This topic describes how to create an active/standby server group. If you need active/standby failover configurations, where one backend server is used as the active server and the other as the standby server, you can create an active/standby server group. When the active server works normally, requests are distributed to the active server. If the active server fails, requests are distributed to the standby server.


Before you create an active/standby server group, make sure the following conditions are met:
  • A Server Load Balancer (SLB) instance is created. For more information, see Create an SLB instance.
  • ECS instances are created and applications are deployed on the ECS instances to process distributed requests.


  1. Log on to the Server Load Balancer console.
  2. On the Server Load Balancer page, select the region of the target SLB instance.
  3. Find the target SLB instance and click the instance ID.
  4. Click the Active/Standby Server Groups tab.
  5. On the Active/Standby Server Groups tab, click Create Active/Standby Server Group.
  6. On the Create Active/Standby Server Group page, configure the active/standby server group.
    1. In the Name filed, enter a name for the active/standby server group to be created.
    2. Click Add and on the Available Servers page, select the servers you want to add to the active/standby server group.
      You can add only two ECS instances to an active/standby server group.
    3. Click Next: Set Weight and Port.
    4. In the Servers Added section, set the port, select an active server, and click OK.
      • Port: Set the backend port opened on the ECS instance to receive requests.

        The backend ports in an SLB instance can be the same.

      • Server: Select a server to act as the active server.