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Mem/CPU Information

This document will guide you through adding detection for Memory / Processor for your new device.


Detection for memory is done via two php scripts, one for discovery and the other for polling:


$usage = str_replace('"', "", snmp_get($device, 'iveMemoryUtil.0', '-OvQ', 'PULSESECURE-PSG-MIB'));
if (is_numeric($usage)) {
    discover_mempool($valid_mempool, $device, 0, 'pulse-mem', 'Main Memory', '100', null, null);


echo 'Pulse Secure MemPool\n';
$perc = str_replace('"', "", snmp_get($device, "iveMemoryUtil.0", '-OvQ', 'PULSESECURE-PSG-MIB'));
if (is_numeric($perc)) {
    $memory_available = str_replace('"', "", snmp_get($device, "memTotalReal.0", '-OvQ', 'UCD-SNMP-MIB'));
    $mempool['total'] = $memory_available;
    $mempool['used'] = ($memory_available / 100 * $perc);
    $mempool['free'] = ($memory_available - $mempool['used']);


Detection for processors is done via a yaml file unless custom processing of data is required.



                  oid: iveCpuUtil
                  num_oid: '.{{ $index }}'
                  type: pulse

Available yaml data keys:

Key Default Description
oid required The string based oid to fetch data, could be a table or a single value
num_oid required the numerical oid to fetch data from when polling, usually should be appended by {{ $index }}
value optional Oid to retrieve data from, primarily used for tables
precision 1 The multiplier to multiply the data by. If this is negative, the data will be multiplied then subtracted from 100.
descr Processor Description of this processor, may be an oid or plain string. Helpful values {{ $index }} and {{$count}}
type Name of this sensor. This is used with the index to generate a unique id for this sensor.
index {{ $index }} The index of this sensor, defaults to the index of the oid.
skip_values optional Do not detect this sensor if the value matches

Accessing values within yaml:

{{ $index }} The index after the given oid
{{ $count }} The count of entries (starting with 1)
{{ $oid }} Any oid in the table or pre-fetched
Custom Discovery and Polling

If you need to implement custom discovery or polling you can implement the ProcessorDiscovery interface and the ProcessorPolling interface in the OS class.

OS Class files reside under LibreNMS\OS

namespace LibreNMS\OS;

use LibreNMS\Device\Processor;
use LibreNMS\Interfaces\Discovery\ProcessorDiscovery;
use LibreNMS\Interfaces\Polling\ProcessorPolling;
use LibreNMS\OS;

class ExampleOS extends OS implements ProcessorDiscovery, ProcessorPolling
     * Discover processors.
     * Returns an array of LibreNMS\Device\Processor objects that have been discovered
     * @return array Processors
    public function discoverProcessors()
        // discovery code here

     * Poll processor data.  This can be implemented if custom polling is needed.
     * @param array $processors Array of processor entries from the database that need to be polled
     * @return array of polled data
    public function pollProcessors(array $processors)
        // polling code here