What are Azure Event Hubs?

Azure Event Hubs is a highly scalable data streaming platform and event ingestion service. It can capture, transform, and store millions of events per second. Applications and services that generate large amounts of data can send that data to an event hub, which can then be processed by multiple downstream applications.

Azure Event Hubs Architecture Diagram

Figure 1: Azure Event Hubs High-Level Architecture

Key Concepts

Events

An event is a lightweight piece of information representing something that has happened in the system. Events are immutable records that are appended to an event hub.

Producers

Producers are applications or services that send event data to an Azure Event Hub. These can be IoT devices, web servers, mobile applications, or any other source of real-time data.

Consumers

Consumers are applications or services that read and process event data from an Event Hub. Consumers can work independently of each other, allowing for diverse processing scenarios.

Consumer Groups

A consumer group is a unique view of the data in an event hub. Each consumer group allows an application to independently consume from the event hub without impacting other consumer groups.

Partitions

Event Hubs organizes event streams into partitions. Partitions are ordered sequences of events. They enable parallelism and distributed processing of event streams. Producers can specify a partition key to ensure that events with the same key go to the same partition. If no partition key is specified, Event Hubs assigns events to partitions in a round-robin fashion.

Throughput Units (TUs)

Throughput units are the primary unit of provisioned throughput for Event Hubs. A TU provides a specific amount of ingress and egress capacity. You can scale your Event Hubs namespace by adjusting the number of TUs.

Use Cases

  • Real-time analytics: Process and analyze streaming data from various sources to gain immediate insights.
  • Decoupling applications: Act as a buffer between event producers and consumers, allowing them to operate independently.
  • Big data streaming: Ingest massive volumes of data from IoT devices, log files, and applications for further processing.
  • Event-driven architectures: Enable microservices and other systems to react to events as they happen.

Benefits

  • High Throughput: Handles millions of events per second.
  • Scalability: Scales automatically or manually based on demand.
  • Durability: Data is durably stored and can be replayed.
  • Low Latency: Processes events in near real-time.
  • Integration: Integrates seamlessly with other Azure services like Azure Stream Analytics, Azure Functions, and Azure Databricks.
Note: Event Hubs is designed for high-throughput, low-latency ingestion and processing of streaming data. For scenarios requiring message queuing or guaranteed delivery of individual messages with complex ordering, consider Azure Service Bus.

Getting Started

To start using Azure Event Hubs, you typically need to:

  1. Create an Azure Event Hubs namespace.
  2. Create an event hub within the namespace.
  3. Configure producers to send events to the event hub.
  4. Configure consumer groups and consumers to read events from the event hub.

You can interact with Event Hubs using various SDKs (e.g., .NET, Java, Python, Node.js) or via the Azure portal and Azure CLI.

For detailed tutorials and code samples, refer to the following resources: