Nagios will
> not perform checks of the hosts on a regular basis. It will, however,
> still perform on-demand checks of the host as needed for other parts
> of the monitoring logic.
> 
> On-demand checks are made when a service associated with the host
> changes state because Nagios needs to know whether the host has also
> changed state. Services that change state are often an indicator that
> the host may have also changed state. For example, if Nagios detects
> that the HTTP service associated with a host just changed from a
> CRITICAL to an OK state, it may indicate that the host just recovered
> from a reboot and is now back up and running. "
> 
> This is quoted from the official Nagios Documenation:
> http://nagios.sourceforge.net/docs/3_0/hostchecks.html
> 
> 
> Regards
> Daniel
> 
> 2011/6/23 Erik Sejr <eriks at ssimicro.com>:
>> Hi,
>> I have a question for the list regarding the behaviour of host checks in
>> Nagios. My understanding was that host checks only took place if a
>> service changed state, otherwise the state of the host was assumed based
>> on the state of the services that host provides.
>>
>> We have a number of hosts, each with 1 or more passive services. Passive
>> service checks arrive every five minutes with a freshness threshold set
>> at 6 minutes. I am trying to get the behaviour described above - I only
>> want nagios to perform a host check if a service changes state (from up
>> to down). Otherwise, if all host services are OK I want nagios to assume
>> the host the services are running on is also OK.
>>
>> I cannot seem to get it to do this, I can only get one extreme or the other:
>>
>> 1. Nagios checks the hosts, every 5 minutes regardless of the state of
>> the services. I have confirmed this though a TCP dump on the server. The
>> pings to the host go out (and come back) every 5 minutes.
>>
>> OR
>>
>> 2. Nagios never checks the hosts and they all show as PENDING for ever
>> and ever.
>>
>> If The host template is configured as follows I get scenario #1
>>
>> define host{
>> name                           remote-host
>> hostgroups                     NBDC
>> register                       0
>> max_check_attempts             5
>> notification_interval          5
>> notification_period            24x7
>> notification_options           d,r
>> contact_groups                 regular_contacts
>> check_command                  check-host-alive
>> }
>>
>> If The host template is configured as follows I get scenario #2
>>
>> define host{
>> name                           remote-host
>> hostgroups                     NBDC
>> register                       0
>> max_check_attempts             5
>> notification_interval          5
>> notification_period            24x7
>> notification_options           d,r
>> contact_groups                 regular_contacts
>> }
>>
>> The difference is the insertion or lack of the check_command.
>>
>> Hosts are defined to use the template in a basic manner:
>>
>> define host{
>> host_name                       rtr01
>> alias                           Router 01
>> address                         rtr01.domain.com
>> parents                         upstream-rtr01,upstream-rtr02
>> use                             remote-host
>> }
>>
>> define host{
>> host_name                       dhcp1
>> alias                           DHCP Network Gateway
>> address                         dhcp1.domain.com
>> parents                         rtr01
>> use                             remote-host
>> }
>>
>> Any thoughts? Am I missing something in the config?
>>
>> ------------------------------------------------------------------------------
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> 
> ------------------------------------------------------------------------------
> All the data continuously generated in your IT infrastructure contains a 
> definitive record of customers, application performance, security 
> threats, fraudulent activity and more. Splunk takes this data and makes 
> sense of it. Business sense. IT sense. Common sense.. 
> http://p.sf.net/sfu/splunk-d2d-c1
> _______________________________________________
> Nagios-users mailing list
> Nagios-users at lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/nagios-users
> ::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. 
> ::: Messages without supporting info will risk being sent to /dev/null
> 


------------------------------------------------------------------------------
All the data continuously generated in your IT infrastructure contains a 
definitive record of customers, application performance, security 
threats, fraudulent activity and more. Splunk takes this data and makes 
sense of it. Business sense. IT sense. Common sense.. 
http://p.sf.net/sfu/splunk-d2d-c1
_______________________________________________
Nagios-users mailing list
Nagios-users at lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/nagios-users
::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. 
::: Messages without supporting info will risk being sent to /dev/null