Writing PowerCLI for Performance

I was building a piece of PowerCLU code to check on my vCD Deployed vAPPs for certain errors and because it’s me I was curious what performance difference there was between using array based operations verses piped operations in powershell. Here’s what I found out.

Here is the array based operation – time to completion 2 minutes 30 seconds.

$myVAPP = @(Get-CIVApp | Select-Object Org, Name, Status)
        foreach ($myVAPP.Name in $myVAPP)
            {
                IF ($myVAPP.Status -eq "FailedCreation")
                    {
                        Write-Host 'vAPP' $myVAPP.Name' - Status is' $myVAPP.Status
                    }
                ELSE
                    {
                            IF ($myVAPP.Status -eq "Unresolved")
                            {
                                Write-Host 'vAPP' $myVAPP.Name' - Status is' $myVAPP.Status
                            }
                            else
                            {
                                IF ($myVAPP.Status -eq "Unknown")
                                {
                                    Write-Host 'vAPP' $myVAPP.Name' - Status is' $myVAPP.Status
                                }
                                else
                                {
                                }
                            }                           
                    }
            }
           

Here is the pipe based operation which is recommended for reasons that I now can testify for first hand.

Get-CIVApp -Status "Unresolved", "FailedCreation", "Unknown", "Unrecognized" | Select-Object Org, Name, Status

This operation returned the same results as the array based operation in 14 seconds, that’s 9% of the original time of using an array…