you are completely missing my point.. Ping (icmp) is controlled by the
OS. If your OS is down (i.e. never booted) icmp will not come back, and
neither will your service. But however if the host (operating system)
booted but for some reason services were never engaged then the problem
is completely different. Simply stating that all nagios cares about is
services and that if you have no available services (for which you
monitor) then the box is down, then what is the point in the host check
to begin with? Lets remove that completely and make people add their own
icmp service if they want to check that. I hope you see my point. I
would think accuracy in showing what is really the happening (i.e. not
saying host down when the host is really up) would be very important. If
you do not agree, that is fine.. Simply a suggestion.
Kenneth.ray wrote:
> 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 wha
...[email truncated]...
This post was automatically imported from historical nagios-devel mailing list archives
Original poster: sybase@vantageltd.com