Overview Traffic Graph broken: RRDTool Output ERROR: can not parse an empty rpn expression

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1

After adding more network interfaces to a Ubuntu system, LibreNMS is no longer showing the overview graph for that Ubuntu system.

The error message for the graph is: RRDTool Output ERROR: can not parse an empty rpn expression

Deleting the Ubuntu system from LibreNMS and adding it again does not solve the problem.

Under Ports for that system nothing is shown. In the settings panel for that system I am able to see the interfaces with descriptions.

./validate.php

Component Version
LibreNMS 1.47-87-g45e0e5e19
DB Schema 1000
PHP 7.2.10-0ubuntu0.18.04.1
MySQL 10.1.34-MariaDB-0ubuntu0.18.04.1
RRDTool 1.7.0
SNMP NET-SNMP 5.7.3

====================================

[OK] Composer Version: 1.8.0
[OK] Dependencies up-to-date.
[OK] Database connection successful
[OK] Database schema correct

2

I’ll start with a -d discovery and poller commands.

./discovery.php -d -h ubuntuhost -m ports and the same with poller.php.

Then check the output to try to determine why is failing.

3

When I see this from the discover https://gist.github.com/SandroRaV/8c87d3051c8faf597818bdc581618695 and the poller https://gist.github.com/SandroRaV/44fceaf52ade67c3c36f91ddc56665c2 it fails after reading an interface that is not enabled and not up. It happens everytime the discovery or the poller is run.

I tried different things with removing the alias I had in the config and so on but no chance to get it into librenms