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 Message

Request parameters

**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	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	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 range is 0 to 300. If operation is set to ADD, REMOVE, or REDUCE, the value range is 1 to . 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 of this parameter 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 shows how to create a periodic AS policy named as-policy-7a75. The policy takes effect from 2015-12-14T03:34Z through 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 Message

Response parameters

**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 so that the request can be processed.
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.