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    Server Load Balancer:CreateServerGroup

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    Server Load Balancer:CreateServerGroup

    Last Updated:Mar 23, 2026

    Creates a server group for a Gateway Load Balancer (GWLB) instance.

    Operation description

    CreateServerGroup is an asynchronous operation. After a request is sent, the system returns a request ID and runs the task in the background. You can call the ListServerGroups operation to query the status of the task.

    • If the server group is in the Creating state, it indicates that the server group is being created.

    • If the server group is in the Available state, it indicates that the server group is created.

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    RAM authorization

    The table below describes the authorization required to call this API. You can define it in a Resource Access Management (RAM) policy. The table's columns are detailed below:

    • Action: The actions can be used in the Action element of RAM permission policy statements to grant permissions to perform the operation.

    • API: The API that you can call to perform the action.

    • Access level: The predefined level of access granted for each API. Valid values: create, list, get, update, and delete.

    • Resource type: The type of the resource that supports authorization to perform the action. It indicates if the action supports resource-level permission. The specified resource must be compatible with the action. Otherwise, the policy will be ineffective.

      • For APIs with resource-level permissions, required resource types are marked with an asterisk (*). Specify the corresponding Alibaba Cloud Resource Name (ARN) in the Resource element of the policy.

      • For APIs without resource-level permissions, it is shown as All Resources. Use an asterisk (*) in the Resource element of the policy.

    • Condition key: The condition keys defined by the service. The key allows for granular control, applying to either actions alone or actions associated with specific resources. In addition to service-specific condition keys, Alibaba Cloud provides a set of common condition keys applicable across all RAM-supported services.

    • Dependent action: The dependent actions required to run the action. To complete the action, the RAM user or the RAM role must have the permissions to perform all dependent actions.

    Action

    Access level

    Resource type

    Condition key

    Dependent action

    gwlb:CreateServerGroup

    create

    *ServerGroup

    acs:gwlb:{#regionId}:{#accountId}:servergroup/*

    *VPC

    acs:vpc:{#regionId}:{#accountId}:vpc/{#VpcId}

    None

    None

    Request parameters

    Parameter

    Type

    Required

    Description

    Example

    ServerGroupType

    string

    No

    The type of the server group. Valid values:

    • Instance (default): allows you to specify resources of the Ecs, Eni, or Eci type.

    • Ip: allows you to add servers by specifying their IP addresses.

    Instance

    ServerGroupName

    string

    No

    The server group name.

    The name must be 2 to 128 characters in length, and can contain digits, periods (.), underscores (_), and hyphens (-). It must start with a letter.

    testServerGroupName

    Protocol

    string

    No

    The backend protocol. Valid value:

    • GENEVE (default)

    Valid values:

    • GENEVE :

      GENEVE

    GENEVE

    Scheduler

    string

    No

    The scheduling algorithm. Valid values:

    • 5TCH (default): specifies consistent hashing that is based on the following factors: source IP address, destination IP address, source port, protocol, and destination port. Requests that contain the same information based on the preceding factors are forwarded to the same backend server.

    • 3TCH: specifies consistent hashing that is based on the following factors: source IP address, destination IP address, and protocol. Requests that contain the same information based on the preceding factors are forwarded to the same backend server.

    • 2TCH: specifies consistent hashing that is based on the following factors: source IP address and destination IP address. Requests that contain the same information based on the preceding factors are forwarded to the same backend server.

    5TCH

    ServerFailoverMode

    string

    No

    Specifies how GWLB processes requests over existing connections when a backend server is not running as expected. Valid values:

    • NoRebalance (default): GWLB continues to forward requests over existing connections to the unavailable backend server.

    • Rebalance: GWLB forwards requests over existing connections to the remaining healthy backend servers.

    NoRebalance

    VpcId

    string

    Yes

    The VPC ID.

    Note

    If ServerGroupType is set to Instance, only servers in the specified VPC can be added to the server group.

    vpc-bp15zckdt37pq72zv****

    ResourceGroupId

    string

    No

    The resource group ID.

    rg-atstuj3rtop****

    ConnectionDrainConfig

    object

    No

    The configurations of connection draining.

    ConnectionDrainEnabled

    boolean

    No

    Specifies whether to enable connection draining. Valid values:

    • true

    • false

    false

    ConnectionDrainTimeout

    integer

    No

    The timeout period of connection draining.

    Unit: seconds

    Valid values: 1 to 3600.

    Default value: 300.

    300

    HealthCheckConfig

    object

    No

    The health check configurations.

    HealthCheckConnectPort

    integer

    No

    The backend server port used for health checks.

    Valid values: 1 to 65535.

    Default value: 80.

    80

    HealthCheckConnectTimeout

    integer

    No

    The maximum timeout period for a health check response.

    Unit: seconds.

    Valid values: 1 to 300.

    Default value: 5.

    5

    HealthCheckDomain

    string

    No

    The domain name used for health checks. Valid values:

    • $SERVER_IP (default): the private IP address of a backend server.

    • domain: a domain name. The domain name must be 1 to 80 characters in length, and can contain letters, digits, hyphens (-), and periods (.).

    Note

    This parameter takes effect only if you set HealthCheckProtocol to HTTP.

    $SERVER_IP

    HealthCheckEnabled

    boolean

    No

    Specifies whether to enable health checks. Valid values:

    • true (default)

    • false

    true

    HealthCheckHttpCode

    array

    No

    The HTTP status codes that the system returns for health checks.

    string

    No

    The HTTP status codes returned for health checks. Multiple HTTP status codes are separated by commas (,). Valid values:

    • http_2xx

    • http_3xx

    • http_4xx

    • http_5xx

    Default value: http_2xx.

    Note

    This parameter takes effect only if you set HealthCheckProtocol to HTTP.

    http_2xx

    HealthCheckInterval

    integer

    No

    The interval at which health checks are performed.

    Unit: seconds.

    Valid values: 1 to 50.

    Default value: 10.

    10

    HealthCheckPath

    string

    No

    The path used for health checks.

    It must be 1 to 80 characters in length, and can contain letters, digits, hyphens (-), forward slashes (/), periods (.), percent signs (%), question marks (?), number signs (#), and ampersands (&). The URL can also contain the following extended characters: _ ; ~ ! ( ) * [ ] @ $ ^ : ' , + =

    It must start with a forward slash (/).

    Note

    This parameter takes effect only if you set HealthCheckProtocol to HTTP.

    /test/index.html

    HealthCheckProtocol

    string

    No

    The protocol used for health checks. Valid values:

    • TCP (default): GWLB performs TCP health checks by sending SYN packets to a backend server to check whether the port of the backend server is available to receive requests.

    • HTTP: GWLB performs HTTP health checks to check whether backend servers are healthy by sending GET requests which simulate access from browsers.

    TCP

    HealthyThreshold

    integer

    No

    The number of times that an unhealthy backend server must consecutively pass health checks before it is declared healthy. In this case, the health check status of the backend server changes from fail to success.

    Valid values: 2 to 10.

    Default value: 2.

    2

    UnhealthyThreshold

    integer

    No

    The number of times that a healthy backend server must consecutively fail health checks before it is declared unhealthy. In this case, the health check status of the backend server changes from success to fail.

    Valid values: 2 to 10.

    Default value: 2.

    2

    HealthCheckReq

    string

    No

    HealthCheckExp

    string

    No

    Tag

    array<object>

    No

    The tag keys.

    You can specify at most 20 tags in each call.

    object

    No

    The tag.

    Key

    string

    No

    The tag key. The tag key cannot be an empty string. The tag key can be up to 128 characters in length, and cannot start with acs: or aliyun. The tag key cannot contain http:// or https://.

    testTagKey

    Value

    string

    No

    The tag value. The tag value can be up to 256 characters in length and cannot contain http:// or https://.

    testTagValue

    DryRun

    boolean

    No

    Specifies whether to perform only a dry run without performing the actual request. Valid values:

    • true: performs only a dry run. The system checks the request for potential issues, including missing parameter values, incorrect request syntax, and service limits. If the request fails the dry run, an error code is returned. If the request passes the dry run, the DryRunOperation error code is returned.

    • false (default): performs a dry run and performs the actual request. If the request passes the dry run, a 2xx HTTP status code is returned and the operation is performed.

    False

    ClientToken

    string

    No

    The client token that is used to ensure the idempotence of the request.

    You can use the client to generate the token, but you must make sure that the token is unique among different requests. The client token can contain only ASCII characters.

    Note

    If you do not specify this parameter, the system automatically uses the request ID as the client token. The request ID may be different for each request.

    123e4567-e89b-12d3-a456-42665544****

    Response elements

    Element

    Type

    Description

    Example

    object

    RequestId

    string

    The request ID.

    54B48E3D-DF70-471B-AA93-08E683A1B45

    ServerGroupId

    string

    The server group ID.

    sgp-atstuj3rtoptyui****

    Examples

    Success response

    JSON format

    {
  "RequestId": "54B48E3D-DF70-471B-AA93-08E683A1B45",
  "ServerGroupId": "sgp-atstuj3rtoptyui****"
}

    Error codes

    HTTP status code

    Error code

    Error message

    Description

    400

    IllegalParam.HealthCheckProtocol

    The param of %s is illegal.

    The health check protocol is invalid. Check the input parameters.

    400

    QuotaExceeded.ServerGroupsNum

    The quota of %s is exceeded for resource %s, usage %s/%s.

    The quota gwlb_quota_servergroups_num has exceeded the quota limit.

    400

    DuplicatedParam.TagKey

    The param of %s is duplicated.

    The parameter of tag key is duplicated.

    400

    IllegalParam.TagKey

    The param of %s is illegal.

    404

    ResourceNotFound.Vpc

    The specified resource of %s is not found.

    The specified virtual private cloud resource does not exist.

    See Error Codes for a complete list.

    Release notes

    See Release Notes for a complete list.