This topic describes how to add a default backend server. Before you use the Classic Load Balancer (CLB) service, you must add at least one default backend server to receive client requests.

Prerequisites

Before you add an Elastic Compute Service (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 a CLB instance.
  • ECS instances are created and applications are deployed on the ECS instances to receive requests.

Procedure

  1. Log on to the CLB console.
  2. On the Instances page, select the region where the CLB instance that you want to manage is deployed.
  3. Find the CLB instance that you want to manage and click its ID.
  4. Click the Default Server Group tab.
  5. Click Add.
  6. In the My Servers panel, for Select Servers, select one or more ECS instances that you want to add to the default server group.
  7. Click Next.
  8. For Configure Ports and Weights, specify the weight of each ECS instance.
    An ECS instance that has a higher weight receives more requests.
    You can change the weight of a server and then move the pointer over Batch operations to change the weights of other servers:
    • If you click Replicate to Below, the weights of all servers below the current server are set to the weight of the current server.
    • If you click Replicate to Above, the weights of all servers above the current server are set to the weight of the current server.
    • If you click Replicate to All, the weights of all servers in the default server group are set to the weight of the current server.
    • If you click Reset, when you clear the weight of the current server, the weights of all servers in the default server group are cleared.
    Notice
    • Valid values of weights: 0 to 100. If you set the weight of a server to 0, the server does not receive requests.
    • If two servers have the same weight, only one server receives requests.
  9. Click Add.
  10. Click OK.