Yamon, Yet Another Monitoring script

In crontab entries I tend to add a> /dev/null 2>&1...

2008-07-12T18:32:00.000+01:00

In crontab entries I tend to add a
> /dev/null 2>&1

The confusing part was, that even with -v, not all the tests appeared in the subject line and it changed from mail to mail whether these listed the SSH or the HTTP tests.

Another thing: are white space characters allowed in the names of tests (with respect to the fail-* files)?

I presume the fail-* files are the only way to really test whether it works, because the -v switch sends a mail anyway, so that confused me a bit.

Thanks for your help.

The -v flag makes it verbose, it repots all the th...

2008-07-12T11:01:00.000+01:00

The -v flag makes it verbose, it repots all the things it tests.

So if you have the -v flag on the crontab entry, that will cause it to generate an e-mail every time it runs - not an e-mail from Yamon, but from crond.

Is that what you're seeing? Otherwise it should only e-mail you on state changes (or periodically based on alert_interval, when things are broken).

Hi again Bjarni,having a bit of a trouble with Yam...

2008-07-12T03:02:00.000+01:00

Hi again Bjarni,

having a bit of a trouble with Yamon. Perl says the syntax is fine. Whenever I run the script with "-v" I get a mail with the subject:

"0 OK spamcop:OK / "

Then after running it a few times (without -v) to get the .state file updated, nothing gets mailed or logged (presumably the right behavior as it is only supposed to mail on failure). However, when I use -v again, I get a mail (almost empty) with the subject of either all my SSH or all my HTTPD tests stating OK.

Is that normal and expected behavior? I skipped pop3 and the smtp-relay test as well as the whitebox test. Otherwise I just added more rules to match my servers.

Thanks.

BTW: you can also reach me as oliver *at* (domain of your previous employer) in case you prefer email.

Nice stuff. Going to try that on my dom0. I am alr...

2008-07-10T23:01:00.000+01:00

Nice stuff. Going to try that on my dom0. I am already running a pretty simplistic shell script in order to check RBLs (using the rblcheck tool), but the other monitoring features may come in handy.

Thanks for publishing it!

Greetings from an alien (terrestrial, though) in Reykjavik ;)

You can tell the script to not alert unless the st...

2007-10-01T12:53:00.000+01:00

You can tell the script to not alert unless the state has been consistant for the past N tests. So "flapping" won't cause an alert at all in many cases.

Generally my alert criteria are "alert if state changes and stays consistent for 3 tests in a row. If it's broken, remind me once every hour until it's fixed".

I want to know when the system recovers as well as knowing when it breaks, so I can stop panicing. :-)

There is one potential problem with this strategy for suppressing "flaps" - if a system flaps once or twice, you probably don't care. If it's flapping for hours, you want to know.

Looks interesting! I have been considering writin...

2007-10-01T11:57:00.000+01:00

Looks interesting! I have been considering writing something similar, able to monitor my web server from my home wireless router (which runs OpenWRT). Unfortunately this doesn't have enough flash for Perl, so shell-script is about the only option. So I may write "yet another yet another monitoring script"....

I see you have a "sanity check" of pinging google.com before doing anything else. Good plan. The other thing that I was considering was doing some sort of exponential back-off: imagine if the server goes down/up/down/up every 5 minutes while you're on holiday, and you're paying $$$ for each SMS. So ideally you'd get an SMS on the first "down", and then another message after n mins, and another after 2n, 4n, 8n etc. etc. Have you considered something like this?