Implementing a blacklist check in zabbix ... / 2010-10-04

Implementing a blacklist check in zabbix was a bit more complicated than I originally thought. Searching for it found Monitor DNS blacklist entries - zabbix forums which points at Monitor DNS blacklist entries with Zabbix - Penumbra where shell scripts are suggested. I decided to rewrite stuff in perl using Net::DNS because I wanted a bit more robustness.

Well, as the docs for Net::DNS say:

BUGS
       "Net::DNS" is slow.

checking 89 blacklists took about 25 seconds. Default external checks in zabbix need to be done in 3 seconds.

As a crummy workaround I now run the checks from cron every 15 minutes which dump the result in a tempfile and the check is on the content of the tempfile, also every 15 minutes. Crude, but effective.