The leastLoadedNode() function in kafka-client may choose a faulty node during the consumer thread starting and meanwhile one of the KAFKA server node is dead.

The leastLoadedNode() function has a bug during the consumer process starting period. The function sendMetadataRequest() called by getTopicMetadataRequest() uses a random node which maybe faulty since every node‘s state recorded in the client thread is not ready yet. It happened in my production environment during my consumer thread restarting and meanwhile one of the KAFKA server node is dead. Then the client startup failed. 

I'm using the kafka-client-2.0.1.jar. I have checked the source code of higher versions and the issue still exists.