CODEWITHSUNDEEP
powershellqueuestart-job
Joe Brown
Joe Brown

Reputation: 63

PowerShell Job Queue

Run a job for each server in a list. I only want 5 jobs running at a time. When a job completes, it should start a new job on the next server on the list. Here's what I have so far, but I can't get it to start a new job after the first 5 jobs have ran:

   $MaxJobs = 5
   $list = Get-Content ".\list.csv"
   $Queue = New-Object System.Collections.Queue
   $CurrentJobQueue = Get-Job -State Running
   $JobQueueCount = $CurrentJobQueue.count

   ForEach($Item in $list)
  {
  Write-Host "Adding $Item to queue"
  $Queue.Enqueue($Item)
  }

 Function Global:Remote-Install
 {
 $Server = $queue.Dequeue()
 $j = Start-Job -Name $Server -ScriptBlock{

        If($JobQueueCount -gt 0)
        {
        Test-Connection $Server -Count 15
        }##EndIf
    }##EndScriptBlock

  }

For($i = 0 ;$i -lt $MaxJobs; $i++) 
{
Remote-Install
}

Upvotes: 3

Views: 10345

Answers (2)

Keith Hill
Keith Hill

Reputation: 201832

PowerShell will do this for you if you use Invoke-Command e.g.:

Invoke-Command -ComputerName $serverArray -ScriptBlock { .. script here ..} -ThrottleLimit 5 -AsJob

BTW I don't think your use of a .NET Queue is going to work because Start-Job fires up another PowerShell process to execute the job.

Upvotes: 4

Roman Kuzmin
Roman Kuzmin

Reputation: 42063

You may take a look at the cmdlet Split-Pipeline of the module SplitPipeline. The code will look like:

Import-Module SplitPipeline
$MaxJobs = 5
$list = Get-Content ".\list.csv"
$list | Split-Pipeline -Count $MaxJobs -Load 1,1 {process{
    # process an item from $list represented by $_
    ...
}}

-Count $MaxJobs limits the number of parallel jobs. -Load 1,1 tells to pipe exactly 1 item to each job.

The advantage of this approach is that the code itself is invoked synchronously and it outputs results from jobs as if all was invoked sequentially (even output order can be preserved with the switch Order).

But this approach does not use remoting. The code works in the current PowerShell session in several runspaces.

Upvotes: 3

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