[Xymon] Linux client with local-config (or bb-memory.sh for linux)

[John Thurston]

On 10/11/2018 2:45 PM, John Thurston wrote:
...
> I'm in need of memory monitoring on a CentOS 7 host. The client I have 
> there (I think it is a BBPE version) doesn't provide it. So I reached 
> back and grabbed a bb-memory.sh from some other system. But it doesn't 
> work cleanly :(
...> my version of 'free' (3.3.10) has moved the '+/-' information up
> into a new column in the 'Mem' line. I don't see a way to adjust the 
> 'free' command to return results in the old format, so I'll need to 
> accommodate the new format in the shell script.

Digging in, I think I've figured out the line missing from the 'free -m' 
output is irrelevant with the new reporting done by free.

For reference:
> https://askubuntu.com/questions/770108/what-do-the-changes-in-free-output-from-14-04-to-16-04-mean

> https://serverfault.com/questions/85470/meaning-of-the-buffers-cache-line-in-the-output-of-free

What I've done (in the linux block of bb-memory.sh) is preface the line:
   ACT_MEMORY_USED=`echo $FREE_ACT | $AWK '{ print $3; }'`
with a conditional
   [ "$FREE_ACT" ] &&

On systems which have internalized the calculation of free memory, the 
ACT_MEMORY_USED variable will be left at -1 (its initial value as set in 
the script), and later code will not barf with a "unary operator" error 
due to the empty string returned by grep.

And so do I perpetuate the use of ancient code.

-- 
    Do things because you should, not just because you can.

John Thurston    907-465-8591
John.Thurston at alaska.gov
Department of Administration
State of Alaska