@matthewb When i generate IAM token and use that password with below command, it fails with access denied error.
Command used:
pt-online-schema-change D=XXXX,t=XXXX,u=XXXX,h=XXXX.rds.amazonaws.com --ask-pass --critical-load Threads_running=1500 --alter-foreign-keys-method auto --recursion-method none --progress percentage,1 --no-check-alter --nodrop-old-table --execute --alter "ADD INDEX “XXXXX;”
Used the same token to login into the RDS via MySQL client through IAM authentication and it was successful. And i was able to use pt-online-schema-change as normal user. Issue[access denied] only comes when i use pt-online-schema-change with IAM token.