Public/Get-DMHostPerformance.ps1

function Get-DMHostPerformance {
    <#
    .SYNOPSIS
        Retrieves realtime performance samples for OceanStor hosts.
 
    .DESCRIPTION
        Thin wrapper around Get-DMPerformance for object type Host. Accepts one or more
        OceanStorHost objects via pipeline (e.g. from Get-DMhost), batches all piped IDs into a
        single performance_data call per sample -- required because the endpoint cannot be
        invoked concurrently.
 
    .PARAMETER WebSession
        Optional parameter to define the session to be use on the REST call. If not defined, the module's cached $script:CurrentOceanstorSession session will be used
 
    .PARAMETER InputObject
        One or more OceanStorHost objects, pipeline-able.
 
    .PARAMETER Metric
        One or more friendly metric names (see Get-DMPerformanceIndicatorMap). Defaults to
        Get-DMPerformance's own default set when omitted.
 
    .PARAMETER SampleCount
        Number of samples to take. Defaults to 1.
 
    .PARAMETER IntervalSeconds
        Delay between samples when SampleCount is greater than 1. Defaults to 5.
 
    .INPUTS
        OceanStorHost
 
    .OUTPUTS
        System.Collections.ArrayList
 
    .EXAMPLE
        PS> Get-DMhost | Get-DMHostPerformance
 
    .NOTES
        Filename: Get-DMHostPerformance.ps1
    #>

    [CmdletBinding()]
    [OutputType([System.Collections.ArrayList])]
    param(
        [Parameter(ValueFromPipelineByPropertyName = $true, Mandatory = $false)]
        [pscustomobject]$WebSession,

        [Parameter(Mandatory = $true, Position = 0, ValueFromPipeline = $true)]
        [object[]]$InputObject,

        [Parameter(Mandatory = $false)]
        [ArgumentCompleter({
                param($commandName, $parameterName, $wordToComplete, $commandAst, $fakeBoundParameters)
                (Get-DMPerformanceIndicatorMap).Keys | Where-Object { $_ -like "$wordToComplete*" }
            })]
        [ValidateScript({
                $validNames = (Get-DMPerformanceIndicatorMap).Keys
                foreach ($metricName in $_) {
                    if ($metricName -notin $validNames) {
                        throw "Unknown performance metric '$metricName'. Valid metrics: $($validNames -join ', ')"
                    }
                }
                return $true
            })]
        [string[]]$Metric,

        [Parameter(Mandatory = $false)]
        [int]$SampleCount = 1,

        [Parameter(Mandatory = $false)]
        [int]$IntervalSeconds = 5
    )

    begin {
        $session = if ($WebSession) { $WebSession } else { $script:CurrentOceanstorSession }
        $ids = [System.Collections.Generic.List[string]]::new()
    }

    process {
        foreach ($obj in $InputObject) {
            if ($obj -isnot [OceanStorHost]) {
                throw "Get-DMHostPerformance: InputObject must be an OceanStorHost object."
            }
            $ids.Add($obj.Id)
        }
    }

    end {
        if ($ids.Count -eq 0) { return }

        $params = @{ WebSession = $session; ObjectType = 'Host'; ObjectId = @($ids) }
        if ($PSBoundParameters.ContainsKey('Metric')) { $params.Metric = $Metric }

        for ($s = 0; $s -lt $SampleCount; $s++) {
            Get-DMPerformance @params
            if ($s -lt ($SampleCount - 1)) { Start-Sleep -Seconds $IntervalSeconds }
        }
    }
}