Not working Confluent Platform 6.1.4 version


Last time I decided to upgrade Confluent Platform version in my Docker cluster. Unfortunatelly I got following logs output in “latest” (7.2.1) CP Kafka container:

22 [main] INFO org.apache.zookeeper.common.X509Util  - Setting -D jdk.tls.rejectClientInitiatedRenegotiation=true to disable client-initiated TLS renegotiation
Exception in thread "main" java.lang.NoClassDefFoundError: io/netty/channel/ChannelHandler
        at java.base/java.lang.Class.forName0(Native Method)
        at java.base/java.lang.Class.forName(
        at org.apache.zookeeper.ZooKeeper.getClientCnxnSocket(
        at org.apache.zookeeper.ZooKeeper.<init>(
        at org.apache.zookeeper.ZooKeeper.<init>(
        at org.apache.zookeeper.ZooKeeper.<init>(
        at org.apache.zookeeper.ZooKeeper.<init>(
        at io.confluent.admin.utils.ClusterStatus.isZookeeperReady(
        at io.confluent.admin.utils.cli.ZookeeperReadyCommand.main(
Caused by: java.lang.ClassNotFoundException:
        at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(
        at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(
        at java.base/java.lang.ClassLoader.loadClass(
        ... 9 more

After some additional investigation I found out, that the last working version for me is 6.1.3.
In 6.1.4 there was a Netty libs upgrade: Confluent Platform Component Changelogs | Confluent Documentation

I’m getting mentioned error because of following config in my docker-compose.yml:

Kafka environment variable:

KAFKA_OPTS: -Dzookeeper.clientCnxnSocket=org.apache.zookeeper.ClientCnxnSocketNetty

Zookeeper environment variable:

ZOOKEEPER_SERVER_CNXN_FACTORY: org.apache.zookeeper.server.NettyServerCnxnFactory

I was trying to find any required configuration change in documentation, but I still can see it as valid I guess: ZooKeeper Security | Confluent Documentation

As it was working before, I don’t expect any typo in my config. I’m using same images version for Kafka and Zookeeper.

Anyone had similar problem already? Any ideas how to solve that?

Best regards,