Introducing the Kafka Consumer: Getting Started with the New Apache Kafka 0.9 Consumer Client | Confluent

This post introduces the new Apache Kafka 0.9 consumer client, detailing its advantages over previous clients: a consolidated API, reduced dependencies (pure Java, no ZooKeeper), and better security support. It explains the new group coordination protocol, group coordinator role, rebalancing process, and the concepts of committed offsets, consumer position, log end offset, and high watermark. The post provides code examples for configuration, topic subscription, and the basic poll loop, including error handling with `WakeupException` and the importance of closing the consumer. It also highlights the beta status of the new consumer at the time of writing and encourages bug reporting.