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Event Hubs

Ingest high-throughput event streams with Event Hubs triggers and output bindings in PowerShell.

Event Hub Trigger

function.json:

{
  "bindings": [
    {
      "name": "Events",
      "type": "eventHubTrigger",
      "direction": "in",
      "eventHubName": "telemetry",
      "connection": "EventHubConnection",
      "cardinality": "many",
      "consumerGroup": "$Default"
    }
  ]
}

run.ps1:

param($Events, $TriggerMetadata)

Write-Information "Received batch of $($Events.Count) event(s)"
foreach ($event in $Events) {
    Write-Information "Event body: $event"
}

With cardinality set to many, the trigger delivers events as an array for efficient batch processing. Use one only for low-volume debugging.

Accessing Event Metadata

The $TriggerMetadata object exposes per-event system properties such as PartitionContext, EnqueuedTimeUtc, and SequenceNumber:

Write-Information "Partition: $($TriggerMetadata.PartitionContext.PartitionId)"

Output Binding

{
  "name": "OutputEvent",
  "type": "eventHub",
  "direction": "out",
  "eventHubName": "processed",
  "connection": "EventHubConnection"
}

Push-OutputBinding -Name OutputEvent -Value (@{ deviceId = "sensor-01"; value = 42 } | ConvertTo-Json)

Checkpoint and scaling

Event Hubs triggers checkpoint per partition. A slow function increases checkpoint lag and delays scaling. Keep per-event work minimal and offload heavy processing.

See Also

Sources