Creating workflow for parallel scheduled server reboots with logging - powershell

Question

I'm currently using the following code to schedule a server reboot. This works pretty well for a handful of servers but becomes a problem when there are many servers (over 80) because Register-ScheduledJob takes a long time per server.
$user = Get-Credential -UserName $env:USERNAME -Message "UserName/password for scheduled Reboot"
$trigger = New-JobTrigger -once -at $date
$script = [ScriptBlock]::Create("D:\Scripts\Scheduled-Reboot-Single.ps1 -server $server")
Register-ScheduledJob -Name $server -Credential $user -Trigger $trigger -ScriptBlock $script
My research pointed to using workflow and foreach -parallel.
The problem I run into is accurate logging. My log file is created but the columns are not ordered correctly.
workflow Do-ScheduledReboot{
Param([string[]]$servers)
foreach -parallel($server in $servers) {
InlineScript {
try {
$LastReboot = Get-EventLog -ComputerName $using:server -LogName system |
Where-Object {$_.EventID -eq '6005'} |
Select -ExpandProperty TimeGenerated |
select -first 1
#New loop with counter, exit script if server did not reboot.
$max = 20; $i = 0
do {
if ($i -gt $max) {
$hash = #{
"Server" = $using:server
"Status" = "FailedToReboot!"
"LastRebootTime" = "$LastReboot"
"CurrentRebootTime" = "FailedToReboot!"
}
$newRow = New-Object PsObject -Property $hash
$rnd = Get-Random -Minimum 5 -Maximum 40
Start-Sleep -Seconds $rnd
Export-Csv D:\workflow-results.csv -InputObject $newrow -Append -Force
exit
}#exit script and log failed to reboot.
$i++
Start-Sleep -Seconds 15
} while (Test-path "\\$using:server\c$")
$max = 20; $i = 0
do {
if ($i -gt $max) {
$hash = #{
"Server" = $using:server
"Status" = "FailedToComeOnline!"
"LastRebootTime" = "$LastReboot"
"CurrentRebootTime" = "FailedToReboot!"
}
$newRow = New-Object PsObject -Property $hash
$rnd = Get-Random -Minimum 5 -Maximum 40
Start-Sleep -Seconds $rnd
Export-Csv D:\workflow-results.csv -InputObject $newrow -Append -Force
exit
}#exit script and log failed to come online.
$i++
Start-Sleep -Seconds 15
} while (-not(Test-path "\\$using:server\c$"))
$CurrentReboot = Get-EventLog -ComputerName $using:server -LogName system | Where-Object {$_.EventID -eq '6005'} | Select -ExpandProperty TimeGenerated | select -first 1
$hash = #{
"Server" = $using:server
"Status" = "RebootSuccessful"
"LastRebootTime" = $LastReboot
"CurrentRebootTime" = "$CurrentReboot"
}
$newRow = New-Object PsObject -Property $hash
$rnd = Get-Random -Minimum 5 -Maximum 40
Start-Sleep -Seconds $rnd
Export-Csv D:\workflow-results.csv -InputObject $newrow -Append -Force
} catch {
$errMsg = $_.Exception
"Failed with $errMsg"
}#end catch
}#end inline script
}#end foreach parallel
}#end workflow
$mylist = gc D:\Servers.txt
Do-ScheduledReboot -servers $mylist

Answer 1

Create ordered hashtables:
$hash = [ordered]#{
'Server' = $using:server
'Status' = ...
"LastRebootTime" = ...
'CurrentRebootTime' = ...
}