DisplayData convertion didn't work as expected

[ThomasUllrich666]

Host operating system: output of uname -a

Linux sekidp-snmp-exporter-756d7b848c-5qj2h 4.18.0-477.13.1.el8_8.x86_64 #1 SMP Thu May 18 10:27:05 EDT 2023 x86_64 GNU/Linux

snmp_exporter version: output of snmp_exporter -version

snmp_exporter, version 0.23.0 (branch: HEAD, revision: 20657d2)
build user: root@f2310b8dd92c
build date: 20230816-09:56:45
go version: go1.20.7
platform: linux/amd64
tags: netgo

What device/snmpwalk OID are you using?

ThinkSystem SR630 V2
OID: 1.3.6.1.4.1.19046.11.1.1.1.2.1.3
https://www.circitor.fr/Mibs/Html/L/LENOVO-XCC-MIB.php#tempReading

If this is a new device, please link to the MIB(s).

https://www.circitor.fr/Mibs/Html/L/LENOVO-XCC-MIB.php

What did you do that produced an error?

I want to override the Display string parameter of the temperature value to a gauge datatype.
Currently the temperature value is represented as a String that lead to the situation that each value will be represented as a label in prometheus.

Therefore I added the overrides parameter to mark it as gauge.

Unfortunately this didn't work. The snmp agent captures always 0 instead of the values.

lenovo-xcc:
walk:
- temperature
- voltage
- fans
- systemHealth
- leds
- hostMACAddressTable
- xccVpdEntry
- spTxtId
- machineVpd
overrides:
voltReading:
type: gauge
voltNominalReading:
type: gauge
voltNonRecovLimitHigh:
type: gauge
voltNonCritLimitHigh:
type: gauge
voltNonRecovLimitLow:
type: gauge
voltCritLimitHigh:
type: gauge
voltCritLimitLow:
type: gauge
voltNonCritLimitLow:
type: gauge
tempReading:
type: gauge
tempNominalReading:
type: gauge
tempNonRecovLimitHigh:
type: gauge
tempNonCritLimitHigh:
type: gauge
tempNonRecovLimitLow:
type: gauge
tempCritLimitLow:
type: gauge
tempNonCritLimitLow:
type: gauge

What did you expect to see?

the temperature values

What did you see instead?

just 0

[0xhessam]

I have the same issue, changing the DisplayString to gauge doesn't work.
Issue Overview

When monitoring Lenovo devices using the SNMP protocol, the values fetched are primarily in the STRING data type. This is inconsistent with other manufacturers, such as Dell, which provides more usable SNMP data types like INTEGER or GAUGE.

MIB File in Use

lnvgy_fw_xcc_d8bt54m-5.00_lenovoxcc-anyos_noarch.mib

Example Data

Lenovo Devices

Most of the values from Lenovo devices are STRING:

SNMPv2-SMI::enterprises.19046.11.1.1.1.2.1.3.1 = STRING: "25"
SNMPv2-SMI::enterprises.19046.11.1.1.1.2.1.3.2 = STRING: "39"
...

Dell Devices

In contrast, values from Dell devices are usually INTEGER:

SNMPv2-SMI::enterprises.674.10892.5.4.700.20.1.6.1.1 = INTEGER: 620
SNMPv2-SMI::enterprises.674.10892.5.4.700.20.1.6.1.2 = INTEGER: 660
...

Specific Areas of Concern

Fan Speed Metrics: Currently provided in percentage and as a string.

SNMPv2-SMI::enterprises.19046.11.1.1.3.2.1.3.1 = STRING: " 74% of maximum"
...

Desired Format: Values should be in RPM for effective graphing.

Fan Status: Also represented as strings.

SNMPv2-SMI::enterprises.19046.11.1.1.3.2.1.10.1 = STRING: "Normal"
...

Power Status: Presented as strings.

SNMPv2-SMI::enterprises.19046.11.1.1.11.2.1.6.1 = STRING: "Normal"
...

Conclusion

Having SNMP data in more quantifiable types like INTEGER or GAUGE would make monitoring and graphing significantly more straightforward and accurate. Therefore, it's crucial to address these discrepancies for more efficient device management.

[0xhessam]

For instance, when monitoring fan speed metrics from Lenovo devices, the SNMP data returned is as follows:

fanSpeed{ fanIndex="1", fanSpeed=" 74% of maximum", hostname="####", instance="####", job="####", prometheus="####", prometheus_replica="####", rack="####", region="####", site="####", snmp="####", team="####"} and then 1

[SuperQ]

This is what the regex_extracts is used for. It allows you to parse the numbers out of arbitrary strings.

[0xhessam]

Could you please give me an example, I read this but cannot find the correct template for it.
what is the correct regex for this value:
fanSpeed{ fanIndex="1", fanSpeed=" 74% of maximum", hostname="####", instance="####", job="####", prometheus="####", prometheus_replica="####", rack="####", region="####", site="####", snmp="####", team="####"} and then 1

I want to have the 74 as a string value and the end.

[0xhessam]

I added this but cannot fetch fanSpeed anymore in Prometheus (no value).

    overrides:
      fanSpeed:
        regex_extracts:
          fanSpeedtest:
            - regex: '(.*)'
              value: '$1'

[0xhessam]

This is the final regex for fan speed, it returns the number (50) instead of (50%), but this created another metric called "fanSpeedPercentage"

    overrides:
# Extract fan speed percentage from string
      fanSpeed:
        type: DisplayString
        regex_extracts:
          Percentage:
            - regex: '\s*(\d{1,3}).*'
              value: '$1'

Thanks to Jacob from Lenovo team to clarify this matter.