How does Kafka handle consumer offset on the client side?

In Kafka, the consumer’s offset can be managed in two ways:

1. Manually manage offsets: Consumers can manually commit consumer offsets by calling commitSync or commitAsync methods. This ensures that the offset is committed promptly after processing each message, avoiding issues of duplicate consumption and data loss. Additionally, consumers can use the seek method to reposition the offset, allowing for replaying messages or skipping some messages.
2. Automatic offset management: Kafka offers a feature for managing offset automatically, consumers can enable this feature by setting the enable.auto.commit parameter to true. When automatic offset commit is enabled, Kafka will automatically periodically submit the offset of consumers in the background, consumers do not need to submit manually. However, it is important to note that automatic offset management may result in some messages being consumed multiple times or lost, so caution is advised when using this feature.

In general, consumer-side offsets can be managed manually or automatically, and consumers can choose the appropriate way to manage offsets based on their own needs.