Q:

kafka mongodb sink connector not starting

I've installed confluent_3.3.0 and started zookeper, schema-registry and kafka broker.  I have also downloaded mongodb connector from this link. 
Description: I'm running sink connector using the following command:
./bin/connect-standalone etc/kafka/connect-standalone.properties /home/username/mongo-connect-test/kafka-connect-mongodb/quickstart-couchbase-sink.properties
Problem: I'm getting the following error:
ERROR Stopping after connector error (org.apache.kafka.connect.cli. ConnectStandalone:91)
java.lang. IllegalAccessError: tried to access field org.apache.kafka.common.config. ConfigDef. NO_DEFAULT_VALUE from class org.radarcns.mongodb. MongoDbSinkConnector

Thanks for reading ! 

A:

This connector is using, at its latest version, an old version of the kafka-clients API.  Specifically, it is depending on a constructor of the class org.apache.kafka.common.config. AbstractConfig that does not exist in Apache Kafka versions >= 0.11.0.0
Confluent Platform version 3.3.0 is using Apache Kafka 0.11.0.0
To fix this issue, the recommended approach would be to update the connector code to use the most recent versions of Apache Kafka APIs. 