# 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 | 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 range is 0 to 200.
  - If operation is set to ADD, REMOVE, or REDUCE, the value range is 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 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.

#### Error Codes

See Error Codes.

Parent topic: AS Policies