feat(outputs.event_hubs): Expose max message size batch option (#11991)

plugins/outputs/event_hubs/README.md

@@ -31,6 +31,12 @@ JSON is probably the easiest to integrate with downstream components.
   ## and field, exist the tag is preferred.
   # partition_key = ""
 
+  ## Set the maximum batch message size in bytes
+  ## The allowable size depends on the Event Hub tier
+  ## See: https://learn.microsoft.com/azure/event-hubs/event-hubs-quotas#basic-vs-standard-vs-premium-vs-dedicated-tiers
+  ## Setting this to 0 means using the default size from the Azure Event Hubs Client library (1000000 bytes)
+  # max_message_size = 1000000
+
   ## Data format to output.
   ## Each data format has its own unique set of configuration options, read
   ## more about them here:

plugins/outputs/event_hubs/event_hubs.go

@@ -58,9 +58,11 @@ type EventHubs struct {
 	ConnectionString string          `toml:"connection_string"`
 	Timeout          config.Duration `toml:"timeout"`
 	PartitionKey     string          `toml:"partition_key"`
+	MaxMessageSize   int             `toml:"max_message_size"`
 
-	Hub        EventHubInterface
-	serializer serializers.Serializer
+	Hub          EventHubInterface
+	batchOptions []eventhub.BatchOption
+	serializer   serializers.Serializer
 }
 
 const (
@@ -78,6 +80,10 @@ func (e *EventHubs) Init() error {
 		return err
 	}
 
+	if e.MaxMessageSize > 0 {
+		e.batchOptions = append(e.batchOptions, eventhub.BatchWithMaxSizeInBytes(e.MaxMessageSize))
+	}
+
 	return nil
 }
 
@@ -130,7 +136,7 @@ func (e *EventHubs) Write(metrics []telegraf.Metric) error {
 	ctx, cancel := context.WithTimeout(context.Background(), time.Duration(e.Timeout))
 	defer cancel()
 
-	err := e.Hub.SendBatch(ctx, eventhub.NewEventBatchIterator(events...))
+	err := e.Hub.SendBatch(ctx, eventhub.NewEventBatchIterator(events...), e.batchOptions...)
 
 	if err != nil {
 		return err

plugins/outputs/event_hubs/event_hubs_test.go

@@ -49,6 +49,7 @@ func TestInitAndWrite(t *testing.T) {
 		Hub:              mockHub,
 		ConnectionString: "mock",
 		Timeout:          config.Duration(time.Second * 5),
+		MaxMessageSize:   1000000,
 		serializer:       serializer,
 	}
 

plugins/outputs/event_hubs/sample.conf

@@ -13,6 +13,12 @@
   ## and field, exist the tag is preferred.
   # partition_key = ""
 
+  ## Set the maximum batch message size in bytes
+  ## The allowable size depends on the Event Hub tier
+  ## See: https://learn.microsoft.com/azure/event-hubs/event-hubs-quotas#basic-vs-standard-vs-premium-vs-dedicated-tiers
+  ## Setting this to 0 means using the default size from the Azure Event Hubs Client library (1000000 bytes)
+  # max_message_size = 1000000
+
   ## Data format to output.
   ## Each data format has its own unique set of configuration options, read
   ## more about them here: