Confluent Updated CCDAK Exam Questions and Answers by mohamad

Apache Kafka Connect stores source connector offsets in a Kafka topic defined by the offset.storage.topic configuration. Since this property is explicitly set to connect-offsets, Kafka Connect will commit offsets to that topic, making Option C correct.

The offset.storage.replication.factor controls how many replicas the offsets topic will have. When this value is set to -1, Kafka Connect uses the broker’s default replication factor, as documented in the Kafka Connect worker configuration reference. Therefore, Option A is also correct.

Option B is incorrect because Kafka Connect does not use Kafka’s internal consumer offsets topic (__consumer_offsets). It always uses the configured offsets topic. Option D is incorrect because offset.flush.timeout.ms defines how long Connect will wait for offset commits to complete, not how long it waits before attempting a commit. The commit interval itself is controlled by offset.flush.interval.ms (60 seconds in this case).

Thus, the correct statements that match the expected behavior are A and C.

Correct Matches

path.format→Only valid for some Source Connectors

value.converter→Valid for all Source Connectors

input.path→Only valid for some Source Connectors

errors.retry.timeout→Valid for all Source Connectors

tasks.max→Valid for all Source Connectors

path.formatThis is a connector-specific configuration, commonly used by file-based or storage-based source connectors (for example, HDFS, S3, or FilePulse connectors). It isnot part of the Kafka Connect framework itself, so it is only valid for some source connectors.

value.converterThis is aworker-level configurationthat defines how record values are converted (JSON, Avro, Protobuf, etc.). It applies toall connectorsrunning on the worker unless overridden at the connector level.

input.pathThis configuration is specific to file-based source connectors (e.g., FileStreamSourceConnector). It isnot universally supported, so it is only valid for some source connectors.

errors.retry.timeoutThis is part of Kafka Connect’serror handling framework, introduced to support retries and tolerance of transient errors. It is ageneric Connect configurationand valid for all connectors.

tasks.maxThis is amandatory, generic connector configurationthat controls the maximum number of tasks a connector may create. It is valid forall source (and sink) connectors.

The Apache Kafka monitoring and operations documentation highlights several controller-level metrics that are critical indicators of cluster health.

ActiveControllerCount must always be 1 in a healthy cluster. A value of 0 indicates no active controller, while values greater than 1 indicate a serious split-brain condition. This metric is fundamental for cluster stability.

OfflinePartitionsCount is one of the most important health metrics. Any value greater than 0 means that some partitions have no available leader, making them unavailable for producers and consumers. This directly indicates a degraded or unhealthy cluster.

UncleanLeaderElectionsPerSec tracks the rate of unclean leader elections. Unclean elections can cause data loss, and any non-zero value is a strong signal of broker failures or misconfiguration and should immediately trigger alerts.

The remaining options are not minimum health indicators. LastCommittedRecordOffset is not a standard health metric, and TopicsToDeleteCount only indicates pending administrative operations, not cluster instability.

Therefore, the three minimum and officially recommended broker metrics for monitoring Kafka cluster health are UncleanLeaderElectionsPerSec, ActiveControllerCount, and OfflinePartitionsCount.

SMTs (Single Message Transforms) are lightweight transformations applied to individual messages as they pass through Kafka Connect.

Chaining SMTs: You can apply multiple SMTs in sequence by defining them in order in the connector config.

Masking or modifying fields is a common use case (e.g., redacting sensitive data).

From Kafka Connect Documentation:

“Single Message Transforms (SMTs) are applied to individual messages. You can chain multiple SMTs together.”

SMTs do not perform joins (B is incorrect).

Converters and SMTs are separate concerns (D is incorrect).