We are using AWS Aurora MySQL and we recently moved to MySQL 5.7. After moving to this version, we started seeing issues with DDL statements. The processes which are running these statements just hangs in state "Waiting for table metadata lock". When we tried to kill the process, the state change to "Killed" but the process is still running (We can see it when we run "show full processlist"). We waited for 24 hours and it never killed the process. We ended up restarting the DB. But we can't do that every time. Did someone face same problem with MySQL 5.7 and solved it somehow?