MySQL Connector/J : Disable profileSQL and logSlowQueries properties in production.

Connector J will generate a lot of stacktrace outputs to standard error per query, regardless of whether the query is slow or not.

The main process flow of com.mysql.cj.protocol.a.NativeProtocol.sendQueryPacket()

 send query
 read result set
 if (this.profileSQL || this.logSlowQueries)  {
    fire QUERY ProfilerEvent
    logger.logInfo(event)
    get stack trace by create a Throwable object.
    System.err.println(messageAsString);//stack trace included in messageAsString
 }

References:
1. MySQL Connector/J Configuration Properties
2. Connector J with profileSQL – log contains lots of STACKTRACE data
3. Creating an exception in Java is very slow