Creating an AS Group

Function

An AS group consists of a collection of instances that apply to the same scenario. It is the basis for enabling or disabling AS policies and performing scaling actions. An AS group specifies parameters, such as the maximum number of instances, expected number of instances, minimum number of instances, VPC, subnet, and load balancing.

  • Each user can create a maximum of 25 AS groups by default.

  • If ELB is configured, AS automatically binds or unbinds a load balancer to or from an instance when the instance is added to or removed from the AS group.

  • If an AS group uses ELB health check, the listening ports on the load balancers must be enabled for the instances in the AS group. Enable the listening ports in security groups.

URI

POST /autoscaling-api/v1/{project_id}/scaling_group

Table 1 Parameter description

Parameter

Mandatory

Type

Description

project_id

Yes

String

Specifies the project ID.

Request

Table 2 Request parameters

Parameter

Mandatory

Type

Description

scaling_group_name

Yes

String

Specifies the AS group name. The name contains only letters, digits, underscores (_), and hyphens (-), and cannot exceed 64 characters.

scaling_configuration_id

Yes

String

Specifies the AS configuration ID, which can be obtained using the API for querying AS configurations. For details, see Querying AS configurations.

desire_instance_number

No

Integer

Specifies the expected number of instances. The default value is the minimum number of instances.

The value ranges from the minimum number of instances to the maximum number of instances.

min_instance_number

No

Integer

Specifies the minimum number of instances. The default value is 0.

max_instance_number

No

Integer

Specifies the maximum number of instances. The default value is 0.

cool_down_time

No

Integer

Specifies the cooldown period (in seconds). The value ranges from 0 to 86400 and is 300 by default.

After a scaling action is triggered, the system starts the cooldown period. During the cooldown period, scaling actions triggered by alarms will be denied. Scheduled, periodic, and manual scaling actions are not affected.

lb_listener_id

No

String

Specifies the ELB listener ID. You can add up to six load balancer listeners. Separate listener IDs with commas (,).

lbaas_listeners

No

Array of lbaas_listeners objects

Specifies information about an ELB load balancer. You can add up to six load balancers. This parameter is in list data structure. For details, see Table 3.

available_zones

No

Array of strings

Specifies the AZ information. The instances added in a scaling action will be created in a specified AZ. If you do not specify an AZ, the system automatically specifies one.

networks

Yes

Array of networks objects

Specifies network information. You can select up to five subnets. The first subnet you select is used by the primary NICs of ECSs by default. For the information about the data structure, see Table 4.

security_groups

No

Array of security_groups objects

Specifies the security group. A maximum of one security group can be selected. For the information about the data structure, see Table 5.

If the security group is specified both in the AS configuration and AS group, scaled ECS instances will be added to the security group specified in the AS configuration. If the security group is not specified in either of them, scaled ECS instances will be added to the default security group. For your convenience, you are advised to specify the security group in the AS configuration.

vpc_id

Yes

String

Specifies the VPC ID, which can be obtained using the API for querying VPCs. For details, see "Querying VPCs" in Virtual Private Network API Reference.

health_periodic_audit_method

No

String

Specifies the health check method for instances in the AS group. The health check methods include ELB_AUDIT and NOVA_AUDIT. When load balancing is configured for an AS group, the default value is ELB_AUDIT. Otherwise, the default value is NOVA_AUDIT.

  • ELB_AUDIT: indicates the ELB health check, which takes effect in an AS group with a listener.

  • NOVA_AUDIT: indicates the ECS instance health check, which is the health check method delivered with AS.

health_periodic_audit_time

No

Integer

Specifies the instance health check period. The value can be 1, 5, 15, 60, or 180 in the unit of minutes. If this parameter is not specified, the default value is 5.

If the value is set to 0, health check is performed every 10 seconds.

health_periodic_audit_grace_period

No

Integer

Specifies the grace period for instance health check. The unit is second and the value ranges from 0 to 86400. The default value is 600.

The health check grace period starts after an instance is added to an AS group and is enabled. The AS group will start checking the instance status only after the grace period ends.

This parameter is valid only when the instance health check method of the AS group is ELB_AUDIT.

instance_terminate_policy

No

String

Specifies the instance removal policy.

  • OLD_CONFIG_OLD_INSTANCE (default): The earlier-created instances based on the earlier-created AS configurations are removed first.

  • OLD_CONFIG_NEW_INSTANCE: The later-created instances based on the earlier-created AS configurations are removed first.

  • OLD_INSTANCE: The earlier-created instances are removed first.

  • NEW_INSTANCE: The later-created instances are removed first.

notifications

No

Array of strings

Specifies the notification mode.

EMAIL refers to notification by email.

delete_publicip

No

Boolean

Specifies whether to delete the EIP bound to the ECS when deleting the ECS. The value can be true or false. The default value is false.

  • true: deletes the EIP bound to the ECS when deleting the ECS.

  • false: only unbinds the EIP bound to the ECS when deleting the ECS.

delete_volume

No

Boolean

Specifies whether to delete the data disks attached to the ECS when deleting the ECS. The value can be true or false. The default value is false.

  • true: deletes the data disks attached to the ECS when deleting the ECS.

  • false: only detaches the data disks attached to the ECS when deleting the ECS.

multi_az_priority_policy

No

String

Specifies the priority policy used to select target AZs when adjusting the number of instances in an AS group.

  • EQUILIBRIUM_DISTRIBUTE (default): When adjusting the number of instances, ensure that instances in each AZ in the available_zones list is evenly distributed. If instances cannot be added in the target AZ, select another AZ based on the PICK_FIRST policy.

  • PICK_FIRST: When adjusting the number of instances, target AZs are determined in the order in the available_zones list.

description

No

String

Specifies the description of the AS group. The value can contain 1 to 256 characters.

Table 3 lbaas_listeners field description

Parameter

Mandatory

Type

Description

pool_id

Yes

String

Specifies the backend ECS group ID.

protocol_port

Yes

Integer

Specifies the backend protocol ID, which is the port on which a backend ECS listens for traffic. The port ID ranges from 1 to 65535.

weight

Yes

Integer

Specifies the weight, which determines the portion of requests a backend ECS processes when being compared to other backend ECSs added to the same listener. The value of this parameter ranges from 0 to 100.

Table 4 networks field description

Parameter

Mandatory

Type

Description

id

Yes

String

Specifies the subnet ID.

Table 5 security_groups field description

Parameter

Mandatory

Type

Description

id

Yes

String

Specifies the security group ID.

Example Request

This example creates an AS group with the name GroupNameTest, the AS configuration ID 47683a91-93ee-462a-a7d7-484c006f4440, the VPC ID a8327883-6b07-4497-9c61-68d03ee193a, the NIC ID 3cd35bca-5a10-416f-8994-f79169559870, the maximum number of instances of 10, the expected number of instances of 0, the minimum number of instances of 0, and the health check method of ECS health check, and the multi-AZ scaling policy of PICK_FIRST.

{
    "scaling_group_name": "GroupNameTest",
    "scaling_configuration_id": "47683a91-93ee-462a-a7d7-484c006f4440",
    "desire_instance_number": 0,
    "min_instance_number": 0,
    "max_instance_number": 10,
    "health_periodic_audit_method": "NOVA_AUDIT",
    "vpc_id": "a8327883-6b07-4497-9c61-68d03ee193a",
    "available_zones": ["XXXa","XXXb"],
    "networks": [
        {
            "id": "3cd35bca-5a10-416f-8994-f79169559870"
        }
    ],
    "multi_az_priority_policy": "PICK_FIRST",

}

Response

Table 6 Response parameters

Parameter

Type

Description

scaling_group_id

String

Specifies the AS group ID.

Example Response

{
    "scaling_group_id": "a8327883-6b07-4497-9c61-68d03ee193a1"
}

Returned Values

  • Normal

    200

  • Abnormal

    Returned Value

    Description

    400 Bad Request

    The server failed to process the request.

    401 Unauthorized

    You must enter the username and password to access the requested page.

    403 Forbidden

    You are forbidden to access the requested page.

    404 Not Found

    The server could not find the requested page.

    405 Method Not Allowed

    You are not allowed to use the method specified in the request.

    406 Not Acceptable

    The response generated by the server could not be accepted by the client.

    407 Proxy Authentication Required

    You must use the proxy server for authentication to process the request.

    408 Request Timeout

    The request timed out.

    409 Conflict

    The request could not be processed due to a conflict.

    500 Internal Server Error

    Failed to complete the request because of an internal service error.

    501 Not Implemented

    Failed to complete the request because the server does not support the requested function.

    502 Bad Gateway

    Failed to complete the request because the request is invalid.

    503 Service Unavailable

    Failed to complete the request because the system is unavailable.

    504 Gateway Timeout

    A gateway timeout error occurred.

Error Codes

See Error Codes.