What kind of delivery guarantee this consumer offers?

What kind of delivery guarantee this consumer offers?

while (true) {

ConsumerRecords<String, String> records = consumer.poll(100);

try {

consumer.commitSync();

} catch (CommitFailedException e) { log.error("commit failed", e)

}

for (ConsumerRecord<String, String> record records)

{

System.out.printf("topic = %s, partition = %s, offset = %d, customer = %s, country = %s

",

record.topic(), record.partition(), record.offset(), record.key(), record.value());

}

}
A . Exactly-once
B . At-least-once
C . At-most-once

View Answer

Answer: C

Explanation:

Here offset is committed before processing the message. If consumer crashes before processing the message, message will be lost when it comes back up.