Adjusting Polling modules for 1 device

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1

librenms]# ./validate.php

Component Version
LibreNMS 1.40-9-g78e3df4
DB Schema 251
PHP 5.6.36
MySQL 5.1.73
RRDTool 1.3.8
SNMP NET-SNMP 5.5

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

[OK] Composer Version: 1.6.5
[OK] Dependencies up-to-date.
[OK] Database connection successful
[OK] Database schema correct

Using Chrome Version 66.0.3359.181 (Official Build) (64-bit)

Problem: When LibreNMS polls Juniper MX104s, it causes a CPU spike. Juniper TAC said it’s the bulkget/bulkwalk mechanism that is causing this. I looked at the poller history, and it seems like the polling of OSPF and the processors are what’s causing the increased time during the poll (will paste a screen shot). So I think polling these two may also be causing the spike in CPU utilization on the MX104s.

Question: How do I specifically disable either bulkget/bulkwalk and just use get/walk for these specific devices?

Question: I was looking at global settings, and there appear to be generic devices in there. Based on:
https://docs.librenms.org/#Support/Performance/
https://docs.librenms.org/#Support/Poller%20Support/
It sounds like I can disable polling for these specific modules, but I am not clear on how exactly to do that. Any help would be appreciated.

Ideally, I would like to still poll and get this information, but I do not want to cause these CPU spikes that go above 85% utilization.

Thanks

2

Screen shot

ospf-processors-taking-toolong
ospf-processors-taking-toolong558×692 103 KB

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To turn off polling modules; in the web UI . Go on the device -> Edit Device -> Modules

4

@Chas Do you know if there’s a way to change from SNMP BulkGet to just SNMP Get for a particular device?

5

No idea. What happens if you turn off all polling modules except leave the CPU module on? Does it fix your CPU spikes ?

I wonder if there is a another way you can monitor CPU (either on the device) and temporarily turn off polling from librenms to see if it fixes

6

Add
nobulk: true

to includes/definitions/junos.yaml

It will disable bulkwalk on this OS.

Or just
$config[‘os’][‘junos’][‘nobulk’] = 1;
in config.php

2 Likes
7

sorry for late reply. I need to wait until I can re-enable the SNMP on the device. We disabled it and are in freeze at the moment. Will reply back.