Re: Flush Hosts Didn't Work

[Peter Brawley]

> from JDBC:
> 'Testing failed: invalid connection properties setting.
> 'null, message from server "Host '...' is blocked because of many connection errors

Sounds like an app not correctly tuned to a system, and possibly vice versa. I'd start with the code to which the app error log reports point, and with an analysis of MySQL's memory use (for which http://mysql.rjweb.org/doc.php/memory will be helpful).