script to check whether the server is alive

[Joyce Suganthy]

Hi ,

Do any one have any scripts that check whether the server is alive using the ping command?

Regards
Joyce

[Lee Tae-kyung]

It's simple^^

-----------------------------------
while true
do
echo "******************************"
echo " Servers Monitoring "
echo "******************************"
ping Svr1 &
ping Svr2 &
ping Svr3 &
sleep 10
echo " "
done
-------------------------------------

Have a nice day^^

From Korea.

[Mark Grant]

Actually, it's a bit more complicated than that.

You need to give "ping" a timeout. which you do with "ping -n 1". Sadly, the exit status returned by ping is not usable either so you need to check the output to see if the machine was "pingable".

Something like

#!/usr/bin/sh

ping -n 1 | grep "0 packets" && {
echo "Oh dear the machine seems in trouble"
}

[Elmar P. Kolkman]

And there is more... A server can respond to ping quite nicely, but that doesn't mean its alive. It only means its network interface is alive.

What we do is first ping the server to see if we can reach it over the network, by pinging with 3 packets and see if at least one got a response. (Some servers are connected over lines that are not up all the time, so it takes time for the network link to work, resulting in some packet loss...)
Then try to auto-login with things like ftp, remsh or ssh, depending on what you have available. And then do some sanity checks on the remote machine, like looking for /sbin/rc commands still running (meaning it is still booting), etc.

I'm afraid that I can't distribute our script, which is highly configurable on the check part, but does it like mentioned above.

[Mark Grant]

Elmar,

Sounds like you might benefit for developing that into a client-server architecure. Then simply ask the client if it's OK :)

[MarkSyder]

I think Big Brother will meet your requirements.

Sorry, I'm having a busy day and haven't got time to dig out the web address for you, but if you go on to Google and type big brother hp ux you should be pointed in the right direction.

Mark Syder (like the drink but spelt different)

[Elmar P. Kolkman]

Mark, problem with client-server is that the server needs to be up to run. Now I can check how much of a server is running. Which is info I need when I run the script.
And now it is in shell scripting, which is easier to maintain for other people (I wrote the script etc. 6 years back, when perl wasn't really an option and we only had 2 people who could read and write C-programs).

[Mark Greene_1]

You also first need to ping the gateway for the server running the script. If your system that's doing the checking has been disconnected from the network, everything you check will appear to be down.

mark

[Ross Minkov]

http://www.bb4.com

Big Brother monitors System and Network-delivered services for availability. Your current network status is displayed on a color-coded web page in near-real time. When problems are detected, you're immediately notified by e-mail, pager, or text messaging.