[Nagios-devel] Re: Percieved problem with host checks

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[Nagios-devel] Re: Percieved problem with host checks

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Dear Sir,
thank you for your email however, I do believe
actually your test is flawed. you are under the premise that
the host is the important piece to your network. but actually
the service running on the host is the most important issue.
what good is a host that has no services available,
ping is a really basic service and only helps in determing
that the network interface is accessable. In some cases
it is quite possible for the ping to work and the box be down.
If this is a real problem for you, add a seperate service called
"alive " "pingable" or something related, and run the ping as a
service ,this will change your host to be "up" even if no services
are available from it. But Again, in my own humble opinion. this
proves nothing other than, you can ping the interface, your not
even pinging the server, your pinging the network card which
is hooked to the box.

think of the logic in this sense, if a host is not a actual entity
but really a container/conduit to your services. so logic would
dictate that regardless if the entity for serving your services is
available, the real issue is not the entity but the service provided
by the container. IMHO you can actually replace the word "host" with
container and the logic of netsaint still holds up. Netsaint is service based

not server based. and uses the logic of, "what good is a host without
something running on it?" and though ping is a good conduit. for determining
if the network card is accessable from the network for a
particular server, the only thing this proves is that the network card is
accessable by the network. I personally have had a server that was pingable
but no services were available because the system was pegged. the network
interface was actually the only thing responding on one system, and after
being
physically infront of the system i could see why.
So i would have to strongly disagree with you on the statement "the logic is
flawed"
using your same situation
you have a particular problem which brings down the box and causes a reboot.
the service that you run on this box never comes up. its the only one you are

monitoring, but lets say the host reports as up( cause you set up another
service called "alive"
like in my suggestion), because you can ping it. lets say
that this system is your ftp server, ftp is not working, you try telnetting
and still
that is not working either.
'you ping
you ping
you ping
nice!!! is the box up? are the services available? can you TRUELY say
the container is in a state that would allow the service to pass through?
are the people accessing this ftp server able to do so? nope guess not, so
for
all intents and purposes, your host is totally unusable. so is it up? that
is the
logic of netsaint. the host is not the thing netsaint/nagios cares about, it
is only a conduit
to the service you need. a toolbox to hold your tools, if the toolbox is
empty can you
work? the fact that the toolbox exists IS important, cause that is where you
keep your tools and without your tools nothing gets done. can you use your
toolbox
as a tool? sure, but only if you redefine what a tool is.. there is the logic
you seek, not
flawed but perfectly logical.
if you want to emphasize your host as important all you need do is create a
service called "alive"
give it the same parameters as your host, and you host will "magically" be
considered up.

hope this helps in understanding the logic.
Ken

>
> --__--__--
>
> Message: 1
> Date: Sun, 15 Sep 2002 02:40:41 -0500
> From: SyBase
> To: Russell Scibetti
> CC: John Fox , nagios-users@lists.sourceforge.net,
> nagios-devel@lists.sourceforge.net
> Subject: Re: [Nagios-devel] Re: [Nagios-users] Perceived problem with host
> checks
>
> This may be by design, but IMHO this logic is flawed. Say you have a
> problem with a particular host service that first caused the box to
> reboot (setting host state to down) then when the box comes b

...[email truncated]...


This post was automatically imported from historical nagios-devel mailing list archives
Original poster: kenneth.ray@travelersla.com
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