Azure Durable Function loses input on retry - powershell

Question

When I retry unsuccessful operation using Powershell Durable Functions, it throws this exception:
HTTP Trigger script:
using namespace System.Net
param($Request, $TriggerMetadata)
$Request
$FunctionName = $Request.Params.FunctionName
$body = $Request.Body
$InstanceId = Start-NewOrchestration -FunctionName $FunctionName -Input $body
Orchestrator:
param($Context)
$data = $Context.input
Invoke-ActivityFunction -FunctionName 'O365_Holds_Activity' -Input $data
Activity Trigger:
using namespace System.Net
param([System.Collections.Hashtable] $message)
...
And function.json
{
"bindings": [
{
"name": "message",
"type": "activityTrigger",
"direction": "in"
}
],
"retry": {
"strategy": "fixedDelay",
"maxRetryCount": 3,
"delayInterval": "00:00:5"
}
}
First run has no problem with input, but the second one throws such exception. Btw, http request example:
HTTP POST: http://localhost:7071/api/orchestrators/O365_Orchestrator
Body:
{
"holdIds": [
1
],
"action": 0
}

Answer 1

In Durable orchestrators, I would recommend using the Durable-specific retry feature instead of the generic retry policies preview feature, for example:
$retryOptions = New-DurableRetryOptions `
-FirstRetryInterval (New-Timespan -Seconds 5) `
-MaxNumberOfAttempts 3
Invoke-DurableActivity -FunctionName $FunctionName -RetryOptions $retryOptions
The advantage of this approach is that the orchestration state gets persisted between retries, which eliminates the risk of the orchestrator invocation timing out because of retries, and make your orchestration more robust in general.