IAmazonElasticLoadBalancing

Each tag consists of a key and an optional value. If a tag with the same key is already associated with the load balancer, AddTags updates its value.

For more information, see Tag Your Load Balancer in the Elastic Load Balancing Developer Guide.

For more information, see Security Groups for Load Balancers in a VPC in the Elastic Load Balancing Developer Guide.

The load balancer evenly distributes requests across all registered subnets. For more information, see Add or Remove Subnets for Your Load Balancer in a VPC in the Elastic Load Balancing Developer Guide.

For more information, see Configure Health Checks in the Elastic Load Balancing Developer Guide.

This policy is similar to the policy created by CreateLBCookieStickinessPolicy, except that the lifetime of the special Elastic Load Balancing cookie, AWSELB, follows the lifetime of the application-generated cookie specified in the policy configuration. The load balancer only inserts a new stickiness cookie when the application response includes a new application cookie.

If the application cookie is explicitly removed or expires, the session stops being sticky until a new application cookie is issued.

For more information, see Application-Controlled Session Stickiness in the Elastic Load Balancing Developer Guide.

When a load balancer implements this policy, the load balancer uses a special cookie to track the back-end server instance for each request. When the load balancer receives a request, it first checks to see if this cookie is present in the request. If so, the load balancer sends the request to the application server specified in the cookie. If not, the load balancer sends the request to a server that is chosen based on the existing load-balancing algorithm.

A cookie is inserted into the response for binding subsequent requests from the same user to that server. The validity of the cookie is based on the cookie expiration time, which is specified in the policy configuration.

For more information, see Duration-Based Session Stickiness in the Elastic Load Balancing Developer Guide.

If the call completes successfully, a new load balancer is created with a unique Domain Name Service (DNS) name. The load balancer receives incoming traffic and routes it to the registered instances. For more information, see How Elastic Load Balancing Works in the Elastic Load Balancing Developer Guide.

You can create up to 20 load balancers per region per account. You can request an increase for the number of load balancers for your account. For more information, see Elastic Load Balancing Limits in the Elastic Load Balancing Developer Guide.

For more information, see Add a Listener to Your Load Balancer in the Elastic Load Balancing Developer Guide.

Policies are settings that are saved for your load balancer and that can be applied to the front-end listener or the back-end application server, depending on the policy type.

If you are attempting to recreate a load balancer, you must reconfigure all settings. The DNS name associated with a deleted load balancer are no longer usable. The name and associated DNS record of the deleted load balancer no longer exist and traffic sent to any of its IP addresses is no longer delivered to back-end instances.

If the load balancer does not exist or has already been deleted, the call to DeleteLoadBalancer still succeeds.

You can use DescribeLoadBalancers to verify that the instance is deregistered from the load balancer.

For more information, see Deregister and Register Amazon EC2 Instances in the Elastic Load Balancing Developer Guide.

If you specify a load balancer name, the action returns the descriptions of all policies created for the load balancer. If you specify a policy name associated with your load balancer, the action returns the description of that policy. If you don't specify a load balancer name, the action returns descriptions of the specified sample policies, or descriptions of all sample policies. The names of the sample policies have the ELBSample- prefix.

If you specify a load balancer name, the action returns the descriptions of all policies created for the load balancer. If you specify a policy name associated with your load balancer, the action returns the description of that policy. If you don't specify a load balancer name, the action returns descriptions of the specified sample policies, or descriptions of all sample policies. The names of the sample policies have the ELBSample- prefix.

You can use these policy types with CreateLoadBalancerPolicy to create policy configurations for a load balancer.

You can use these policy types with CreateLoadBalancerPolicy to create policy configurations for a load balancer.

After a subnet is removed, all EC2 instances registered with the load balancer in the removed subnet go into the OutOfService state. Then, the load balancer balances the traffic among the remaining routable subnets.

There must be at least one Availability Zone registered with a load balancer at all times. After an Availability Zone is removed, all instances registered with the load balancer that are in the removed Availability Zone go into the OutOfService state. Then, the load balancer attempts to equally balance the traffic among its remaining Availability Zones.

For more information, see Disable an Availability Zone from a Load-Balanced Application in the Elastic Load Balancing Developer Guide.

The load balancer evenly distributes requests across all its registered Availability Zones that contain instances.

For more information, see Add Availability Zone in the Elastic Load Balancing Developer Guide.

You can modify the load balancer attributes, such as AccessLogs, ConnectionDraining, and CrossZoneLoadBalancing by either enabling or disabling them. Or, you can modify the load balancer attribute ConnectionSettings by specifying an idle connection timeout value for your load balancer.

For more information, see the following in the Elastic Load Balancing Developer Guide:

• Cross-Zone Load Balancing
• Connection Draining
• Access Logs
• Idle Connection Timeout

The instance must be a running instance in the same network as the load balancer (EC2-Classic or the same VPC). If you have EC2-Classic instances and a load balancer in a VPC with ClassicLink enabled, you can link the EC2-Classic instances to that VPC and then register the linked EC2-Classic instances with the load balancer in the VPC.

Note that RegisterInstanceWithLoadBalancer completes when the request has been registered. Instance registration takes a little time to complete. To check the state of the registered instances, use DescribeLoadBalancers or DescribeInstanceHealth.

After the instance is registered, it starts receiving traffic and requests from the load balancer. Any instance that is not in one of the Availability Zones registered for the load balancer is moved to the OutOfService state. If an Availability Zone is added to the load balancer later, any instances registered with the load balancer move to the InService state.

If you stop an instance registered with a load balancer and then start it, the IP addresses associated with the instance changes. Elastic Load Balancing cannot recognize the new IP address, which prevents it from routing traffic to the instances. We recommend that you use the following sequence: stop the instance, deregister the instance, start the instance, and then register the instance. To deregister instances from a load balancer, use DeregisterInstancesFromLoadBalancer.

For more information, see Deregister and Register EC2 Instances in the Elastic Load Balancing Developer Guide.

For more information about updating your SSL certificate, see Updating an SSL Certificate for a Load Balancer in the Elastic Load Balancing Developer Guide.

Each time you use SetLoadBalancerPoliciesForBackendServer to enable the policies, use the PolicyNames parameter to list the policies that you want to enable.

You can use DescribeLoadBalancers or DescribeLoadBalancerPolicies to verify that the policy is associated with the back-end server.