We’re excited to announce a new stable release of the Azure Event Hubs library for Java (azure-messaging-eventhubs 5.20.0). Version 5.20.0 integrates the AMQP v2 stack engine, which is the new AMQP (Advanced Message Queuing Protocol) client stack redesigned to improve the reliability and performance of the Azure Messaging libraries.

In September 2024, we introduced the AMQP v2 stack engine as an optional feature for the Event Hubs library with version 5.19.0. Over the past three months, this engine went through stress tests and demonstrated improved reliability for customers who piloted its use.

Additionally, the same AMQP v2 stack engine became the default engine for the Azure Service Bus library starting with version 7.17.1, which was released in June 2024. Service Bus library customers reported improvements in reliability and performance compared to the earlier AMQP v1 stack engine.

The AMQP v2 stack engine brings several key improvements to Azure Messaging libraries:

• Reducing thread hopping, removing locks, optimizing code in hot paths, and reducing memory allocations.
• Resolving multiple race conditions, including those issues related to prefetching and credit calculations.
• Enhancing error handling to improve reliability in the face of transient issues.
• In the Event Hubs library using the AMQP v2 stack, memory usage for receiving events improved by up to ~40% compared to the AMQP v1 stack, with v1 experiencing memory spikes while v2 maintains consistent usage. Additionally, the time taken to send events improved significantly, with event receiving durations averaging ~50% less than the v1 stack.
• The Service Bus library using AMQP v2 stack delivers up to 50% higher throughput for message processor use cases.

Although labeled as v2, customers only need to upgrade the library version without making any modifications to their applications. All updates in the AMQP v2 stack are internal, with no breaking changes to the public APIs.

We’re confident that the Azure Event Hubs library, powered by the AMQP v2 stack engine, delivers an enhanced and seamless experience.

If you encounter any problems, open an issue and refer to the troubleshooting guidelines for log collection instructions.