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

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.

RetriableException is a subclass of KafkaException, indicating transient issues thatmight succeed if retried. Examples include:

LeaderNotAvailableException: Happens when metadata is not yet propagated or leader election is in progress.

NotEnoughReplicasException: Happens when the number of in-sync replicas is insufficient. This can be transient if replicas come back online.

From theApache Kafka Java Client documentation:

"These exceptions (like LeaderNotAvailableException, NotEnoughReplicasException) are transient and the client will retry them automatically depending on retry configuration."

RecordTooLargeExceptionandAuthorizationExceptionarenon-retriableas they indicate client-side or permission errors.

In Kafka Streams,the number of stream tasks = number of input partitions × num.stream.threads × number of instances,but only as many as the number of partitions can actively consume at once.

However, in this case,Kafka Streams assigns one task per partition, and because there are 5 partitions and 15 threads (3 instances × 5 threads),15 tasks are created, andall 15 can be activedepending on processing topology.

FromKafka Streams Developer Guide:

"Kafka Streams creates one task per input partition. If you increase the number of stream threads, it runs multiple tasks in parallel within a single instance."

So,15 stream tasks will be created and 15 will be actively consuming.