Register targets with your target group
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 your 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.
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.
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 or deregister targets
Each target group must have at least one registered target in each Availability Zone that is enabled for the Gateway Load Balancer.
The target type of your target group determines how you register targets with that target group. For more information, see Target type.
Requirements
-
You cannot register instances by instance ID if they are in a VPC that is peering to the load balancer VPC (same Region or different Region). You can register these instances by IP address.
Contents
Register or deregister targets by instance ID
An instance must be in the running
state when you register
it.
Register or deregister targets by IP address
An IP address that you register must be from one of the following CIDR blocks:
-
The subnets of the VPC for the target group
-
10.0.0.0/8 (RFC 1918)
-
100.64.0.0/10 (RFC 6598)
-
172.16.0.0/12 (RFC 1918)
-
192.168.0.0/16 (RFC 1918)
Register or deregister targets using the Amazon CLI
Use the register-targets command to add targets and the deregister-targets command to remove targets.