Event Ingestion with Azure Event Hubs

This section covers the essential methods and considerations for sending events to Azure Event Hubs. Efficient and reliable event ingestion is crucial for building scalable and responsive applications.

Methods of Event Ingestion

Azure Event Hubs supports several protocols and SDKs for sending events. The choice often depends on your application's requirements, programming language, and existing infrastructure.

1. Using Azure SDKs

The official Azure SDKs provide robust and idiomatic ways to interact with Event Hubs. They offer abstractions for handling connections, batching, retries, and error management.

Here's a simplified example using the Python SDK:


from azure.eventhub import EventHubProducerClient, EventData

# Replace with your connection string and hub name
eventhub_connection_str = "Endpoint=sb://.servicebus.windows.net/;SharedAccessKeyName=;SharedAccessKey="
eventhub_name = ""

producer = EventHubProducerClient.from_connection_string(
    eventhub_connection_str, eventhub_name
)

events = [
    EventData("Event 1 payload"),
    EventData("Event 2 payload"),
    EventData("Event 3 payload"),
]

try:
    with producer:
        # Send events in batches
        batch_properties = producer.create_batch()
        for event in events:
            try:
                batch_properties.add(event)
            except Exception as e:
                print(f"Failed to add event to batch: {e}")
                # Handle event that is too large for batch

        producer.send_batch(batch_properties)
        print("Events sent successfully!")

except Exception as e:
    print(f"Error sending events: {e}")

2. Using AMQP 1.0

Event Hubs is built on the AMQP 1.0 protocol. You can use any AMQP 1.0 client library to send events directly. This offers flexibility if you're not using Azure SDKs or need fine-grained control over the protocol.

Popular AMQP 1.0 client libraries include:

When using AMQP, you'll need to establish a link to the Event Hub and send messages to the appropriate destination.

3. Using HTTP/REST API

For simpler scenarios or when SDKs are not available, you can send events via HTTP POST requests to the Event Hubs REST endpoint. This typically involves authentication using Shared Access Signatures (SAS) or Azure Active Directory (AAD).

The endpoint for sending events is generally:

https://.servicebus.windows.net//messages?api-version=2014-01

Requests must include an Authorization header with a valid SAS token.

Key Considerations for Ingestion

Batching

Sending events individually can be inefficient and increase costs. Event Hubs supports batching, where multiple events are grouped into a single request. This reduces overhead and improves throughput. SDKs often provide automatic batching capabilities.

Partitioning

Event Hubs distributes events across partitions. To ensure ordering within a partition, you can specify a partition key when sending an event. Events with the same partition key are routed to the same partition. If no key is specified, Event Hubs assigns a partition.

Choosing an appropriate partition key is essential for:

Common partitioning strategies include using a user ID, device ID, or a geographical identifier.

Serialization

Events can be sent in various formats, such as JSON, Avro, or plain text. Ensure that your producer and consumer agree on the serialization format. For complex data structures, consider using schema registries.

Error Handling and Retries

Network issues or transient service errors can occur during ingestion. Implement robust error handling and retry mechanisms. Azure SDKs typically include built-in retry policies. For custom implementations, use exponential backoff strategies.

Tip: Leverage the built-in retry policies of the Azure SDKs for Event Hubs. They are designed to handle common transient failures effectively.

Compression

For large volumes of data, consider using compression to reduce network bandwidth and storage costs. Event Hubs supports Gzip and Deflate compression. The SDKs can often handle this automatically or provide options to enable it.

Advanced Topics

Schema Registry Integration

For robust data governance, integrate Event Hubs with a schema registry (like Azure Schema Registry) to manage event schemas and enforce data contracts between producers and consumers.

Producer Throughput Limits

Be aware of the throughput limits for your Event Hubs tier. Exceeding these limits can result in throttling. Monitor your producer metrics and adjust batch sizes or the number of producers as needed.

Warning: If your producer is consistently throttled, it might indicate an issue with your partitioning strategy or that you need to scale up your Event Hubs capacity.

Next Steps

Now that you understand event ingestion, explore how to process these events effectively: