RaiseEvent-Call doesn't transmit content/body to Orchestrator

[amazingidiot]

Hello,
I'm running a durable function with the human interaction pattern like in the human interaction example . I successfully raise the event in a separat azure function via a HTTP call according to the documentation. In line 22, $approvalEvent, the return value of the Start-DurableExternalEventListener is used as the input for the activity. I assume that that's the value of the body that's send with the HTTP-call to raise the event, although it is not actually used in the activity itself in the example. I managed to capture the message in the queue, and the body is in there under TaskMessage.Event.Input. If I convert the $approvalEvent to JSON, it is just "{}".
Is the message body not available in powershell or is there a cmdlet to query the data? The documentation is incomplete on this so far.

Please let me know if I can provide further information! Thank you!

Best regards,
Oliver

[amazingidiot]

Hi,
any news on this issue? Do you need more information from me?
Thanks!

[davidmrdavid]

Hi @amazingidiot,

No updates yet, sorry to keep you waiting. I've assigned this ticket to me to help track it and I'll start looking into it as soon as possible. It seems to me, from looking at the description, that this is a bug in the SDK implementation, but I'll need a few days of exploration before being able to make that determination. We'll update this thread as soon as possible.

[amazingidiot]

Hi @davidmrdavid,
thank you for the reply! Again, if I can provide more information, please tell me.

Best regards!

@amazingidiot I was also having the same issue as you so I decided to look in to the issue.

When Wait-DurableTask is used with the -Any parameter a task is returned to PowerShell not the resulting job status, output or event. This is a different behaviour to Wait-DurableTask without the -Any parameter. In this case it returns an array of all the results. This is why you and I were both seeing {} returned.

To ensure compatibility with existing code and logic I created a new command Get-DurableTaskResult. To this you pass a task to get the results. You can pass any task you like (that has completed), but it's best to pass the output of Wait-DurableTask as this will return the first completed task (as per the logic for the -Any paramater).

Below you can find the modified demo HelloOrchestration logic. You can see it contains a timeout task, the main activity task and two event tasks. I then wait for any of these to trigger in a loop. If the activity finishes the loop completes and the Orchestration is completed.

using namespace System.Net

param($Context)

Set-DurableCustomStatus -CustomStatus 'Processing Tokyo'

Write-Host "Start Activity"
$ParallelActivity = Invoke-DurableActivity -FunctionName 'Hello' -Input 'Tokyo' -NoWait
Write-Host "Activity started"

$ActivityComplete = $false
while (!$ActivityComplete) {
    # Set a timeout
    $ApprovalTimeOut = New-TimeSpan -Seconds 60
    $DurableTimeoutEvent = Start-DurableTimer -Duration $ApprovalTimeOut -NoWait

    # Set events to listen for
    $DurableActivityUpdate = Start-DurableExternalEventListener -EventName "TESTEVENTNAME" -NoWait
    $DurableActivityUpdate2 = Start-DurableExternalEventListener -EventName "TESTEVENTNAME2" -NoWait

    # Wait for event or task to complete
    $CompleteRunningTask = Wait-DurableTask -Task @($DurableActivityUpdate, $DurableActivityUpdate2, $ParallelActivity, $DurableTimeoutEvent) -Any

    # Event Raised
    if ($CompleteRunningTask -eq $DurableTimeoutEvent) {
        Write-Host "Timeout!"
        $ActivityComplete = $true
        Stop-DurableTimerTask -Task $DurableTimeoutEvent
        return
    }
    if ($CompleteRunningTask -eq $DurableActivityUpdate) {
        Write-Host "status update"
        Write-Host $(Get-DurableTaskResult -Task @($CompleteRunningTask) | ConvertTo-Json -Depth 100)
    }
    if ($CompleteRunningTask -eq $DurableActivityUpdate2) {
        Write-Host "status update 2"
        Write-Host $(Get-DurableTaskResult -Task @($CompleteRunningTask) | ConvertTo-Json -Depth 100)
    }
    if ($CompleteRunningTask -eq $ParallelActivity) {
        Write-Host "Activity Complete"
        Write-Host $(Get-DurableTaskResult -Task @($CompleteRunningTask) | ConvertTo-Json -Depth 100)
        $ActivityComplete = $true
        Stop-DurableTimerTask -Task $DurableTimeoutEvent
    }
}

Write-Host "Orchestration complete"

$output

Below is the Hello activity. You will see I've created a custom Send-DurableExternalEvent function as the inbuilt function doesn't work on Azure due to the App code not being specified. I have added that as a parameter on this commit too.

using namespace System.Net

param($Request, $TriggerMetadata)

"Hello $Request!"

# Set instance ID
$InstanceId = $TriggerMetadata.InstanceId

# Set durable function information for custom Send-DurableExternalEvent
$FunctionsURL = "http://localhost:7071"
$AppCode = "XXX"

function Send-DurableExternalEvent() {
    param (
		[Parameter(Mandatory = $true)]
		[string]$FunctionsURL,

		[Parameter(Mandatory = $true)]
		[string]$InstanceId,
		
		[Parameter(Mandatory = $true)]
		[string]$AppCode,
		
		[Parameter(Mandatory = $true)]
		[string]$EventName,

		[Parameter(Mandatory = $false)]
		[object]$EventDataJson
	)

    $EventURL = ("{0}/runtime/webhooks/durabletask/instances/{1}/raiseEvent/{2}?code={3}" -f $FunctionsURL, $InstanceId, $EventName, $AppCode)

    try {
        $null = Invoke-WebRequest -Method POST -Uri $EventURL -body $EventDataJson -ContentType 'application/json' -Headers @{"accept" = "application/json" }
        Write-Host "Send-DurableExternalEvent success"
    }
    catch {
        Write-Host "Send-DurableExternalEvent failed"
    }
    
}

Write-Host "Trigger event 1"
Send-DurableExternalEvent -FunctionsURL $FunctionsURL -InstanceId $InstanceId -AppCode $AppCode "TESTEVENTNAME" -EventDataJson "{'event': 'first event'}"
Start-Sleep 2

Write-Host "Trigger event 2"
Send-DurableExternalEvent -FunctionsURL $FunctionsURL -InstanceId $InstanceId -AppCode $AppCode "TESTEVENTNAME2" -EventDataJson "{'event': 'second event'}"
Start-Sleep 4

Write-Host "Hello finished"

@davidmrdavid I have created a fork and commit here https://github.com/oobegreg/azure-functions-powershell-worker/tree/3160e043732836c8f6af7d9e76ce7a9e9186d390 as I wasn't sure how to properly contribute to this repo.

It contains the updated Send-DurableExternalEvent function to handle the Azure Functions app code when deployed to Azure.
It also contains updated logic to support event triggers and a new command Get-DurableTaskResult.

Hopefully this helps and could be deployed to Azure as soon as possible.

[amazingidiot]

Thank you a lot for the information!

@ConnorMcMahon @davidmrdavid Happy new year.
Are you able to provide any timeframes on when this might (or an appropriate fix) may be pushed to Azure production?
I need to understand the impacts for our production deployment capabilities.

Thank you

[davidmrdavid]

Hi @oobegreg,

Thank you for reaching out. I'll bring this up for triaging today and I should be able to get back to you with an update, apologies for our delay here.

cc/ @AnatoliB, for context.

[davidmrdavid]

Hi @oobegreg,

I want to make sure we have the same starting context: when using the -Any flag, the result of a Wait-DurableTask should return a Task object instead of the result. You pointed this out in your description, but I wanted to make sure we were in the same page on this being the intended behavior :) .

With that in mind, the missing step would then be to obtain the result data from within that Task. I haven't managed to test this yet, but I would have expected that calling Wait-DurableTask again on that object should yield the result. I do realize we should have a better means of doing this, I'm still exploring whether that already exists in the codebase.

If using Wait-DurableTask on the task object doesn't work, then I do think we should incorporate your Get-DurableTaskResult command, or something very much like it.

@oobegreg: had you tried using Wait-DurableTask on the result of Wait-DurableTask with -Any? Did that work for you?

As for a timeline for a fix, I think the earliest I could merge a fix would be around Wednesday next week. After that, we're tied to the release schedule of the PowerShell Azure Functions worker, and that can take a few weeks. That's why I want to first explore whether there are any means of extracting this result from within the existing codebase as well; it can be a fair wait otherwise.

Hi @davidmrdavid,

Thanks for the quick response and assistance. Not only is it great, it's very much appreciated too.

I think using the -Any flag with Wait-DurableTask should return a task. That way it's easy to determine which task responded by the statement if ($CompleteRunningTask -eq $DurableTimeoutEvent) {.

Thanks for trying to find alternative options in the existing code too. I tried Wait-DurableTask again after the initial call with Any and it crashes (I assume it crashes as the code doesn't continue, but there's no error).

I modified the example code above to look like the following. In the console output I see OUTPUT 1 returned on the log, but nothing after that.

if ($CompleteRunningTask -eq $ParallelActivity) {
        Write-Host "Activity Complete"
        Write-Host "OUTPUT 1"
        $ActivityResults = Wait-DurableTask -Task @($ParallelActivity)

        Write-Host "OUTPUT 2"
        Write-Host ($ActivityResults.GetType())
        Write-Host ($ActivityResults | ConvertTo-Json -Depth 100)
        Write-Host "OUTPUT 3"

        # Write-Host $(Get-DurableTaskResult -Task @($CompleteRunningTask) | ConvertTo-Json -Depth 100)
        $ActivityComplete = $true
        Stop-DurableTimerTask -Task $DurableTimeoutEvent
    }

I also tried Wait-DurableTask -Task $ParallelActivity for good measure.

I think it's not working because the task is already marked as processed/played and no longer returned when Wait-DurableTask is called again (and by extension GetCompletedHistoryEvent).

internal override HistoryEvent GetCompletedHistoryEvent(OrchestrationContext context, HistoryEvent taskScheduled, bool processed)
        {
            return context.History.FirstOrDefault(
                    e => e.EventType == HistoryEventType.EventRaised &&
                         e.Name == ExternalEventName &&
                         e.IsPlayed == processed);
        }

Just an FYI, I tried this with both the modified and production 4.0.1.16815 codeset to be sure.

Is it's possible to include an update to Send-DurableExternalEvent as well (also part of my commit) to ensure that function works in Azure? If so, that would be amazing.

Those suggested timeframes are great too.

Thanks again,
Greg

Hi @davidmrdavid have you been able to progress this? Thanks