Creating an AS Policy

Function

This API is used to create an AS policy.

  • An AS policy defines whether to increase or decrease the number of instances in an AS group. If the number and the expected number of instances in an AS group are different due to the execution of the AS policy, AS automatically adjusts the number of instances to the expected.

  • AS supports the following policies: alarm-triggered policy, periodic policy, and scheduled policy.

  • In the execution of the AS policy, you can set the number of instances to be scaled or perform a scaling action according to a percentage specified in the AS policy.

URI

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

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_policy_name

Yes

String

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

scaling_group_id

Yes

String

Specifies the AS group ID, which can be obtained using the API for querying AS groups. For details, see Querying AS Groups.

scaling_policy_type

Yes

String

Specifies the AS policy type.

  • ALARM (corresponding to alarm_id): indicates that the scaling action is triggered by an alarm.

  • SCHEDULED (corresponding to scheduled_policy): indicates that the scaling action is triggered as scheduled.

  • RECURRENCE (corresponding to scheduled_policy): indicates that the scaling action is triggered periodically.

alarm_id

No

String

Specifies the alarm rule ID. This parameter is mandatory when scaling_policy_type is set to ALARM. After this parameter is specified, the value of scheduled_policy does not take effect.

After you create an alarm policy, the system automatically adds an alarm triggering activity of the autoscaling type to the alarm_actions field in the alarm rule specified by the parameter value.

scheduled_policy

No

scheduled_policy object

Specifies the periodic or scheduled AS policy. This parameter is mandatory when scaling_policy_type is set to SCHEDULED or RECURRENCE. After this parameter is specified, the value of alarm_id does not take effect. For details, see Table 3.

scaling_policy_action

No

scaling_policy_action object

Specifies the scaling action of the AS policy. For details, see Table 4.

cool_down_time

No

Integer

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

Table 3 scheduled_policy field description

Parameter

Mandatory

Type

Description

launch_time

Yes

String

Specifies the time when the scaling action is triggered. The time format complies with UTC.

  • If scaling_policy_type is set to SCHEDULED, the time format is YYYY-MM-DDThh:mmZ.

  • If scaling_policy_type is set to RECURRENCE, the time format is hh:mm.

recurrence_type

No

String

Specifies the periodic triggering type. This parameter is mandatory when scaling_policy_type is set to RECURRENCE.

  • Daily: indicates that the scaling action is triggered once a day.

  • Weekly: indicates that the scaling action is triggered once a week.

  • Monthly: indicates that the scaling action is triggered once a month.

recurrence_value

No

String

Specifies the day when a periodic scaling action is triggered. This parameter is mandatory when scaling_policy_type is set to RECURRENCE.

  • If recurrence_type is set to Daily, the value is null, indicating that the scaling action is triggered once a day.

  • If recurrence_type is set to Weekly, the value ranges from 1 (Sunday) to 7 (Saturday). The digits refer to dates in each week and separated by a comma, such as 1,3,5.

  • If recurrence_type is set to Monthly, the value ranges from 1 to 31. The digits refer to the dates in each month and separated by a comma, such as 1,10,13,28.

start_time

No

String

Specifies the start time of the scaling action triggered periodically. The time format complies with UTC. The default value is the local time.

The time format is YYYY-MM-DDThh:mmZ.

end_time

No

String

Specifies the end time of the scaling action triggered periodically. The time format complies with UTC. This parameter is mandatory when scaling_policy_type is set to RECURRENCE.

When the scaling action is triggered periodically, the end time cannot be earlier than the current and start time.

The time format is YYYY-MM-DDThh:mmZ.

Table 4 scaling_policy_action field description

Parameter

Mandatory

Type

Description

operation

No

String

Specifies the operation to be performed. The default operation is ADD.

  • ADD: adds specified number of instances to the AS group.

  • REMOVE/REDUCE: removes or reduces specified number of instances from the AS group.

  • SET: sets the number of instances in the AS group.

instance_number

No

Integer

Specifies the number of instances to be operated. The default number is 1. The value range is as follows for a default quota:

  • If operation is set to SET, the value ranges from 0 to 200.

  • If operation is set to ADD, REMOVE, or REDUCE, the value ranges from 1 to 200.

Note

Either instance_number or instance_percentage is required.

instance_percentage

No

Integer

Specifies the percentage of instances to be operated. You can increase, decrease, or set the number of instances in an AS group to the specified percentage of the current number of instances. If operation is set to ADD, REMOVE or REDUCE, the value is an integer from 1 to 20000. If operation is set to SET, the value is an integer from 0 to 20000.

If neither instance_number nor instance_percentage is specified, the number of instances to be operated is 1.

Either instance_number or instance_percentage is required.

Example Request

This example creates a periodic AS policy named as-policy-7a75. The policy takes effect from 2015-12-14T03:34Z to 2015-12-27T03:34Z. During this period, one instance will be added to AS group with ID 5bc3aa02-b83e-454c-aba1-4d2095c68f8b at 16:00 every day.

POST https://{Endpoint}/autoscaling-api/v1/{project_id}/scaling_policy

{
    "scaling_policy_name": "as-policy-7a75",
    "scaling_policy_action": {
        "operation": "ADD",
        "instance_number": 1
    },
    "cool_down_time": 900,
    "scheduled_policy": {
        "launch_time": "16:00",
        "recurrence_type": "Daily",
        "start_time": "2015-12-14T03:34Z",
        "end_time": "2015-12-27T03:34Z"
    },
    "scaling_policy_type": "RECURRENCE",
    "scaling_group_id": "5bc3aa02-b83e-454c-aba1-4d2095c68f8b"
}

Response

Table 5 Response parameters

Parameter

Type

Description

scaling_policy_id

String

Specifies the AS policy ID.

Example Response

{
    "scaling_policy_id": "0h327883-324n-4dzd-9c61-68d03ee191dd"
}

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.