Recently, I set up one-minute ping checks following Fast Ping Checking - LibreNMS Docs on one of my distributed pollers. You can see my /etc/cron.d/librenms for the poller below:
33 */6 * * * librenms /opt/librenms/cronic /opt/librenms/discovery-wrapper.py 1
*/5 * * * * librenms /opt/librenms/discovery.php -h new >> /dev/null 2>&1
* * * * * librenms /opt/librenms/cronic /opt/librenms/poller-wrapper.py 16
*/5 * * * * librenms /opt/librenms/poll-billing.php >> /dev/null 2>&1
01 * * * * librenms /opt/librenms/billing-calculate.php >> /dev/null 2>&1
*/5 * * * * librenms /opt/librenms/check-services.php >> /dev/null 2>&1
* * * * * librenms /opt/librenms/ping.php >> /dev/null 2>&1
I’ve followed all the steps related the rrdcached, and I see the ping data recorded in the UI. I’ve also set an alert to go off every 5 minutes:
However, for some reason I seem to be getting an alert every minute at ~30s mark:
Any idea why that might be the case? Let me know if you need anymore information.
Thanks!
Delay is for the notification.
The alert will fire up in the moment it happens, and wait Delay time to send the notification.
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That makes sense. So if there’s a failed ping, the alert will fire?
I’m still a little confused about why that would happen in this case. How often do the alerts run if not specified in /etc/cron.d/librenms? I have ping running every minute, but the alerts are firing at the half minute. I also tried setting it to have sub-minute ping checks following the same steps by updating ping_rrd_step in config.php and adding
* * * * * librenms /opt/librenms/ping.php >> /dev/null 2>&1
* * * * * librenms sleep 30 && /opt/librenms/ping.php >> /dev/null 2>&1
to /etc/cron.d/librenms, but the alerts would still go off at the half minute mark. I’m pinging localhost on the distributed poller, so I know pings should be consistent on the device.
Yes, a failed ping will fire the alert. In case of fast ping it will fire in the moment it fail.
That makes sense. I think I figured out the source of my issue. I set the device on my poller to poller group 0, but I also had a poller running on my main install that was trying to poll the server that’s running my distributed poller. I’ve deactivated polling/ping/discovery on the main install and moved the devices on the distributed poller to its own group, and the problem seems to be resolved.
Thanks again!
HI Nathanielslam,
I am looking into enabling fast ping (60s) on my distributed infrastructure. I have two poller groups. My main install is a part of poller group id 3 and second poller is a part of group id 6.
I am using rrdcached service on different (3rd) server.
Now to enable fast ping for both pollers. Do i need to make these changes (https://docs.librenms.org/Extensions/Fast-Ping-Check/) on both pollers and rrdcached server?
If its alright, would you be able to share your setup, please.
Regards,
Vik
