Azure Event Hubs client library for .NET - version 4.3.2

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Please note, a newer package Azure.Messaging.EventHubs for Azure Event Hubs is available as of February 2020. While this package will continue to receive critical bug fixes, we strongly encourage you to upgrade. Read the migration guide for more details.

Azure Event Hubs is a highly scalable publish-subscribe service that can ingest millions of events per second and stream them into multiple applications. This lets you process and analyze the massive amounts of data produced by your connected devices and applications. Once Event Hubs has collected the data, you can retrieve, transform and store it by using any real-time analytics provider or with batching/storage adapters.

The Azure Events Hubs client library for .NET allows for both sending and receiving of events. Most common scenarios call for an application to act as either an event publisher or an event consumer, but rarely both.

An event publisher is a source of telemetry data, diagnostics information, usage logs, or other log data, as part of an embedded device solution, a mobile device application, a game title running on a console or other device, some client or server based business solution, or a web site.

An event consumer picks up such information from the Event Hub and processes it. Processing may involve aggregation, complex computation and filtering. Processing may also involve distribution or storage of the information in a raw or transformed fashion. Event Hub consumers are often robust and high-scale platform infrastructure parts with built-in analytics capabilities, like Azure Stream Analytics, Apache Spark, or Apache Storm.

This directory contains the open source subset of the .NET SDK. For documentation of the complete Azure SDK, please see the Microsoft Azure .NET Developer Center.

Use the client library for Event Hubs to:

  • Emit telemetry about your application for business intelligence and diagnostic purposes.

  • Publish facts about the state of your application which interested parties may observe and use as a trigger for taking action.

  • Observe interesting operations and interactions happening within your business or other ecosystem, allowing loosely coupled systems to interact without the need to bind them together.

  • Receive events from one or more publishers, transform them to better meet the needs of your ecosystem, then publish the transformed events to a new stream for consumers to observe.

Source code | Package (NuGet) | API reference documentation | Product documentation

Getting started

The complete Microsoft Azure SDK can be downloaded from the Microsoft Azure Downloads Page and ships with support for building deployment packages, integrating with tooling, rich command line tooling, and more.

If you are not already familiar with Azure Event Hubs, please review: What is Event Hubs?.

For the best development experience, developers should use the official Microsoft NuGet packages for libraries. NuGet packages are regularly updated with new functionality and hotfixes.

Prerequisites

  • Microsoft Azure Subscription: To call Microsoft Azure services, including Azure Event Hubs, you need to first create an account. If you do not have an existing Azure account, you may sign up for a free trial or use your MSDN subscriber benefits.

  • The Azure Event Hubs client library shares the same Prerequisites as the Microsoft Azure SDK for .NET.

Samples

Code samples for the Azure Event Hubs client library that detail how to get started and how to implement common scenarios can be found in the following locations:

To build

For information on building the Azure Event Hubs client library, please see Building the Microsoft Azure SDK for .NET

Running tests

The Event Hubs client library tests may be executed using the dotnet CLI, or the test runner of your choice - such as Visual Studio or Visual Studio Code. For those developers using Visual Studio, it is safe to use the Live Unit Testing feature, as any tests with external dependencies have been marked to be excluded.

Tests in the Event Hubs client library are split into two categories:

  • Unit tests have no special considerations; these are self-contained and execute locally without any reliance on external resources. Unit tests are considered the default test type in the Event Hubs client library and, thus, have no explicit category trait attached to them.

  • Integration tests have dependencies on live Azure resources and require setting up your development environment prior to running. Known in the Azure SDK project commonly as "Live" tests, these tests are decorated with a category trait of "LiveTest". To run them, an Azure resource group and Azure Service Principal with "contributor" rights to that resource group are required. For each test run, the Live tests will use the service principal to dynamically create an Event Hubs namespace and Azure Storage account within the resource group and remove them once the test run is complete.

The Live tests read information from the following environment variables:

EVENTHUB_RESOURCE_GROUP
The name of the Azure resource group that contains the Event Hubs namespace

EVENTHUB_SUBSCRIPTION_ID
The identifier (GUID) of the Azure subscription to which the service principal belongs

EVENTHUB_TENANT_ID
The identifier (GUID) of the Azure Active Directory tenant that contains the service principal

EVENTHUB_CLIENT_ID
The identifier (GUID) of the Azure Active Directory application that is associated with the service principal

EVENTHUB_CLIENT_SECRET
The client secret (password) of the Azure Active Directory application that is associated with the service principal

To make setting up your environment easier, a PowerShell script is included in the repository and will create and/or configure the needed Azure resources. To use this script, open a PowerShell instance and login to your Azure account using Login-AzAccount, then execute the script. You will need to provide some information, after which the script will configure the Azure resources and then output the set of environment variables with the correct values for running tests.

The simplest way to get started is to execute the script with your subscription name and then follow the prompts:

./live-tests-azure-setup -SubscriptionName "<< YOUR SUBSCRIPTION NAME >>"

Help for the full set of parameters and additional information is available by specifying the -Help flag.

./live-tests-azure-setup -Help

Development history

For additional insight and context, the development, release, and issue history for the Azure Event Hubs client library will continue to be available in read-only form, located in the stand-alone Azure Event Hubs .NET repository.

Versioning information

The Azure Event Hubs client library uses the semantic versioning scheme.

Target frameworks

For information about the target frameworks of the Azure Event Hubs client library, please refer to the Target Frameworks of the Microsoft Azure SDK for .NET.

Contributing

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact opencode@microsoft.com with any additional questions or comments.

Additional documentation

Impressions