Now, Application Load Balancer (ALB) provides flexibility that allows you to configure HTTP client keepalive duration for communication between clients and load balancer. With this feature, you can configure keepalive values to optimize client experience.
The HTTP client keepalive duration value specifies the maximum amount of time that ALB will maintain an HTTP connection with a client before closing the connection.
The feature will allow customers to gracefully terminate their connections for deployment patterns like Blue/Green or rollbacks, migration of legacy applications, and while evacuating Availability Zones using zonal shift with Amazon Route 53 Application Recovery Controller.
It is possible to set a value between 60 seconds and 7 days using a load balancer attribute as app clients’ keepalive duration, while the default value is 3600 seconds.