In the past 1 week, I encountered an issue that I couldn’t add a column to a table in one of our production database. I thought restart would resolve the issue. After a restart, however the issue still persist. I checked logs in error/mysql-error-running.log in rds and noticed there are two transactions in prepared state after recovery. In the first gooogle search result page, How to Deal with XA Transactions Recovery caught my attention.

When I tried to create an user for application instead of giving out the master user and its password. I got "Error Code: 1045. Access denied for user 'mysqladmin'@'%' (using password: YES)" when I run "GRANT ALL PRIVILEGES ON demodb.* TO 'appadmin'@'%';". I tried the method in How do I create another master user for my Amazon RDS DB instance that is running MySQL?, it is for creating another master user with more permissions than an app db user.