Kafka Connect Distributed mode The group coordinator is not available

After writing a connector in Go, I came across the same issue. I was forced to solve it myself.

When a connector connects to kafka it automatically writes to the topics and to __offset_topics. When a connector crashes, it leaves trace of itself in those tables as the coordinator. When a new connector starts up it finds the record in the table and attempts to communicate with the coordinator. The coordinator fails to respond and the connector never works.

You can fix this one of two ways, Delete all the topics (connect-configs, connect-offsets, connect-status, __offset_topics) and restart the cluster. The other method is to remove the coordinator from the topics, which I am currently unsure how to perform.

Posting for others who might find it useful.

I had the same problem... and restarting kafka solved the problem in my case.

After executing:

service kafka status

Made my log to be fine in less than 10 seconds:

2019-11-08 14:30:19.781  INFO [-,,,] 1 --- [org.springframework.kafka.KafkaListenerEndpointContainer#0-0-C-1] o.a.k.c.c.internals.AbstractCoordinator  : [Consumer clientId=consumer-2, groupId=datasources-ca-contacts] Discovered group coordinator myserver:9092 (id: 2147483647 rack: null)