RE: [Nagios-users] Setting up service dependencies

[Jeff B. <jbo...@ya...>]

yeah, I'm willing to deal with the fact that the host may not be really
down if I'm checking HTTP.
 
Your example is similar to what I tried. But almost all my services use
hostgroup_name rather than host_name to keep things manageable.
Otherwise I would have over 500 service objects to manage.
servicedependency doesn't seem to work right when you substitute
hostgroup_name for host_name like it works for all other object
definitions. I would have to create thousands of service dependecies if
I were to do everything on a host basis rather than hostgroup. Oh well,
but here's a vote for XML config files which would make automatic
generation of these files easier. 
 
Jeff

-----Original Message-----
From: Carroll, Jim P [Contractor] [mailto:jca...@sp...] 
Sent: Thursday, January 09, 2003 7:29 AM
To: 'Jeff Boulter'; Nag...@li...
Subject: RE: [Nagios-users] Setting up service dependencies


It's not A Bad Thing per se; given the example of a host behind a
firewall with a hole at port 80 poked through it, it would certainly
have merit.  But in the case where your webserver fails but, say, sshd
is still up, can the host be said to be down?
 
Just to say that I gave you a servicedependency example, here it is:
 
define service{
        host_name                       itdmll01
        use                             icmp
        service_description             NRPE check
        contact_groups                  linux-admins
        check_command                   check_nrpe!check_nrpe_status
        }
 
define service{
        host_name                       itdmll01
        use                             icmp
        service_description             Total Users
        contact_groups                  linux-admins
        check_command                   check_nrpe!check_users
        }
define servicedependency{
        dependent_host_name             itdmll01
        dependent_service_description   Total Users
        host_name                       itdmll01
        service_description             NRPE check
        execution_failure_criteria      w,u,c
        notification_failure_criteria   w,u,c
        }

Explanation:  "NRPE check" is the basic 'is NRPE up' check.  "Total
Users" actually kicks off a plugin on the remote host.  "Total Users" is
dependent on "NRPE check".  If "Total Users" fails, it checks to make
sure that "NRPE check" is up/down.  If the latter is down, that's all I
get alerted on.  If it's still up, then I get alerted on the former.
 
Does this help?
 
jc
 

-----Original Message-----
From: Jeff Boulter [mailto:jbo...@ya...]
Sent: Wednesday, January 08, 2003 7:53 PM
To: Nag...@li...
Subject: RE: [Nagios-users] Setting up service dependencies


I think I found a workaround for this. For some servers, like webservers
most of the services are some form of HTTP request, so I changed the
check_command on the host to do a simple http request. If that fails,
then the host is considered 'down' rather than just using the standard
ping check. If this is 'bad' for some reason, please let me know.
 
second question: is it possible to pass arbitrary ssh parameters to
check_ssh, like "-1" for ssh v1? Doesn't appear so, but maybe there's a
trick?
 
Jeff  

-----Original Message-----
From: Jeff Boulter [mailto:jbo...@ya...] 
Sent: Wednesday, January 08, 2003 10:12 AM
To: 'Nag...@li...'
Subject: RE: [Nagios-users] Setting up service dependencies


I've looked at the examples that come with nagios and they don't seem to
address the problem of using hostgroups versus hosts. I'm not using
NPRE, but if you have examples using hostgroups, I'd love to see them.
 
Jeff

-----Original Message-----
From: nag...@li...
[mailto:nag...@li...] On Behalf Of Carroll,
Jim P [Contractor]
Sent: Tuesday, January 07, 2003 1:47 PM
To: 'Jeff Boulter'; Nag...@li...
Subject: RE: [Nagios-users] Setting up service dependencies


That's different.  You'll want to set up a service dependency, of
course.
 
Er... do you absolutely need to check for static HTML?  I mean, if the
PHP fails because the webserver is down....  Oh, unless you just want to
be informed that there's a PHP problem but that the server itself it
still up.  Okay, I can see that.
 
I've set up various NRPE dependencies at our site, so if you need a
trivial example, I can post one to the list.  Let me know.
 
jc

-----Original Message-----
From: Jeff Boulter [mailto:jbo...@ya...]
Sent: Tuesday, January 07, 2003 1:05 PM
To: Nag...@li...
Subject: RE: [Nagios-users] Setting up service dependencies


That's good to know. I still have this issue though because I have some
tests that aren't going work if simpler tests fail. For example, a
simple test to see if a webserver can serve a static HTML can fail, and
if that's the case then checking to see if the webserver will return a
PHP page is obviously not going to work. 
 
Jeff

-----Original Message-----
From: Carroll, Jim P [Contractor] [mailto:jca...@sp...] 
Sent: Tuesday, January 07, 2003 10:41 AM
To: Jeff Boulter; Nag...@li...
Subject: RE: [Nagios-users] Setting up service dependencies


I'm not sure why you're taking this approach.  Out of the box, Nagios
will behave as you wish it to.
 
If a service check fails, then a host check is made.  If the host check
fails, it's flagged as down and, depending on your particular
configuration, you'll receive the notification for the host being down,
not for the N services you're monitoring on that host.  If the host
check passes, then you'll get an alert on the service.
 
jc

-----Original Message-----
From: Jeff Boulter [mailto:jbo...@ya...]
Sent: Monday, January 06, 2003 6:37 PM
To: Nag...@li...
Subject: [Nagios-users] Setting up service dependencies




Hello all, 

I'm trying to set up service dependencies in Nagios. For example, I
don't want alerts about an HTTP service being down on a host if the host
isn't pingable.

So far, the only way I've found to do this is to set it up for each host
individually. That would be difficult with the hundreds of hosts that my
nagios is currently monitoring.

I tried creating a servicedependency object with a hostgroup_name and a
dependent_hostgroup_name. This seems to make each host in hostgroup_name
dependent on EVERY host in dependent_hostgroup_name. For example, if my
hostgroup has 7 hosts in it, it seems it's making each of those 7 hosts
dependent on each other, making 7x7=49 dependencies. (Stragely, Nagios
reports 98 dependencies. Why 2x?) 

Any suggestions on how to make a service dependencies local to each host
and not a group of hosts without lots and lots of dependency objects?

Jeff