Updated on 2022-12-14 GMT+08:00

Viewing Auto Scaling Policies

Function

This API is used to view all auto scaling policies of a specified cluster.

URI

GET /v2/{project_id}/autoscaling-policy/{cluster_id}

Table 1 URI parameters

Parameter

Mandatory

Type

Description

project_id

Yes

String

The project ID. For details about how to obtain the project ID, see Obtaining a Project ID.

cluster_id

Yes

String

The cluster ID. For details about how to obtain the cluster ID, see Obtaining a Cluster ID.

Request Parameters

None

Response Parameters

Status code: 200

Table 2 Response body parameter

Parameter

Type

Description

[Array element]

Array of AutoScalingPolicyV2 objects

The auto scaling policy list. For details, see Table 3.

Table 3 AutoScalingPolicyV2

Parameter

Type

Description

node_group_name

String

The node group name.

resource_pool_name

String

The resource plan name.

auto_scaling_policy

AutoScalingPolicy object

The auto scaling policy. For details, see Table 4.

Table 4 AutoScalingPolicy

Parameter

Type

Description

auto_scaling_enable

Boolean

Whether to enable the auto scaling policy.

min_capacity

Integer

The minimum number of nodes reserved in the node group. The value ranges from 0 to 500.

max_capacity

Integer

The maximum number of nodes in the node group. The value ranges from 0 to 500.

resources_plans

Array of ResourcesPlan objects

The resource plan list. If this parameter is left blank, the resource plan is disabled. When auto_scaling_enable is set to true, either this parameter or resources_plans must be configured. For details, see Table 5.

rules

Array of Rule objects

List of auto scaling rules. When auto_scaling_enable is set to true, either this parameter or resources_plans must be configured. For details, see Table 6.

exec_scripts

Array of ScaleScript objects

The list of custom scaling automation scripts. If this parameter is left blank, the automation script is disabled. For details, see Table 8.

Table 5 ResourcesPlan

Parameter

Type

Description

period_type

String

The cycle type of a resource plan. Currently, only the following cycle type is supported:

daily

start_time

String

The start time of a resource plan. The value is in the format of hour:minute, indicating that the time ranges from 00:00 to 23:59.

end_time

String

The end time of a resource plan. The value is in the same format as that of start_time. The interval between end_time and start_time must be greater than or equal to 30 minutes.

min_capacity

Integer

The minimum number of reserved nodes in a node group in a resource plan. The value ranges from 0 to 500.

max_capacity

Integer

The maximum number of reserved nodes in a node group in a resource plan. The value ranges from 0 to 500.

Table 6 Rule

Parameter

Type

Description

name

String

The name of an auto scaling rule. The name can contain only 1 to 64 characters. Only letters, numbers, hyphens (-), and underscores (_) are allowed. Rule names must be unique in a node group.

description

String

The description about an auto scaling rule. It contains a maximum of 1,024 characters.

adjustment_type

String

Auto scaling rule adjustment type. Possible values:

  • scale_out: cluster scale-out
  • scale_in: cluster scale-in

cool_down_minutes

Integer

The cluster cooling time after an auto scaling rule is triggered, when no auto scaling operation is performed. The unit is minute. The value ranges from 0 to 10080. One week is equal to 10,080 minutes.

scaling_adjustment

Integer

The number of cluster nodes that can be adjusted at a time. The value ranges from 1 to 100.

trigger

Trigger object

The condition for triggering a rule. For details, see Table 7.

Table 7 Trigger

Parameter

Type

Description

metric_name

String

The metric name. This triggering condition makes a judgment according to the value of the metric. A metric name contains a maximum of 64 characters.

metric_value

String

The metric threshold to trigger a rule.

The value must be an integer or a number with two decimal places.

comparison_operator

String

The metric judgment logic operator. Possible values:

  • LT: less than
  • GT: greater than
  • LTOE: less than or equal to
  • GTOE: greater than or equal to

evaluation_periods

Integer

The number of consecutive five-minute periods, during which a metric threshold is reached. The value ranges from 1 to 288.

Table 8 ScaleScript

Parameter

Type

Description

name

String

The name of a custom automation script. Names must be unique in a cluster. The value can contain only numbers, letters, spaces, hyphens (-), and underscores (_) and cannot start with a space. The value can contain 1 to 64 characters.

uri

String

The path of a custom automation script. Set this parameter to an OBS bucket path or a local VM path.

  • OBS bucket path: Enter a script path, for example, obs://XXX/scale.sh.
  • Local VM path: Enter a script path. The script path must start with a slash (/) and end with .sh.

parameters

String

Parameters of a custom automation script. Multiple parameters are separated by space. The following predefined system parameters can be transferred:

  • ${mrs_scale_node_num}: The number of nodes to be added or removed
  • ${mrs_scale_type}: The scaling type. The value can be scale_out or scale_in.
  • ${mrs_scale_node_hostnames}: Host names of the nodes to be added or removed
  • ${mrs_scale_node_ips}: IP addresses of the nodes to be added or removed
  • ${mrs_scale_rule_name}: The name of the rule that triggers scaling. Other user-defined parameters are used in the same way as those of common shell scripts. Parameters are separated by spaces.

nodes

Array of strings

The name of the node group where the custom automation script is executed.

active_master

Boolean

Whether the custom automation script runs only on the active master node. The default value is false, indicating that the custom automation script can run on all master nodes.

fail_action

String

Whether to continue executing subsequent scripts and creating a cluster after the custom automation script fails to execute. Notes:

  • You are advised to set this parameter to continue in the commissioning phase so the cluster can continue to be installed and started no matter whether the custom automation script is executed successfully.
  • The scale-in operation cannot be undone. fail_action must be set to continue for the scripts that are executed after scale-in. Possible values:
  • continue: Continue to execute subsequent scripts.
  • errorout: Stop the action.

action_stage

String

The time when a script is executed. Possible values:

  • before_scale_out: before scale-out
  • before_scale_in: before scale-in
  • after_scale_out: after scale-out
  • after_scale_in: after scale-in

Status code: 400

Table 9 Response body parameters

Parameter

Type

Description

error_code

String

Error codes.

error_msg

String

The error message.

Example Request

None

Example Response

Status code: 200

Auto scaling policies are displayed.

[ {
  "node_group_name" : "task_node_analysis_group",
  "resource_pool_name" : "default",
  "auto_scaling_policy" : {
    "auto_scaling_enable" : true,
    "min_capacity" : 0,
    "max_capacity" : 1,
    "resources_plans" : [ {
      "period_type" : "daily",
      "start_time" : "12:00",
      "end_time" : "13:00",
      "min_capacity" : 2,
      "max_capacity" : 3
    } ],
    "rules" : [ {
      "name" : "default-expand-1",
      "description" : "",
      "adjustment_type" : "scale_out",
      "cool_down_minutes" : 5,
      "scaling_adjustment" : 1,
      "trigger" : {
        "metric_name" : "YARNAppRunning",
        "metric_value" : 100,
        "comparison_operator" : "GTOE",
        "evaluation_periods" : 1
      }
    } ]
  }
} ]

Status Codes

See Status Codes.

Error Codes

See Error Codes.