feat(os/aix/snmp): add memory monitoring mode via hrStorageTable

[senbonzak]

Description

Add a new memory mode to the os::aix::snmp plugin to monitor physical RAM
usage on AIX servers via SNMP HOST-RESOURCES-MIB.

The existing modes cannot monitor RAM on AIX because AIX SNMP agents expose RAM
under hrStorageType = hrStorageRam (.1.3.6.1.2.1.25.2.1.2) with a dynamic
index that must be discovered by scanning the full hrStorageTable. This mode
handles that discovery automatically.

Type of change

• New functionality (non-breaking change)

How this pull request can be tested ?

Requirements:

• AIX server with SNMP agent configured (v1, v2c or v3)
• centreon-plugins installed

Command:
/usr/lib/nagios/plugins/centreon_plugins.pl --plugin=os::aix::snmp::plugin --mode=memory --hostname=<AIX_IP> --snmp-version=2c --snmp-community= --warning-usage=80 --critical-usage=90

Expected output:
CRITICAL: Ram Total: 90.00 GB Used: 82.81 GB (92.02%) Free: 7.19 GB (7.98%)
| 'memory_used'=88920719360B;... 'memory_free'=7715979264B;... 'memory_usage'=92.02%;80;90;0;100

SNMP data (hrStorageTable extract):
HOST-RESOURCES-MIB::hrStorageType.21 = OID: HOST-RESOURCES-TYPES::hrStorageRam
HOST-RESOURCES-MIB::hrStorageAllocationUnits.21 = INTEGER: 4096 Bytes
HOST-RESOURCES-MIB::hrStorageSize.21 = INTEGER: 16777216
HOST-RESOURCES-MIB::hrStorageUsed.21 = INTEGER: 16576949

Note: the RAM index (here .21) is dynamic and varies across AIX systems.

Checklist

• I have followed the coding style guidelines provided by Centreon
• I have commented my code, especially hard-to-understand areas of the PR
• I have rebased my development branch on the base branch (develop)
• I have provide data or shown output displaying the result of this code in the plugin area concerned

Summary by Aikido

Security Issues: 0	Quality Issues: 0	Resolved Issues: 0

🚀 New Features

• Added memory monitoring mode for AIX via hrStorageTable discovery

^{More info}

[Evan-Adam]

Hello @senbonzak
Could you try to use the storage mode of the AIX plugin with the option --filter-storage-type='hrStorageRam$' ?

The $ should make the plugin ignore the hrStorageRamDisk disk type, which I don't know the use.

It seem the ram is considered as a disk, and this mode should allow you to monitor most value in this table.

If the percentage is wrong, please try to play with --space-reservation parameter that might screw the calculation if active.

Thanks,

[senbonzak]

Hi, thanks for the suggestion!

I tested both approaches on the same AIX host (60 GB RAM, SNMP v1) and here are the results:

Storage mode (your suggestion):

/usr/lib/centreon/plugins/centreon_aix_snmp.pl \
  --plugin=os::aix::snmp::plugin \
  --mode=storage \
  --hostname=10.147.130.152 \
  --snmp-version='x' \
  --snmp-community='xxxxxxx' \
  --filter-storage-type='hrStorageRam$' \
  --warning-usage='90' --critical-usage='95' 

CRITICAL: Storage 'System RAM' Usage Total: 60.00 GB Used: 58.22 GB (97.03%) Free: 1.78 GB (2.97%) | 'count'=1;;;0; 'used'=62510997504B;0:57982058496;0:61203283968;0;64424509440

Memory mode (this PR):

/usr/lib/nagios/plugins/centreon_plugins.pl \
  --plugin=os::aix::snmp::plugin \
  --mode=memory \
  --hostname=10.147.130.152 \
  --snmp-version='x' \
  --snmp-community='xxxxxx' \
  --warning-usage='90' --critical-usage='95' --verbose

CRITICAL: Ram Total: 60.00 GB Used: 58.22 GB (97.03%) Free: 1.78 GB (2.97%) | 'memory_used'=62511030272B;0:57982058496;0:61203283968;0;64424509440 'memory_free'=1913479168B;0:90;0:95;0;64424509440 'memory_usage'=97.03%;0:90;0:95;0;100

Both modes return identical values. They both read the same hrStorageRam entry from hrStorageTable.

However, I believe the dedicated memory mode still brings real value for the following reasons:

1. There is currently no memory monitoring for AIX in the official connector

Looking at the official Centreon documentation for the AIX SNMP connector (https://docs.centreon.com/pp/integrations/plugin-packs/procedures/operatingsystems-aix-snmp/), there is no memory mode and no service template dedicated to physical RAM monitoring. The available modes are: cpu, storage, swap, interfaces, processcount, time, and uptime , but nothing for RAM or Memory.

This means that today, a Centreon user who wants to monitor physical RAM on an AIX server has no native, explicit solution. The only workaround is using --mode=storage with --filter-storage-type='hrStorageRam$', which is not documented anywhere in the connector's documentation and is far from intuitive.

2. Usability and consistency

Using --mode=memory is self-explanatory and consistent with how other OS plugins already work in centreon-plugins (Linux, Windows, etc.). Users should not need to understand the internals of hrStorageTable and storage type filtering just to monitor RAM on an AIX server.

I think adding a dedicated memory mode is ultimately simpler for end users than documenting a storage mode workaround. It just works out of the box without any extra filtering knowledge required.

Thanks again for your feedback!