Device dependencies - child host sends alert along with parent on reboot

[hugalafutro]

Hi,
I have a PVE server and vm set as parent/child respectively in Librenms, yet when I restart the PVE node, I get 2 alerts on Telegram for both the node and the vm. Am I setting it wrong or how would I go about only getting an alert for the node and not the children devices ?

example

Thanks!

[murrant]

Device dependencies aren’t guaranteed to work except up/down ones using the fast ping script.

Normal polling can be out of “order”, so it won’t know the parent is down when the child is polled sometimes.

[hugalafutro]

I see, is there any way to use fast ping in docker? I am already using 1min polling, but guess that’s not fast enough/relevant.

[murrant]

fast ping is just the name of it. If you only want 1 minute up/down alerts, I highly suggest you use it and go back to 5 minute polling.

I think all you need to do is set these settings in the webui:

[SantiagoSilvaZ]

@murrant, the documentation states that it is necessary:
4: Add the following line to /etc/cron.d/librenms to allow 1 minute ping checks

*    *    * * *   librenms    /opt/librenms/ping.php >> /dev/null 2>&1

If enabled via WebUI, I still have to change cron.d?

[murrant]

No, that setting in the webui enables the schedule in the dispatcher service (which the docker image uses)

You do still need to run this once as stated by the docs.

./scripts/rrdstep.php -h all