Register targets for your Gateway Load Balancer

When your target is ready to handle requests, you register it with one or more target groups. You can register targets by instance ID or by IP address. The Gateway Load Balancer starts routing requests to the target as soon as the registration process completes and the target passes the initial health checks. It can take a few minutes for the registration process to complete and health checks to start. For more information, see Health checks for Gateway Load Balancer target groups.

If demand on your currently registered targets increases, you can register additional targets in order to handle the demand. If demand on your registered targets decreases, you can deregister targets from your target group. It can take a few minutes for the deregistration process to complete and for the Gateway Load Balancer to stop routing requests to the target. If demand increases subsequently, you can register targets that you deregistered with the target group again. If you need to service a target, you can deregister it and then register it again when servicing is complete.

Considerations

Target security groups

When you register EC2 instances as targets, you must ensure that the security groups for these instances allow inbound and outbound traffic on port 6081.

Gateway Load Balancers do not have associated security groups. Therefore, the security groups for your targets must use IP addresses to allow traffic from the load balancer.

Network ACLs

When you register EC2 instances as targets, you must ensure that the network access control lists (ACL) for the subnets for your instances allow traffic on port 6081. The default network ACL for a VPC allows all inbound and outbound traffic. If you create custom network ACLs, verify that they allow the appropriate traffic.

Register targets by instance ID

An instance must be in the running state when you register it.

To register targets by instance ID using the AWS CLI

Use the register-targets command with the IDs of the instances.

Register targets by IP address

An IP address that you register must be from one of the following CIDR blocks:

To register targets by IP address using the AWS CLI

Use the register-targets command with the IP addresses of the targets.

Deregister targets

When you deregister a target, Elastic Load Balancing waits until in-flight requests have completed. This is known as connection draining. The status of a target is draining while connection draining is in progress. After deregistration is complete, status of the target changes to unused. For more information, see Deregistration delay.

To deregister targets using the AWS CLI

Use the deregister-targets command to remove targets.