yes I initially did not add ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG` or `ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG. I was getting the same error so tried setting them explicitly.
I did mvn dependency:tree | grep -i kafka. I did not see any other versions of Kafka in non test dependency and this error I am not getting during test but only when I am running my flink application. [INFO] +- org.apache.flink:flink-connector-kafka_2.12:jar:1.13.1:compile [INFO] | +- org.apache.kafka:kafka-clients:jar:2.4.1:compile [INFO] +- org.apache.kafka:kafka_2.12:jar:2.4.1:test [INFO] +- org.apache.flink:flink-connector-kafka_2.12:test-jar:tests:1.13.1:test [INFO] +- net.mguenther.kafka:kafka-junit:jar:2.4.0:test [INFO] | +- org.apache.kafka:kafka_2.11:jar:2.4.0:test [INFO] | +- org.apache.kafka:kafka_2.11:jar:test:2.4.0:test [INFO] | +- org.apache.kafka:kafka-clients:jar:test:2.4.0:test [INFO] | +- org.apache.kafka:connect-api:jar:2.4.0:test [INFO] | +- org.apache.kafka:connect-json:jar:2.4.0:test [INFO] | \- org.apache.kafka:connect-runtime:jar:2.4.0:test [INFO] | +- org.apache.kafka:kafka-tools:jar:2.4.0:test [INFO] | | +- org.apache.kafka:kafka-log4j-appender:jar:2.4.0:test [INFO] | +- org.apache.kafka:connect-transforms:jar:2.4.0:test On Tue, Aug 24, 2021 at 5:08 PM Fabian Paul <fabianp...@ververica.com> wrote: > Hi Debraj, > > The error looks indeed strange. We recommend to not set any > `ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG` > or `ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG` > because the connector will take care of it. Can you try to remove these > call and check if it makes a difference? > > Only looking at the error message it feels like different versions of > the Kafka dependency are on the class path. > > Best, > Fabian >
