CCDAK Exam Dumps : Confluent Certified Developer for Apache Kafka Certification Examination

Kafka Streams usestransactional producersto guaranteeexactly-once semantics (EOS). This ensures that both theoutput recordsandstate store updatesare committed atomically, avoiding duplication or partial writes.

FromKafka Streams Documentation > Processing Guarantees:

“Kafka Streams leveragesKafka’s transactional APIsto commit the output records and internal state updatesas a single atomic unit, thereby providing exactly-once semantics.”

Option A is incorrect because log compaction is not disabled for EOS.

Option C incorrectly describes a checkpointing system Kafka Streams does not use.

Option D refers to deduplication, which is not how EOS is achieved in Streams.

The default maximum message size that a Kafka broker accepts is1MB (1,048,576 bytes), controlled by the config propertymessage.max.bytes.

FromKafka Broker Configuration Docs:

“The default maximum message size is 1MB. To accept larger messages, configure message.max.bytes and the producer’s max.request.size.”

Producers also have a matching limit via max.request.size, and consumers via fetch.message.max.bytes.

These three metrics are critical for cluster health:

OfflinePartitionsCount: Indicates partitions without active leaders — a sign of broker failure.

ActiveControllerCount: There should beexactly one active controller. A count ≠ 1 signals controller failure.

UncleanLeaderElectionsPerSec: Tracks leader elections where out-of-sync replicas were selected — risky for data loss.

FromKafka Monitoring Documentation:

“Offline partitions and unclean leader elections should trigger alerts. Also, ensure a single active controller is running.”

A is about topics pending deletion — not critical.

E is a per-topic record metric, not broker-level.