Kafka Connect - Error while fetching metadata with correlation id UNKNOWN_TOPIC_OR_PARTITION

Question

We have Kafka Connect running a postgres connector it is pulling changes from a DB and putting them into a topic. We are getting an error

ERROR WorkerSourceTask{id=wem-postgres-source-0} Failed to flush, timed out while waiting for producer to flush outstanding 1 messages

followed by

ERROR WorkerSourceTask{id=wem-postgres-source-0} Failed to commit offsets (org.apache.kafka.connect.runtime.SourceTaskOffsetCommitter)

followed by

[2020-01-30 09:51:52,219] WARN [Producer clientId=producer-8] Error while fetching metadata with correlation id 606994 : {topicname=UNKNOWN_TOPIC_OR_PARTITION} (org.apache.kafka.clients.NetworkClient)

We have verified that the topic does exist, doing a describe on the topic give us this

zookeeper-1 [root@XX /bin]# ./kafka-topics --describe --zookeeper <zookeeper>:2181 --topic topicname

Topic:topicname PartitionCount:1    ReplicationFactor:3 Configs:
    Topic: topicname    Partition: 0    Leader: 2   Replicas: 2,3,1 Isr: 3,2,1

Answer 1

ERROR WorkerSourceTask{id=wem-postgres-source-0} Failed to flush, timed out while waiting for producer to flush outstanding 1 messages

and

[2020-01-30 09:51:52,219] WARN [Producer clientId=producer-8] Error while fetching metadata with correlation id 606994 : {topicname=UNKNOWN_TOPIC_OR_PARTITION} (org.apache.kafka.clients.NetworkClient)

are from the same issue. Have you tried reaching your Kafka cluster or upgrading your Kafka? The latest kafka-topics script uses broker hosts instead of ZooKeeper hosts to describe topics.

As for

ERROR WorkerSourceTask{id=wem-postgres-source-0} Failed to commit offsets (org.apache.kafka.connect.runtime.SourceTaskOffsetCommitter)

Make sure that offset.storage.topic of your Kafka Connect has already been created in Kafka. Workers flush offsets into this topic.