Only poll specific ports to reduce CPU %

Marijn_van_Gool · 6 May 2020 12:13

Hello,

I’m aware this has been asked before, but I really need a solution for this.
We have a couple of Juniper MX5 devices with a couple of thousand logical interfaces (VLAN interfaces) which are of course all discovered and polled without any further actions.
In JunOS it’s possible to only allow LibreNMS to poll physical interfaces by configuring a regex, this does part of the job for reducing routing engine CPU %.
In LibreNMS you can configure a regex as well to filter out all interfaces you do not want to discover. However, this doesn’t restrict LibreNMS from going through them all. This will take up to 15 minute to complete a single poll.
Is there a way to configure LibreNMS as such that you can only poll a specific set of ports (per device)?

Beelze

TheGreatDoc · 6 May 2020 12:33

Hello,

Yes. Check https://docs.librenms.org/Support/Performance/#per-port-polling-experimental

Marijn_van_Gool · 6 May 2020 13:10

Thanks!

Could you tell me where I would specify the ports to be polled?

TheGreatDoc · 7 May 2020 07:12

In the ports section of each device.

Not sure if with per port polling + bad_if will just not poll the bad_if ones.

Marijn_van_Gool · 7 May 2020 11:12

Edit > Port Settings is empty (on all devices).
It seems that all pages / scripts get the correct URL (it’s including HTTP port 50080 on where it’s listening to), except for ajax_table.php.
The different HTTP port is because librenms runs on a VM, and the main host is forwarding all HTTP traffic from 50080 to VM’s HTTP port 80.

Could this be the issue (and how would I have this fixed)?