Non-Blocking Retries

Version 2.9 changed the mechanism to bootstrap infrastructure beans; see Configuration for the two mechanisms that are now required to bootstrap the feature.

Achieving non-blocking retry / dlt functionality with Kafka usually requires setting up extra topics and creating and configuring the corresponding listeners. Since 2.7 Spring for Apache Kafka offers support for that via the @RetryableTopic annotation and RetryTopicConfiguration class to simplify that bootstrapping.