The Application Load Balancer reserves cookie names starting with the prefixes 'AWSALB', 'AWSALBAPP', and 'AWSALBTG' for its own use; custom application-based cookies cannot use these names [citation:3][citation:7].
When using sticky sessions on an Application Load Balancer (ALB), the load balancer uses specific cookie names for its own stickiness mechanisms [citation:3][citation:7]:
AWSALB: Used by the ALB for duration-based stickiness.AWSALBAPP: Used by the ALB for application-based cookies.AWSALBTG: Reserved for use by the ALB for target group stickiness.
These cookie names are reserved for exclusive use by the AWS load balancer. When implementing your own application-based cookies for stickiness, you must avoid using names that start with these prefixes, as they will be overwritten or ignored by the ALB [citation:7].