Application Load Balancer enables configuring HTTP client keepalive duration

Application Load Balancer (ALB) now 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. You can now set a value between 60 seconds and 7 days using a load balancer attribute as your clients’ keepalive duration, while the default value is 3600 seconds.

You can configure the client connection duration via the AWS Management Console, API, or Command Line Interface (CLI).

There is no additional charge for using these features. The HTTP client keep-alive duration is now available in all commercial AWS Regions.

^{5/16/2024 - This post has been updated to clarify that this feature is only available in commerical regions and not in GovCloud.}