Aurora MySQL Database cluster is in a state that cannot be upgraded: Engine bootstrap failed with no mysqld process running

Question

Hi,
I tried to upgrade mysql_aurora.2.11.1 (5.7) to mysql_aurora 3.02.2 (8.0.23). The RDS size is r5.2xlarge. 
It has done the online & offline pre-upgrade check. Then, cloning volume and upgrade process.  
However, it was rollback and display the error below in the logs & events at AWS console.  
"Database cluster is in a state that cannot be upgraded: Engine bootstrap failed with no mysqld process running..."

I have tried to use r5.4xlarge and upgrade from minor version then to mysql 8.0.23 but still failed. There was no issue to upgrade for my other mysql cluster & DB. Only this cluster having error. Please advise. Thanks.

Regards,
Barry

Accepted Answer

I have created a technical case for AWS Support to investigate the issue. 
It was due to table schema comments that contain invalid UTF-8 characters. After I remove the comment then Aurora can do the upgrade smoothly.

Answer

Check the Aurora MySQL error log.  
You can check "mysql-error.log" from the management console.  
https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/USER_LogAccess.MySQL.LogFileSize.html

I have found someone who is experiencing problems with a situation similar to yours.  
https://www.reddit.com/r/aws/comments/11i2dr4/unable_to_do_inline_upgrade_to_aurora_mysql_80_on/

Aurora MySQL Database cluster is in a state that cannot be upgraded: Engine bootstrap failed with no mysqld process running

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