max_auth_errors_until_block blocking complete hosts and causing outage

Maxscale variable max_auth_errors_until_block blocking complete hosts and causing application outage.

As the default value is 10, after 10 failure attempts, it blocks the complete host/IP rather than just the user with authentication failure issue. This blocking causing the application outage.

• This behaviour impacts the complete business, rather it should be blocking only the user which is failing authentication and not the whole application.
• Client point of view is that this is a bug in implementation, this behaviour affected the trading system where the whole application got blocked. The 60 seconds gap caused the outage in client environment, and it keeps repeating after 60 seconds if there are more failures.
• So, for example if there is a new feature rollout for one of the application and during the automation if there is some wrong password or authentication fails for any reason, the complete host is blocked which is running the load balancer and the same load balancer has multiple applications running using different databases in MariaDB and this cause outage in other non-related applications as well. Multiple applications trying to access and all gets blocked, if one user fails authentication.
• Client also wants to understand the reason for which this variable was introduced and how fast this can be fixed.