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A_124585's avatar
A_124585
Icon for Nimbostratus rankNimbostratus
Dec 05, 2013

Custom monitoring of linux server from GTM

I want my GTM to be able monitor the availability of the application process on an external Linux server - hence I want a custom monitor (not just a TCP half open).

 

I am rather a newbie - so I apologise in advance if these are obvious questions.....

 

Questions:

 

  1. Does the GTM already have a SSH client already on it or not. If it does, do I need to do anything to enable it?

     

  2. Any recommendations on use of the script vs external monitor to create an SSH connection to a server and perform a simple query?

     

  3. I probably need to poll my server every 10 seconds, and not sure I want to have to re-establish the SSH tunnel every time. Has any one an experience of keeping tunnel open with one of these monitors?

     

Thanks

 

Anne

 

application delivery
BIG-IP DNS
big-ip gtm
design
gtm
monitoring
ssh

3 Replies

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  • Jason_40733's avatar
    Jason_40733
    Icon for Cirrocumulus rankCirrocumulus
    Dec 05, 2013
    1: The GTM is a bigip and runs on a *nix based OS. SSH is included. Some more information might help in determining the rest of the answers. Do you have LTMs in the environment? Ideally the LTMs would monitor the server ( or even run customer monitors ) and report the status upstream to the GTM(s). An external monitor in bigip is typically a created script run from the *nix side of the OS. Someone correct me if I'm wrong, but that's my understanding. This can be a shell script, perl, compiled binary that works on the bigip operating system, etc... The process you want to check for, is it a web service or anything that has a port that can be queried by some means to gain an answer? If so, I'd highly recommend using that type of monitor versus logging into the system using ssh and checking for a process. Example: Instead of ssh'ing and checking for an ldap process on a server, use a built-in ldap query monitor from an LTM/GTM or use an LDAP query external monitor script that performs an ldap query to the server.
  • A_124585's avatar
    A_124585
    Icon for Nimbostratus rankNimbostratus
    Dec 05, 2013
    Thanks Jason, In answer to your qs: There are no LTMs, and its VPN server that I need to check the health of - so there aren't any of the standard monitors I can use.
  • Kevin_K_51432's avatar
    Kevin_K_51432
    Historic F5 Account
    Dec 05, 2013

    Hi, a very outside the box thought: create a cron job / script which runs the command against the process locally. Wrap the command result in html (/var/www/dir). Then just use a simple HTTP monitor and scrape for the results?