Remove stale database connections from the pool
This is a request to port fix from JA-5514.
+Description from the ticket: +
Connections were validated every minute and even if a connection was closed it could be still passed to a thread if a thread requested connection between subsequent validations.
With my change connections are proxied so that whenever a connection exception appears then a connection is marked as invalid immediately. So once it failed it won't be passed to any thread every after. As for the validation, it is still done every minute.
Unity is using datasource implementation from MyBatis -> PooledDataSource, which is nothing in common with jirav implementation.