multithreading - Powershell Throttle Multi thread jobs via job completion

Question

All the tuts I have found use a pre defined sleep time to throttle jobs. I need the throttle to wait until a job is completed before starting a new one. Only 4 jobs can be running at one time.

So The script will run up 4 and currently pauses for 10 seconds then runs up the rest. What I want is for the script to only allow 4 jobs to be running at one time and as a job is completed a new one is kicked off.

Jobs are initialised via a list of servers names.

Is it possible to archive this?

$servers = Get-Content "C:empflashfilestoreserverlist.txt"

$scriptBlock = { #DO STUFF }


$MaxThreads = 4

foreach($server in $servers) {
     Start-Job -ScriptBlock $scriptBlock -argumentlist  $server 
     While($(Get-Job -State 'Running').Count -ge $MaxThreads) {
          sleep 10 #Need this to wait until a job is complete and kick off a new one.
     }
}
Get-Job | Wait-Job | Receive-Job

Answer 1

You can test the following :

$servers = Get-Content "C:empflashfilestoreserverlist.txt"
$scriptBlock = { #DO STUFF }
invoke-command -computerName $servers -scriptblock $scriptBlock -jobname 'YourJobSpecificName' -throttlelimit 4 -AsJob

This command uses the Invoke-Command cmdlet and its AsJob parameter to start a background job that runs a scriptblock on numerous computers. Because the command must not be run more than 4 times concurrently, the command uses the ThrottleLimit parameter of Invoke-Command to limit the number of concurrent commands to 4.

Be careful that the file contains the computer names in a domain.