How to receive progress data from a running job? - powershell

Question

I have a need to run a bunch of tasks in the background in parallel.
These jobs can run for hours .
But I need all the jobs to give progress while they are running , that the host can read and give a summary of all the jobs at some time interval . For example last task performed and percent completed.
I did a bunch of searching but I didn't find anything on how the host and all the jobs can communicate at run time to achieve my goal.
How to do this with jobs , or are their other way to run things in parallel that facilitate this ?

Answer 1

There is a sample project here: https://key2consulting.com/powershell-how-to-display-job-progress/
It uses Write-Progress in the job to output the status and a loop that monitors the job and displays a progress bar.
Your jobs would need to be designed to output % complete. I.e. Your job would need to know when it is 20% complete.

Answer 2

Here's another solution that does not use progress bars. Your jobs still need to report their progress with periodic writes. If the jobs return data, the data should be stored to a file or other destination. This code reads and discards the returned data as the returned text is used in the update messages.
A better solution could let each job write the status messages to a SQL table and a simple looping screen reads and displays that data. The job's default response is still ready for Receive-Job
For demo purposes only...
#load your jobs here... Note that they periodically report their status.
Start-Job -ScriptBlock {$i = 0; 1..10 | foreach { Start-Sleep -Seconds 1; $i++; "LoopA $($i*10)% complete" }; Start-Sleep -Seconds 1; }
Start-Job -ScriptBlock {$i = 0; 1..10 | foreach { Start-Sleep -Seconds 2; $i++; "LoopB $($i*10)% complete" }; Start-Sleep -Seconds 1; }
Start-Job -ScriptBlock {$i = 0; 1..10 | foreach { Start-Sleep -Seconds 3; $i++; "LoopC $($i*10)% complete" }; Start-Sleep -Seconds 1; }
$joblist = #{} #empty hash table
# get initial list of jobs...
Get-Job | foreach { $joblist.Add( $_.Name, #{ "State"=$_.State;
"HasMoreData"=$_.HasMoreData;
"LastMsg"="" } ) }
# loop and report status
do
{
$done = $true
Get-Job | foreach {
Start-Sleep -Milliseconds 200; # change for you application
# should be more frequent than job messages
# collect data from job
$joblist[$_.Name]["State"] = $_.State;
$joblist[$_.Name]["HasMoreData"] = $_.HasMoreData;
if ($_.State -eq "Running") {
if ($_.HasMoreData) {
# get the message from the job
$txt = (Receive-Job -Name $_.Name)
if ($txt.Count -gt 0) {
$joblist[$_.Name]["LastMsg"] = $txt;
}
}
$done = $false #still have Running jobs
}
}
# report status
cls
$joblist.GetEnumerator() | select Name, {$_.value.State}, {$_.value.HasMoreData}, {$_.value.LastMsg} | ft
} until ($done)
# final status...
cls
$joblist.GetEnumerator() | select Name, {$_.value.State}, {$_.value.HasMoreData}, {$_.value.LastMsg} | ft
# demo clean up.
#Get-Job | Stop-Job
#Get-Job | Remove-Job