Replaces backend servers in a specified VServer group.

You can call this operation to replace the backend servers in the specified VServer group. If you want to modify the configuration of the backend servers, such as their weights, see SetVServerGroupAttribute.

Debugging

OpenAPI Explorer automatically calculates the signature value. For your convenience, we recommend that you call this operation in OpenAPI Explorer. OpenAPI Explorer dynamically generates the sample code of the operation for different SDKs.

Request parameters

Parameter Type Required Example Description
Action String Yes ModifyVServerGroupBackendServers

The operation that you want to perform.

Set the value to ModifyVServerGroupBackendServers.

RegionId String Yes cn-hangzhou

The ID of the region where the SLB instance is created.
VServerGroupId String Yes rsp-cige6j******

The ID of the VServer group.
OldBackendServers String No [{ "ServerId": "i-xxxxxxxxx", "Weight": "100", "Type": "ecs", "Port":"80","Description":"test-112" }]

The list of backend servers to be replaced.

The value of this parameter is a JSON string with a JSON List structure. You can specify up to 20 elements in a list in a request.

  • ServerId: the instance ID of the backend server. This parameter is required and must be set to a string.
  • Port: the port that is used by the backend server. This parameter is required and must be set to an integer. Valid values: 1 to 65535.
  • Weight: the weight of the backend server. This parameter is required and must be set to an integer. Valid values: 0 to 100.
  • Description: the description of the backend server. This parameter is optional. The description must be a string. The description must be 1 to 80 characters in length and can contain letters, digits, hyphens (-), forward slashes (/), periods (.), and underscores (_).
  • Type: the instance type of the backend server. This parameter must be set to a string. Valid values:
    • ecs: Elastic Compute Service (ECS) instance. This is the default value.
    • eni: elastic network interface (ENI).
  • ServerIp: the IP address of an ECS instance or ENI.

Examples:

  • ECS instance: [{ "ServerId": "i-xxxxxxxxx", "Weight": "100", "Type": "ecs", "Port": "80", "Description": "test-112" }].
  • ENI: [{ "ServerId": "eni-xxxxxxxxx", "Weight": "100", "Type": "eni", "ServerIp": "192.168. **. **", "Port":"80","Description":"test-112" }]
  • ENI with multiple IP addresses: [{ "ServerId": "eni-xxxxxxxxx", "Weight": "100", "Type": "eni", "ServerIp": "192.168. **. **", "Port":"80","Description":"test-112" },{ "ServerId": "eni-xxxxxxxxx", "Weight": "100", "Type": "eni", "ServerIp": "172.166. **. **", "Port":"80","Description":"test-113" }]
NewBackendServers String No [{ "ServerId": "eni-xxxxxxxxx", "Weight": "100", "Type": "eni", "ServerIp": "192.168. **. **", "Port":"80","Description":"test-112" },{ "ServerId": "eni-xxxxxxxxx", "Weight": "100", "Type": "eni", "ServerIp": "172.166. **. **", "Port":"80","Description":"test-113" }]

The list of new backend servers.

You can specify a maximum of 20 backend servers for each VServer group in each call.

The value of this parameter is a JSON string with a JSON List structure. You can specify up to 20 elements in a list in a request.

  • ServerId: the instance ID of the backend server. This parameter is required and must be set to a string.
  • Port: the port that is used by the backend server. This parameter is required and must be set to an integer. Valid values: 1 to 65535.
  • Weight: the weight of the backend server. This parameter is required and must be set to an integer. Valid values: 0 to 100.
  • Description: the description of the backend server. This parameter is optional. The description must be a string and can contain letters, digits, hyphens (-), forward slashes (/), periods (.), and underscores (_).
  • Type: the instance type of the backend server. This parameter must be set to a string. Valid values:
    • ecs: ECS instance. This is the default value.
    • eni: ENI.
  • ServerIp: the IP address of an ECS instance or ENI.

Examples:

  • ECS instance: [{ "ServerId": "i-xxxxxxxxx", "Weight": "100", "Type": "ecs", "Port": "80", "Description": "test-112" }].
  • ENI: [{ "ServerId": "eni-xxxxxxxxx", "Weight": "100", "Type": "eni", "ServerIp": "192.168. **. **", "Port":"80","Description":"test-112" }]
  • ENI with multiple IP addresses: [{ "ServerId": "eni-xxxxxxxxx", "Weight": "100", "Type": "eni", "ServerIp": "192.168. **. **", "Port":"80","Description":"test-112" },{ "ServerId": "eni-xxxxxxxxx", "Weight": "100", "Type": "eni", "ServerIp": "172.166. **. **", "Port":"80","Description":"test-113" }]

Response parameters

Parameter Type Example Description
VServerGroupId String rsp-cige6j******

The ID of the VServer group.
BackendServers Array

The list of backend servers.
BackendServer
ServerId String vm-236

The ID of the ECS instance or ENI.
Port Integer 70

The port that is used by the backend server.
Weight Integer 100

The weight of the backend server.
Description String The description of the backend server.

The description of the backend server.
Type String ecs

Type: the type of the backend server. Valid values:

  • ecs: ECS instance. This is the default value.
  • eni: ENI.
RequestId String 9DEC9C28-AB05-4DDF-9A78-6B08EC9CE18C

The ID of the request.

Examples

Sample requests

http(s)://[Endpoint]/? Action=ModifyVServerGroupBackendServers
&RegionId=cn-hangzhou
&VServerGroupId=rsp-cige6j******
&<Common request parameters>

Sample success responses

XML format 

<ModifyVServerGroupBackendServersResponse>
      <RequestId>9DEC9C28-AB05-4DDF-9A78-6B08EC9CE18C</RequestId>
	  <VServerGroupId>rsp-cige6j*****</VServerGroupId>
	  <BackendServers>
		    <BackendServer>
			      <ServerId>vm-400</ServerId>
			      <Port>80</Port>
			      <Weight>100</Weight>
		    </BackendServer>
		    <BackendServer>
			      <ServerId>vm-401</ServerId>
			      <Port>90</Port>
			      <Weight>100</Weight>
		    </BackendServer>
	  </BackendServers>
</ModifyVServerGroupBackendServersResponse>

JSON format 

{
  "ModifyVServerGroupBackendServersResponse": {
    "RequestId": "9DEC9C28-AB05-4DDF-9A78-6B08EC9CE18C",
    "VServerGroupId": "rsp-cige6j*****",
    "BackendServers": {
      "BackendServer": [
        {
          "ServerId": "vm-400",
          "Port": "80",
          "Weight": "100"
        },
        {
          "ServerId": "vm-401",
          "Port": "90",
          "Weight": "100"
        }
      ]
    }
  }
}

Error codes

For a list of error codes, visit the API Error Center.