Modifying a Policy

Function

This API is used to modify a policy.

Alarm policies can be modified, but scheduled and periodic policies cannot.

URI

PUT /v1/{project_id}/pe/policy/{policy_id}

Table 1 describes the parameters.

**Table 1** Parameters
Parameter	Mandatory	Description
project_id	Yes	Project ID.
policy_id	Yes	Policy ID.

Request

Request headers

Table 2 describes the request headers.

**Table 2** Request headers
Parameter	Description	Mandatory	Example
Content-Type	Content type, which is application/json;charset=utf-8.	Yes	application/json;charset=utf-8
Cluster-Id	Cluster ID.	Yes	-
Namespace	Namespace.	Yes	-
Deployment-Name	Application name.	Yes	-

Request parameters

Table 3 describes the request parameters.

**Table 3** Request parameters
Parameter	Mandatory	Type	Value Range	Description
id	Yes	String	-	Policy ID.
name	Yes	String	The value must be 1 to 64 characters starting with a letter. Only digits, letters, underscores (_), and hyphens (-) are allowed.	Policy name, which cannot be modified.
policy_type	Yes	String	ALARM	Policy type. Currently, only ALARM policies are supported.
rule	Yes	See Table 4.	-	Policy trigger rule.

**Table 4** rule parameters
Parameter	Mandatory	Type	Value Range	Description
conditions	Yes	See Table 5.	1–5	Condition contents. A rule can contain multiple conditions in AND relationships. One condition describes the matching method of one metric.
actions	Yes	See Table 6.	1–5	Action executed after a specified policy is successfully matched.

**Table 5** conditions parameters
Parameter	Mandatory	Type	Value Range	Description
metric_namespace	Yes	String	PAAS.CONTAINER: application metric namespace. PAAS.CUSTOMMETRICS: custom metric namespace.	Metric namespace.
metric_name	Yes	String	The value must be 1 to 255 characters long and meet the [a-zA-Z_:][a-zA-Z0-9_:]* expression. That is, the value must start with a letter, underscore (_), or colon (:). Only letters, digits, underscores, and colons are allowed.	Metric name.
metric_unit	Yes	String	-	Unit. NOTE: The value is retrieved from an AMS API and varies with the metric name.
period	Yes	Integer	20, 60, 300, 900, 1800, or 3600	Statistical period (unit: s).
evaluation_periods	Yes	Integer	1, 2, 3, 4, or 5	Number of consecutive periods.
statistic	Yes	String	Currently, only average is supported.	Statistic.
metric_operation	Yes	String	> and <. For example, you can use > in a threshold criterion (when the value of a metric is greater than metric_thresholdUpdate) to trigger actions.	Metric operator.
metric_threshold	Yes	Float	[0, 2147483647]	Threshold criterion.

**Table 6** actions parameters
Parameter	Mandatory	Type	Value Range	Description
type	Yes	String	scale_out_k8s scale_out_vm scale_in_k8s scale_in_vm	scale_out_k8s and scale_out_vm indicate a scale-out. scale_in_k8s and scale_in_vm indicate a scale-in. NOTE: The value containing k8s indicates a container application and that containing vm indicates a process application.
parameters	Yes	See Table 7.	-	Number of scale-in or -out instances.

**Table 7** parameters
Parameter	Mandatory	Type	Value Range	Description
scale_unit	Yes	Integer	Minimum number of instances to the maximum number of instances in a policy group.	Number of scale-in or -out instances.

Example request

Example of an alarm policy

{   
    "id" : "5c2eecea-32ac-42c0-be30-f73b15d68429", 
    "name" : "policy_1", 
    "policy_type" : "ALARM", 
    "rule" : { 
        "conditions" : [{ 
                "metric_namespace" : "PAAS.CONTAINER", 
                "metric_name" : "cpuUsage", 
                "metric_unit" : "Percent", 
                "period" : 60, 
                "evaluation_periods" : 1, 
                "statistic" : "average", 
                "metric_operation" : ">", 
                "metric_threshold" : 70 
            } 
        ], 
        "actions" : [{ 
                "type" : "scale_out_k8s", 
                "parameters" : { 
                    "scale_unit" : 1 
                } 
            } 
        ] 
    } 
}

Response

Response parameters

Table 8 describes the response parameters.

**Table 8** Response parameters
Parameter	Type	Description
errorCode	String	Error code.
errorMessage	String	Error details.
context	String	Details about a modified policy.

Example response

{
   "errorCode": 0,  
   "errorMessage": "",
   "context": { 
        "id" : "5c2eecea-32ac-42c0-be30-f73b15d68429", 
        "name" : "policy_1", 
        "policy_type" : "ALARM", 
        "rule" : { 
            "conditions" : [{ 
                    "metric_namespace" : "PAAS.CONTAINER", 
                    "metric_name" : "cpuUsage", 
                    "metric_unit" : "Percent", 
                    "period" : 60, 
                    "evaluation_periods" : 1, 
                    "statistic" : "average", 
                    "metric_operation" : ">", 
                    "metric_threshold" : 70 
                } 
            ], 
            "actions" : [{ 
                    "type" : "scale_out_k8s", 
                    "parameters" : { 
                        "scale_unit" : 1 
                    }   
                } 
            ] 
        } 
    } 
}

Error Code

**Table 9** Error codes
Error Code	Message	Solution
SVCSTG.PE.4001101	Invalid parameter.	Check whether the parameter meets requirements.
SVCSTG.PE.4031012	Failed to verify the project ID.	Check whether the parameter meets requirements.
SVCSTG.PE.4033008	Failed to update the scheduled or periodic policy.	Check whether the parameter meets requirements.
SVCSTG.PE.5001201	Failed to insert or update data in the background.	Contact technical support.
SVCSTG.PE.5001203	Query error.	Contact technical support.
SVCSTG.PE.5003007	Failed to update the threshold rule.	Contact technical support.