About Parallel

SHORT DESCRIPTION

Describes the Parallel keyword, which runs the activities in a workflow in parallel.

LONG DESCRIPTION

The Parallel keyword runs workflow activities in parallel. This keyword is valid only in Windows PowerShell Workflow.

SYNTAX

workflow <Verb-Noun>
{
     Parallel
     {
          [<Activity>]
          [<Activity>]
        ...
     }
 }

DETAILED DESCRIPTION

The commands in a Parallel script block can run concurrently. The order in which they run is not determined.

For example, the following workflow includes a Parallel script block that runs activities that get processes and services on the computer. Because the Get-Process and Get-Service commands are independent of each other, they can run concurrently and in any order.

workflow Test-Workflow
{
    Parallel
    {
         Get-Process
         Get-Service
    }
}

Running commands in parallel is very efficient and reduces the time it takes to complete a workflow significantly.

To run selected commands in a Parallel script block in sequential order, use the Sequence keyword. For more information, see about_Sequence.

To run a Parallel script block on items in a collection, use the ForEach or ForEach -Parallel keywords.

SEE ALSO

"Writing a Script Workflow"

about_ForEach

about_ForEach-Parallel

about_Language_Keywords

about_Sequence

about_Workflows