How does the consumer commit offset in different modes?

In Go, when working with Kafka, consumer offsets can be committed in different modes, which affect delivery guarantees and performance:

• Auto Commit: offset is committed automatically at a set interval. This is convenient but can lead to message reprocessing on failures.

• Manual Synchronous Commit: after processing a message, a commit method is called, which blocks until confirmation. It guarantees that the offset is saved but reduces performance.

• Manual Asynchronous Commit: offset is committed in the background without blocking processing. Faster, but commit loss can occur on failure.

Example of manual commit using the sarama library:

consumer.MarkMessage(msg, "") // Mark message as processed
err := consumer.CommitOffsets() // Synchronous commit
if err != nil {
    // handle error
}

The choice of mode depends on reliability and performance requirements.