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Server Load Balancer:ModifyVServerGroupBackendServers

Last Updated:Mar 01, 2024

Replaces the backend servers in a server group.

Operation description

You can call this operation to replace the backend servers in a specified vServer group. To modify the configurations of the backend servers, such as their weights, you can call the SetVServerGroupAttribute operation.

Debugging

OpenAPI Explorer automatically calculates the signature value. For your convenience, we recommend that you call this operation in OpenAPI Explorer.

Authorization information

The following table shows the authorization information corresponding to the API. The authorization information can be used in the Action policy element to grant a RAM user or RAM role the permissions to call this API operation. Description:

  • Operation: the value that you can use in the Action element to specify the operation on a resource.
  • Access level: the access level of each operation. The levels are read, write, and list.
  • Resource type: the type of the resource on which you can authorize the RAM user or the RAM role to perform the operation. Take note of the following items:
    • The required resource types are displayed in bold characters.
    • If the permissions cannot be granted at the resource level, All Resources is used in the Resource type column of the operation.
  • Condition Key: the condition key that is defined by the cloud service.
  • Associated operation: other operations that the RAM user or the RAM role must have permissions to perform to complete the operation. To complete the operation, the RAM user or the RAM role must have the permissions to perform the associated operations.
OperationAccess levelResource typeCondition keyAssociated operation
slb:ModifyVServerGroupBackendServersWRITE
  • instance
    acs:ecs:{#regionId}:{#accountId}:instance/{#instanceId}
  • loadbalancer
    acs:slb:{#regionId}:{#accountId}:loadbalancer/{#loadbalancerId}
  • slb:tag
none

Request parameters

ParameterTypeRequiredDescriptionExample
RegionIdstringYes

The ID of the region where the Classic Load Balancer (CLB) instance is deployed.

cn-hangzhou
VServerGroupIdstringYes

The ID of the vServer group.

rsp-cige6j****
OldBackendServersstringNo

The list of backend servers that you want to replace in the vServer group. You can specify at most 20 backend servers for a vServer group in each call.

  • ServerId: required. The ID of the Elastic Compute Service (ECS) instance or elastic network interface (ENI) that serves as a backend server. This parameter must be of the STRING type.

  • Port: required. The port that is used by the backend server. This parameter must be of the INTEGER type. Valid values: 1 to 65535.

  • Weight: required. The weight of the backend server. This parameter must be of the INTEGER type. Valid values: 0 to 100.

  • Description: optional. The description of the backend server. This parameter must be of the STRING type. The description must be 1 to 80 characters in length, and can contain letters, digits, hyphens (-), forward slashes (/), periods (.),and underscores (_).

  • Type: the type of backend server. This parameter must be of the STRING type. Valid values:

    • ecs: an ECS instance. This is the default value.
    • eni: an ENI.
  • ServerIp: the IP address of the ECS instance or ENI.

Examples:

  • An ECS instance: [{ "ServerId": "i-xxxxxxxxx", "Weight": "100", "Type": "ecs", "Port":"80","Description":"test-112" }]
  • An ENI: [{ "ServerId": "eni-xxxxxxxxx", "Weight": "100", "Type": "eni", "ServerIp": "192.168.**.**", "Port":"80","Description":"test-112" }]
  • An 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" }]
[{ "ServerId": "i-xxxxxxxxx", "Weight": "100", "Type": "ecs", "Port":"80","Description":"test-112" }]
NewBackendServersstringNo

The list of new backend servers that you want to use to replace those in the vServer group. You can specify at most 20 backend servers for a vServer group in each call.

  • ServerId: required. The ID of the ECS instance or ENI that serves as a backend server. This parameter must be of the STRING type.

  • Port: required. The port that is used by the backend server. This parameter must be of the INTEGER type. Valid values: 1 to 65535.

  • Weight: required. The weight of the backend server. This parameter must be of the INTEGER type. Valid values: 0 to 100.

  • Description: optional. The description of the backend server. This parameter must be of the STRING type. The description can contain letters, digits, hyphens (-), forward slashes (/), periods (.),and underscores (_).

  • Type: the type of backend server. This parameter must be of the STRING type. Valid values:

    • ecs: an ECS instance. This is the default value.
    • eni: an ENI.
  • ServerIp: the IP address of the ECS instance or ENI.

Examples:

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

ParameterTypeDescriptionExample
object
VServerGroupIdstring

The ID of the vServer group.

rsp-cige6j****
RequestIdstring

The ID of the request.

9DEC9C28-AB05-4DDF-9A78-6B08EC9CE18C
BackendServersobject []

The list of backend servers.

Typestring

The type of backend server. Valid values:

  • ecs: an ECS instance. This is the default value.
  • eni: an ENI.
ecs
Weightinteger

The weight of the backend server.

100
Descriptionstring

The description of the backend server.

Backend server description
Portinteger

The port that is used by the backend server.

70
ServerIdstring

The ID of the ECS instance or ENI.

i-bp1ge5hrp****

Examples

Sample success responses

JSONformat

{
  "VServerGroupId": "rsp-cige6j****",
  "RequestId": "9DEC9C28-AB05-4DDF-9A78-6B08EC9CE18C",
  "BackendServers": {
    "BackendServer": [
      {
        "Type": "ecs",
        "Weight": 100,
        "Description": "Backend server description",
        "Port": 70,
        "ServerId": "i-bp1ge5hrp****"
      }
    ]
  }
}

Error codes

HTTP status codeError codeError messageDescription
400InvalidParameterThe specified BackendServers contain duplicated value of ServerId and Port.The specified backend servers contain duplicate service IDs and ports.
400Mismatched.ZoneIdThe zone of the server is not matched with the cloud box loadbalancer.-
400InvalidBackendServers.ServerIpConflict%s.-
400OperationUnsupported.ModifyVServerGroupBackendServersThis type of backend server is not allowed to attached to singleTunnel or anyTunnel lb.-
400IncorrectStatus.RSByPassToas%s.-
400BackendServer.InvalidTypeThe specified Type is invalid.-
400BackendServer.ServerRegionIdNotEqualThe specified ServerRegionId must be equal.-
400OperationFailed.InvalidCenThe cen related with this loadbalancer is invalid.-
400IncorrectStatus.CenNotAssociatedThe action is invalid because the loadbalancer is not associated with cen.-
400InvalidBackendServers.MissingCenBandWidthThe bandwidth is missing between loadbalancer and backendServers in cen.-
400InvalidBackendServers.VpcNotInCenThe BackendServers is not in the cen associated with the loadbalancer.-
400InvalidServerId.NotExistThe specified ServerId is not exist.-
400MissingParameter.ServerRegionIdThe parameter ServerRegionId is required.-
400MissingParameter.VbrIdThe parameter VbrId is required.-
400InvalidParameter.ServerRegionIdThe parameter ServerRegionId is invalid for crossborder.-
400InvalidVbrId.NotInCenThe VbrId is not in the cen associated with the loadbalancer.-
400InvalidParameter.ServerRegionIdThe specified ServerRegionId is invalid.-
400InvalidParameter.ZoneNotSupportThe zone does not support the parameter %s.-
400MasterSlaveServerConflictThe servers are conflict for MasterSlaveGroup.-
400NetworkConflict%s.-

For a list of error codes, visit the Service error codes.

Change history

Change timeSummary of changesOperation
2023-09-08The Error code has changedsee changesets
Change itemChange content
Error CodesThe Error code has changed.
    Error Codes 400 change