Problem with Blue/Green Deployment: Invalid Configuration error

Hello,

As the DB engine version upgrade failed, Blue-green deployment is in "invalid_configuration state". Most common cause of upgrade failure is the failure of Prechecks for patching, (do check the recent events of green instance to see the cause of upgrade failure), If it is due to failure of pre-checks then in the logs of green instance and go through the "PrePatchCompatibility.log" file.

[+]https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_UpgradeDBInstance.MySQL.html#USER_UpgradeDBInstance.MySQL.57to80Prechecks

[+]https://repost.aws/knowledge-center/rds-mysql-preupgrade-failure

You have to delete the current Blue/green deployment, Resolve the errors reported in the log file and then deploy a new blue/green deployment.

This was mainly due to custom option group associated with my source DB instance. Apparently, you can not be able to pick a major version upgrade for the Green instance when the Blue instance has a custom parameter group. You would rather have to set a minor version for the green instance and after the deployment is complete, you upgrade the green instance to a major version and then you can switchover to the green instance if all test cases pass

https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/blue-green-deployments-overview.html#blue-green-deployments-limitations-changes