Options for auto.offset.reset in Kafka

The default value of the auto.offset.reset configuration in Apache Kafka depends on the context in which it is used. This configuration determines what the consumer should do when there is no initial offset in Kafka or if the current offset does not exist anymore (e.g., due to log cleanup).

Default Value

• latest is the default value for auto.offset.reset.

Options for auto.offset.reset

1. earliest:

   • The consumer starts reading from the beginning of the log (the earliest offset).
   • Useful for reprocessing data from the start.

2. latest (default):

   • The consumer starts reading from the end of the log (the latest offset).
   • It reads only new messages produced after the consumer has started.

3. none:

   • Throws an exception if no offset is found for the consumer's group.
   • Typically used when you want strict control over offsets.

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Example Configuration

Java Code

Properties props = new Properties();
props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");

application.yml for Spring Kafka

spring:
  kafka:
    consumer:
      auto-offset-reset: earliest

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Use Cases for Different Values

• earliest:

  • Data recovery or reprocessing.
  • Analytics jobs where you want to process all available data.

• latest (default):

  • Stream processing where only new data is relevant.
  • Reduces latency as it avoids reprocessing historical messages.

• none:

  • Scenarios where offsets must be explicitly managed or restored.

If you'd like help configuring auto.offset.reset for your use case, let me know!