Exception in logs after datastax-enterprise cassandra Upgrade

Question

I have recently upgraded datastax-enterprise from 4.8.16 to 5.0.15. After the upgrade I see below exception in logs, although the Cassandra queries are running fine.

INFO   [epollEventLoopGroup-6-10 - org.apache.cassandra.transport.Message:627] Unexpected exception during request; channel = [id: 0x9b377ba1, L:/10.26.156.233:9042 ! R:/10.26.143.14:43788]
java.nio.channels.ClosedChannelException: null
    at io.netty.channel.AbstractChannel$AbstractUnsafe.close(...)(Unknown Source)
2018-12-11 09:35:42.478 INFO   [epollEventLoopGroup-6-10 - org.apache.cassandra.transport.Message:627] Unexpected exception during request; channel = [id: 0x9b377ba1, L:/10.26.156.233:9042 ! R:/10.26.143.14:43788]
java.nio.channels.ClosedChannelException: null

Answer 1

I was able to resolve this. As DSE Cassandra 5.0 doesn't support Thrift protocol, and some of the application (dont ask me why, some very old applications) using Thrift protocol to connect with Upgraded cassandra causing this error.