Multithreading a powershell script and challenges - powershell

Question

I have developed a script which does a lot of processing for a front end tool, now I am attempting to have the script run with multiple threads. It interacts a lot with SQL databases, this should not be a problem for multithreading as the database transactions are very short lived, and the queries well optimised.
what is the issue ?
#.\tester.ps1 -servers (1,'Server1',3,1),(2,'Server2',3,1) -output_folder 'C:\temp'
param ([array[]]$servers),$output_folder
for ($i = 0; $i -lt $servers.Count; $i++)
{
$myserverid = $servers[$i][0]
$myservername = $servers[$i][1]
$mylocationid = $servers[$i][2]
$myappid = $servers[$i][3]
write-output " $myserverid and $myservername and $mylocationid and $myappid"
invoke-sqlcmd -ServerInstance "$myservername" -query "select top 10 name from sysobjects" -Database "master"
}
The script file above will gets passed an array of servers and currently it will loop through the array one by one. A way for me to make the process faster is to run the script in parallel /run the script with multiple threads.
Research
I have looked at a technet script on https://gallery.technet.microsoft.com/scriptcenter/Run-a-PowerShell-script-991c8a42
Its not quite the same as my array is not just a list of servers, there will be other parameters sent with it.
What am I after
A way or pointer to make the script be able to run in parallel or an example using the provided script above.
Thanks in advance.

Answer 1

Extending my comment. In PowerShell v5, use Jobs and Workflows for Parallel use cases.
# Example using parallel jobs
$start = Get-Date
# get all hotfixes
$task1 = { Get-Hotfix }
# get all scripts in your profile
$task2 = { Get-Service | Where-Object Status -eq Running }
# parse log file
$task3 = { Get-Content -Path $env:windir\windowsupdate.log | Where-Object { $_ -like '*successfully installed*' } }
# run 2 tasks in the background, and 1 in the foreground task
$job1 = Start-Job -ScriptBlock $task1
$job2 = Start-Job -ScriptBlock $task2
$result3 = Invoke-Command -ScriptBlock $task3
# wait for the remaining tasks to complete (if not done yet)
$null = Wait-Job -Job $job1, $job2
# now they are done, get the results
$result1 = Receive-Job -Job $job1
$result2 = Receive-Job -Job $job2
# discard the jobs
Remove-Job -Job $job1, $job2
$end = Get-Date
# Example, using WorkFlow
workflow Test-WFConnection
{
param
(
[string[]]$Computers
)
foreach -parallel ($computer in $computers)
{
Test-Connection -ComputerName $computer -Count 1 -ErrorAction SilentlyContinue
}
}