Each Classic Load Balancer (CLB) instance is associated with a default server group. You can add Elastic Compute Service (ECS) to the default server group. All listeners on the CLB instance are associated with the default server group. This topic describes how to add an ECS instance to the default server group and manage the ECS instances in the default server group.

Prerequisites

Before you add an ECS instance to the default server group, make sure that the following requirements are met:
  • A CLB instance is created. For more information, see Create and manage a CLB instance.
  • ECS instances are created and applications are deployed on the ECS instances to receive requests.
    Note Make sure that the ECS instance and the CLB instance are in the same region.

Add an ECS instance to the default server group

  1. Log on to the CLB console.
  2. In the top navigation bar, select the region where the CLB instance is deployed.
  3. On the Instances page, find the CLB instance that you want to manage and click its ID.
  4. Click the Default Server Group tab and then click Add.
  5. In the Servers panel, select the ECS instance that you want to add and click Next.
  6. On the Ports/Weights page, specify a weight for the ECS instance and click Add.
    An ECS instance with a higher weight receives more requests. You can click Batch operation to specify the ports and weights of the added ECS instances in batches.
    • If you click Replicate to Below, the weights of all backend servers below the current server are set to the weight of the current server.
    • If you click Replicate to Above, the weights of all backend servers above the current server are set to the weight of the current server.
    • If you click Replicate to All, the weights of all backend servers in the default server group are set to the weight of the current server.
    • If you click Reset on the right side of Weight, the weights of all ECS instances in the sever group are set to the default value.
    Notice If you set the weight of an ECS instance to 0, the ECS instance does not receive requests.
  7. In the Available Servers panel, conform the configurations and click OK. In the message that appears, click OK.
    You can click Add More in the Available Servers panel to add more ECS instances.

Manage the ECS instances in the default server group

After you add ECS instances to the default server group, you can modify the weights of the ECS instances. If you no longer use an ECS instance, you can remove the ECS instance from the default server group.

  1. Log on to the CLB console.
  2. In the top navigation bar, select the region where the CLB instance is deployed.
  3. On the Instances page, find the CLB instance that you want to manage and click its ID.
  4. Click the Default Server Group tab. On this tab, you can manage the ECS instances.
    • Modify the weights of the ECS instances:
      1. Find the backend server that you want to manage, move the pointer over the weight specified for the backend sever, and then click the Edit icon icon.
      2. In the dialog box that appears, enter a weight for the ECS instance and click OK.
        Notice If you set the weight of an ECS instance to 0, the ECS instance does not receive requests.
    • Remove an ECS instance:
      1. Find the ECS instance that you want to remove and click Remove in the Operations column.
      2. In the Confirm message, click Remove.

References