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    Server Load Balancer:Create and manage a vServer group

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    Server Load Balancer:Create and manage a vServer group

    Last Updated:Mar 12, 2025

    This topic describes how to create a vServer group for a Classic Load Balancer (CLB) instance. You can create vServer groups for CLB to distribute different requests to different backend servers. To allow CLB to distribute requests based on domain names or URLs, you can specify vServer groups in domain name-based forwarding rules or URL-based forwarding rules.

    Background information

    Before you create a vServer group, take note of the following items:

    • The Elastic Compute Service (ECS) instances that you add to a vServer group must be deployed in the same region as the CLB instance.

    • An ECS instance can be added to one or more vServer groups.

    • A vServer group can be associated with one or more listeners of a CLB instance.

    • When you add an ECS instance in a virtual private cloud (VPC) to an Internet-facing CLB instance, make sure that the VPC and the CLB instance are in the same region. When you add multiple ECS instances to an Internet-facing CLB instance, make sure that the ECS instances are in same VPC.

    Prerequisites

    Make sure that the ECS instances and the CLB instance are in the same region.

    Create a vServer group

    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. Click the ID of the CLB instance that you want to manage.

    4. Click the vServer groups tab and click Create vServer Group.

    5. On the Create vServer Group page, configure the following parameters:

      1. In the vServer Group Name field, enter a name for the vServer group.

      2. Enter a tag key in the Tag Key field and a tag value in the Tag Value field.

      3. In the Selected Servers section, click Add.

    6. In the Servers panel, select an ECS instance and click Next.

      • Select ECS instances

        Select ECS/ENI and select the ECS instances that you want to add.

      • Select elastic network interfaces (ENIs)

        1. Select ECS/ENI and turn on Advanced Mode.

        2. Click the Add icon to the right of the ECS instance ID and select the ENI that you want to add.

          Ensure that the ENI has been associated with the ECS instance.

      • Select Elastic Container Instances

        Select ECI and select the Elastic Container Instances that you want to add.

        You can click Purchase Elastic Container Instance in the upper-right corner of the list and buy a new instance.

    7. In the Ports/Weights step, specify a port and a weight for each server, and then click Add.

      • Port: Specify the backend port that the ECS instance uses to receive requests.

        ECS instances added to a CLB instance can use the same port.

      • Weight: A server that has a higher weight receives more requests.

        Important

        Valid values: 0 to 100. If the weight of a backend server is set to 0, no requests are sent to the backend server.

    8. Confirm the configurations and click Create. In the message that appears, click OK.

      Note

      Click Add More below Selected Servers to add additional ECS instances.

    Modify a vServer group

    After you create a vServer group, you can modify the configurations of ECS instances in the vServer group.

    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. Click the ID of the CLB instance that you want to manage.

    4. Click the vServer groups tab.

    5. Find the vServer group that you want to manage and click Modify in the Actions column.

    6. On the Modify vServer Group page, modify the information about the vServer group and click Save.

      • You can rename the vServer group.

      • You can modify the ports and weights of the ECS instances in the vServer group.

      • You can click Delete to remove an ECS instance from the vServer group.

        Note

        If the ECS instance is associated with a listener or a forwarding rule, disassociate the listener or forwarding rule from the ECS instance before you remove the ECS instance.

      • Click Add More. In the Servers panel, you can add additional ECS instances to the vServer group.

    Delete a vServer group

    If you no longer use a vServer group to receive requests, you can delete the vServer group.

    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. Click the ID of the CLB instance that you want to manage.

    4. Click the vServer groups tab.

    5. Find the vServer group that you want to delete and click Delete in the Actions column.

      Note

      If the vServer group is associated with a listener or a forwarding rule, disassociate the listener or forwarding rule from the vServer group before you delete the vServer group.

    6. In the message that appears, click OK.

    References