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What is wrong with this Kafka consumer code that causes it to never print messages?

medium📝 Debug Q7 of Q15

Kafka - with Java/Python

What is wrong with this Kafka consumer code that causes it to never print messages?

consumer = KafkaConsumer('topic2', bootstrap_servers='localhost:9092', auto_offset_reset='latest')
for message in consumer:
    print(message.value.decode())

Aauto_offset_reset='latest' skips existing messages

BMissing call to consumer.poll()

Cdecode() should be called on message.key

Dbootstrap_servers is incorrect parameter

Step-by-Step Solution

Solution:

Step 1: Understand auto_offset_reset='latest'
This setting makes the consumer start reading only new messages after it starts.
Step 2: No new messages means no output
If no new messages arrive, the loop never prints anything.
Final Answer:
auto_offset_reset='latest' skips existing messages -> Option A
Quick Check:
auto_offset_reset='latest' reads only new messages [OK]

Quick Trick: auto_offset_reset='latest' skips old messages [OK]

Common Mistakes:

MISTAKES

Expecting poll() call is mandatory
Decoding message.key instead of value
Misnaming bootstrap_servers

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