Centralized cluster configuration will propagate server-side property values to use as default property values on clients. But our netty code relies on client-side default configuration to decide whether to use EPOLL or NIO by default. If the client doesn't configure the channel type to EPOLL or NIO, it will use whatever the server uses. This could cause an issue if the server supports EPOLL but EPOLL isn't available to the client. The client should never use EPOLL if it isn't available.