Kafka Controller could not connect to brokers

Question

I have a 3 node Kafka cluster (version 0.10.1.0). I followed the steps described in the kafka security documentation . Here are the related configurations of one of my Kafka servers.

listeners=SSL://myhostname:9093
security.inter.broker.protocol=SSL
advertised.listeners=SSL://myhostname:9093
# In order to enable hostname verification
ssl.endpoint.identification.algorithm=HTTPS

ssl.client.auth=required

# certificate file locations
ssl.keystore.location=/location/server1.keystore.jks
ssl.keystore.password=changeit
ssl.key.password=changeit
ssl.truststore.location=/location/server.truststore.jks
ssl.truststore.password=changeit

# Supported TLS versions
ssl.enabled.protocols=TLSv1.2,TLSv1.1,TLSv1

I defined 3 different keystores for all my Kafka servers and signed them with the same CA. When I start Kafka servers, the controller log constantly logs the following warning log.

WARN [Controller-0-to-broker-2-send-thread], Controller 0 connection to broker host3:9093 (id: 2 rack: null) was unsuccessful (kafka.controller.RequestSendThread)
java.io.IOException: Connection to host3:9093 (id: 2 rack: null) failed
    at kafka.utils.NetworkClientBlockingOps$.awaitReady$1(NetworkClientBlockingOps.scala:83)
    at kafka.utils.NetworkClientBlockingOps$.blockingReady$extension(NetworkClientBlockingOps.scala:93)
    at kafka.controller.RequestSendThread.brokerReady(ControllerChannelManager.scala:230)
    at kafka.controller.RequestSendThread.liftedTree1$1(ControllerChannelManager.scala:182)
    at kafka.controller.RequestSendThread.doWork(ControllerChannelManager.scala:181)
    at kafka.utils.ShutdownableThread.run(ShutdownableThread.scala:63)
WARN [Controller-0-to-broker-0-send-thread], Controller 0 connection to broker host1:9093 (id: 0 rack: null) was unsuccessful (kafka.controller.RequestSendThread)
java.io.IOException: Connection to host1:9093 (id: 0 rack: null) failed
    at kafka.utils.NetworkClientBlockingOps$.awaitReady$1(NetworkClientBlockingOps.scala:83)
    at kafka.utils.NetworkClientBlockingOps$.blockingReady$extension(NetworkClientBlockingOps.scala:93)
    at kafka.controller.RequestSendThread.brokerReady(ControllerChannelManager.scala:230)
    at kafka.controller.RequestSendThread.liftedTree1$1(ControllerChannelManager.scala:182)
    at kafka.controller.RequestSendThread.doWork(ControllerChannelManager.scala:181)
    at kafka.utils.ShutdownableThread.run(ShutdownableThread.scala:63)
WARN [Controller-0-to-broker-1-send-thread], Controller 0 connection to broker host2:9093 (id: 1 rack: null) was unsuccessful (kafka.controller.RequestSendThread)
java.io.IOException: Connection to host2:9093 (id: 1 rack: null) failed
    at kafka.utils.NetworkClientBlockingOps$.awaitReady$1(NetworkClientBlockingOps.scala:83)
    at kafka.utils.NetworkClientBlockingOps$.blockingReady$extension(NetworkClientBlockingOps.scala:93)
    at kafka.controller.RequestSendThread.brokerReady(ControllerChannelManager.scala:230)
    at kafka.controller.RequestSendThread.liftedTree1$1(ControllerChannelManager.scala:182)
    at kafka.controller.RequestSendThread.doWork(ControllerChannelManager.scala:181)
    at kafka.utils.ShutdownableThread.run(ShutdownableThread.scala:63)

It seems to me more serious than a warning.

Do you have any ideas what might be the problem?

Thanks in advance.

Answer 1

, . . :

, (CN) (FQDN) . CN DNS-, , , .

!