A virtual server group (VServer group) is a group of ECS instances. VServer groups allow you to manage and customize backend servers in the listener dimension. It allows listeners in a Server Load Balancer instance to use different backend servers. Then, different requests can be distributed to different backend servers.

Prerequisite

Background information

If you use a VServer group when configuring a listener, the listener distributes requests to the associated VServer group. The listener no longer distribute the requests to ECS instances in the backend server pool.

For a Layer-7 listener, if you add backend servers in the server pool, configure a VServer group, and adding a forwarding rule at the same time, the requests are distributed in the following order:

  • If the client requests match the configured domain name forwarding rule, the requests are distributed to the VServer group associated with the rule.
  • If not, the requests are distributed to the VServer group associated with the listener.
  • If no VServer group is configured for the listener, the requests are distributed to the ECS instances in the backend server pool.

When using the VServer group, note the following limitations:

  • Only backend servers in the same region as listeners can be added to a VServer group.
  • One ECS instance can be added to multiple VServer groups.
  • One VServer group can be associated with multiple listeners.
  • The VServer group consists of multiple ECS instances with different port numbers.

Procedure

  1. Log on to the SLB console.
  2. On the Instances page, select a region.
  3. Click the ID of an SLB instance.
  4. In the left-side navigation pane, click Server > VServer Group.
  5. On the VServer Group page, click Create VServer Groups.
  6. In the Create VServer Group dialog box, complete these steps:
    1. Enter a group name in the Group Name field.
    2. Select the network type for the ECS instance you want to add.
  7. In the Available Servers, select the ECS instances to add.
    The selected instances are displayed in the Selected Servers list.
  8. In the Selected Servers list, enter the port number and weight for each added ECS instance, and then click Confirm.
    The created VServer group is displayed on the VServer Group page. You can delete or add ECS instances for the VServer group (click Edit). You can also associate this VServer Group with the instance's listeners or forwarding rules.