enh(storage::dell::me4::restapi): Add tier distribution and page allocation metrics to volume-statistics mode

[JackTor]

feat(storage/dell/me4): add tier distribution and page allocation metrics

Community contributors

Description

The current volume-statistics mode does not export tier distribution metrics that are already available in the /api/show/volume-statistics API response. This is a enhancement

New metrics added

• percent-tier-ssd → volume.tier.ssd.percentage (%)
• percent-tier-sata → volume.tier.archive.percentage (%)
• percent-tier-sas → volume.tier.sas.percentage (%)
• percent-allocated-rfc → volume.tier.rfc.percentage (%)
• pages-alloc-per-minute → volume.pages.allocated.perminute
• pages-dealloc-per-minute → volume.pages.deallocated.perminute

Type of change

• Patch fixing an issue (non-breaking change)
• New functionality (non-breaking change)
• Functionality enhancement or optimization (non-breaking change)
• Breaking change (patch or feature) that might cause side effects breaking part of the Software

How this pull request can be tested ?

Monitor data tiering behavior per volume. Useful for capacity planning and detecting SSD tier saturation (hot data spilling to slower tiers).

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Testing

Tested on Dell PowerVault ME5084 (~300 volumes) with Centreon 25.10.14 Community Edition

Output example:
sudo -u centreon-engine /usr/lib/centreon/plugins/centreon-plugins/src/centreon_plugins.pl --plugin=storage::dell::me4::restapi::plugin --mode=volume-statistics --hostname=localhost --api-username=user--api-password=*** --port=443 --proto=https --insecure --digest-sha256 --filter-name='DISK_CLIENTE'
OK: All volumes statistics are ok | 'DISK_CLIENTE#volume.data.transfer.bytespersecond'=0B/s;;;0; 'DISK_CLIENTE#volume.iops.ops'=0ops;;;0; 'DISK_CLIENTE#volume.cache.write.usage.percentage'=0;;;0; 'DISK_CLIENTE#volume.tier.ssd.percentage'=11;;;0;100 'DISK_CLIENTE#volume.tier.archive.percentage'=88;;;0;100 'DISK_CLIENTE#volume.tier.sas.percentage'=0;;;0;100 'DISK_CLIENTE#volume.tier.rfc.percentage'=0;;;0;100 'DISK_CLIENTE#volume.pages.allocated.perminute'=0;;;0; 'DISK_CLIENTE#volume.pages.deallocated.perminute'=0;;;0;

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.