Sending Data to Azure Event Hubs

This guide will walk you through the various methods and best practices for sending data to Azure Event Hubs. Event Hubs is a highly scalable data streaming platform and event ingestion service. It can capture millions of events per second so that you can process and analyze them in real time or in batches.

Prerequisites

Before you begin, ensure you have the following:

Methods for Sending Data

1. Using Azure SDKs

The most common and recommended way to send data is by using the official Azure SDKs. These SDKs provide language-specific libraries that abstract away the complexities of the underlying protocols.

Example (Python):


from azure.eventhub import EventHubProducerClient, EventData

# Replace with your actual connection string and event hub name
connection_str = "YOUR_EVENTHUB_CONNECTION_STRING"
event_hub_name = "YOUR_EVENTHUB_NAME"

producer = EventHubProducerClient.from_connection_string(connection_str, event_hub_name=event_hub_name)

events_to_send = [
    EventData("This is event 1"),
    EventData("This is event 2"),
    EventData({"key": "value", "number": 123})
]

try:
    # Send events in batches
    with producer:
        producer.send_batch(events_to_send)
    print("Events sent successfully!")
except Exception as e:
    print(f"An error occurred: {e}")

Example (Java):


import com.azure.messaging.eventhubs.EventHubProducerClient;
import com.azure.messaging.eventhubs.EventHubClientBuilder;
import com.azure.messaging.eventhubs.models.CreateBatchOptions;
import com.azure.messaging.eventhubs.models.SendOptions;
import com.azure.messaging.eventhubs.models.EventHubEvent;
import java.util.Arrays;

public class EventHubSender {

    public static void main(String[] args) {
        // Replace with your actual connection string and event hub name
        String connectionString = "YOUR_EVENTHUB_CONNECTION_STRING";
        String eventHubName = "YOUR_EVENTHUB_NAME";

        EventHubProducerClient producer = new EventHubClientBuilder()
            .connectionString(connectionString)
            .eventHubName(eventHubName)
            .buildProducerClient();

        try {
            // Create an event batch
            CreateBatchOptions options = new CreateBatchOptions();
            // You can set max size if needed:
            // options.setMaxSizeInBytes(EventHubProducerClient.MAX_MESSAGE_SIZE_IN_BYTES);

            // Send individual events with partition key
            producer.send(Arrays.asList(
                new EventHubEvent("Event 1".getBytes()),
                new EventHubEvent("Event 2".getBytes())
            ), new SendOptions().setPartitionKey("partitionKey1"));

            System.out.println("Events sent successfully!");

        } catch (Exception e) {
            System.err.println("An error occurred: " + e.toString());
        } finally {
            producer.close();
        }
    }
}

Tip: Batching Events

For improved performance and efficiency, it's recommended to batch your events before sending them. SDKs typically provide methods for creating and sending event batches.

2. Using AMQP or Kafka Protocols Directly

Event Hubs supports AMQP 1.0 and Kafka protocols. You can use compatible clients for these protocols to send data, although using the official SDKs is generally simpler and provides better integration with Azure services.

AMQP 1.0

You can use libraries like qpid-proton-python or Apache Qpid Proton-J to interact with Event Hubs over AMQP.

Kafka Compatibility

Event Hubs offers Kafka compatibility. If you have existing Kafka producers, you can often configure them to send data to your Event Hub by using the Event Hubs endpoint as the Kafka bootstrap server.

For Kafka, the bootstrap server format is typically:

<your-eventhub-namespace>.servicebus.windows.net:9093

You will also need to provide SASL credentials.

Key Concepts for Sending Data

Partitioning

Event Hubs distributes events across multiple partitions. When sending data, you can influence which partition an event lands in by specifying a Partition Key.

Partition Key Strategy

Choosing an effective partition key is crucial for load balancing and ordering. Common strategies include using a device ID, user ID, or session ID.

Message Content

Event Hubs events are essentially byte arrays. You can serialize your data into JSON, Avro, Protobuf, or any other format before sending it.

Note on Message Size

Each message sent to Event Hubs has a maximum size limit. Refer to the Azure Event Hubs documentation for the most current limits. Ensure your batches and individual messages adhere to these limits.

Best Practices