I have a Percona mysql8.0.23 cluster, 1 master with 2 slaves on Ubuntu20, after I start io thread on slave, there are many unauthenticated user on the master, once I stop io thread, they are immediately gone, any ideas how can I troubleshoot? I set skip-name-resolve and there is no unknown ip access master, after I switch master to another machine, the problem still exists.
Switch off thread pool and the problem will go away
i.e. thread_handling = one-thread-per-connection