AOM allows you to subscribe to metrics or alarms. After the subscription, data can be forwarded to custom Kafka or Distributed Message Service (DMS) topics for you to retrieve.

A maximum of 10 data subscription rules can be created.

Creating Subscription Rules

Click Create Subscription Rule in the upper right corner. On the displayed page, set parameters and click OK.

You can set Subscription Target Type to Custom Kafka or DMS as required.

If Subscription Target Type is set to Custom Kafka, set parameters based on Table 1.

**Table 1** Subscription rule parameters
Parameter	Description	Example
Rule Name	Subscription rule name.	Enter aom-kafka-test.
Subscription Content	Options: Metric and Alarm.	Select Metric.
Subscription Target Type	Options: Custom Kafka and DMS.	Select Custom Kafka.
Subscription Target Address	Custom Kafka address, which needs to be connected to Internet. Each address must be in the format of "IPv4 address:port". If multiple addresses exist, separate them by commas (,). Example: 192.168.0.1:9092,192.168.0.2:9092	Set this parameter as required.

(Optional) On the Rule Details page, click

to enable Kafka SASL_SSL and set parameters based on Table 2.

AOM supports only Kafka SASL_SSL security authentication. If you have enabled Kafka SASL_SSL for instances, you also need to enable it on the Rule Details page.

**Table 2** Setting Kafka SASL_SSL parameters
Parameter	Description	Example
User name	SASL username for instance access authentication.	demo
Password	SASL password for instance access authentication. Keep your password secure. The system cannot detect your password.	-
Client certificate	Use a client certificate in .pem format.	-

Click Verify and Save Custom Kafka Configuration to verify the connectivity of the custom Kafka instance.
Select a topic for transmitting data and click OK.

If Subscription Target Type is set to DMS, set parameters based on Table 3.

**Table 3** Subscription rule parameters
Parameter	Description	Example
Rule Name	Subscription rule name.	Enter aom-kafka-test.
Subscription Content	Options: Metric and Alarm.	Select Metric.
Subscription Target Type	Options: Custom Kafka and DMS.	Select DMS.
Instance	Select a DMS instance. If no DMS instance is available, click Create DMS Instance to create one.	Select kafka-aom-7160.

On the Rule Details page, click Create a network connection channel.
Verify the DMS instance connectivity.
Ensure that an inbound rule is added to allow traffic from source IP address 198.19.128.0/20 on port 9011. To set a security group rule, do as follows:
1. Log in to the management console.
2. Click in the upper left corner and choose Networking > Virtual Private Cloud.
3. In the navigation pane, choose Access Control > Security Groups. Then, locate the security group corresponding to the DMS instance and click Manage Rule in the Operation column.
4. On the Inbound Rules tab page, click Add Rule to allow the network traffic from source IP address 198.19.128.0/20 on port 9011.
Click Verify and Save DMS Configuration Information.
Select a topic for transmitting data and click OK.

Data Subscription Format

Metric data example (in JSON format)

package metric

type MetricDatas struct {
   Metrics   []Metrics `json:"metrics"`
   ProjectId string    `json:"project_id"`
}

type Metrics struct {
   Metric      Metric  `json:"metric"`
   Values      []Value `json:"values"`
   CollectTime int64   `json:"collect_time"`
}

type Metric struct {
   Namespace  string      `json:"namespace"`
   Dimensions []Dimension `json:"dimensions"`
}

type Value struct {
   Value           interface{} `json:"value"`
   Type            string      `json:"type"`
   Unit            string      `json:"unit"`
   StatisticValues string      `json:"statisticvalues"`
   MetricName      string      `json:"metric_name"`
}

type Dimension struct {
   Name  string `json:"name"`
   Value string `json:"value"`
}

Kafka message example

key:,
value:{"metrics":[{"metric":{"namespace":"PAAS.NODE","dimensions":[{"name":"nodeName","value":"test-vss-cop-master-1"},{"name":"nodeIP","value":"1.1.1.1"},{"name":"hostID","value":"75d97111-4734-4c6c-ae9e-f6111111111"},{"name":"nameSpace","value":"default"},{"name":"clusterId","value":"46a7bc0d-1d8b-11ea-9b04-333333333333333"},{"name":"clusterName","value":"test-vss-111"},{"name":"diskDevice","value":"vda"},{"name":"master","value":"true"}]},"values":[{"value":0,"type":"","unit":"Kilobytes/Second","statisticvalues":"","metric_name":"diskReadRate"},{"value":30.267,"type":"","unit":"Kilobytes/Second","statisticvalues":"","metric_name":"diskWriteRate"}],"collect_time":1597821030037}],"project_id":"111111111111111111111"}

Alarm data format

Example:

{
    "events": [{
        "id": "4346299651651991683",
        "starts_at": 1597822250194,
        "ends_at": 0,
        "arrives_at": 1597822250194,
        "timeout": 300000,
        "resource_group_id": "312313123112222222222232131312131",
        "metadata": {
            "kind": "Pod",
            "event_severity": "Major",
            "resource_type": "service",
            "clusterId": "6add4ef5-1358-11ea-a5bf-111111111",
            "event_type": "alarm",
            "clusterName": "cce-ief-4516140c-96ca-4a5f-8d85-1111111",
            "namespace": "PAAS.NODE",
            "name": "test15769793809553052-f5557bd7f-qnfkm",
            "event_name": "FailedScheduling",
            "resource_id": "clusterName=cce-ief-4516140c-96ca-4a5f-8d85-111111;clusterID=6add4ef5-1358-11ea-a5bf-11111111111;kind=Pod;namespace=30d5758f166947c6b164af604a654b09;name=test15769793809553052-f5557bd7f-qnfkm;uid=589fc746-245d-11ea-a465-fa163e5fc15d",
            "nameSpace": "30d5758f166947c6b164af604a654b09",
            "resource_provider": "CCE",
            "nodeID": "589fc746-245d-11ea-a465-fa163e5fc15d"
        },
        "annotations": {
            "alarm_probableCause_zh_cn": "FailedScheduling",
            "alarm_probableCause_en_us": "FailedScheduling",
            "message": "0/110 nodes are available: 1 node(s) had taints that the pod didn't tolerate, 109 node(s) didn't match node selector."
        },
        "attach_rule": {
            
        }
    }],
    "project_id": "312313123112222222222232131312131"
}

Parameter description:

**Table 4** Alarm parameters
Parameter	Type	Description
events	Array of objects. For details, see Table 5.	Event or alarm details.
project_id	String	Project ID obtained from IAM. Generally, a project ID contains 32 characters.

**Table 5** EventModel
Parameter	Type	Description
id	String	Event or alarm ID, which is automatically generated by the system.
starts_at	Long	Time when an event or alarm is generated. The value is a China Standard Time (CST) timestamp precise down to the millisecond.
ends_at	Long	Time when an event or alarm is cleared. The value is a CST timestamp precise down to the millisecond. If the value is 0, the event or alarm is not deleted.
arrives_at	Long	Time when an event or alarm reaches AOM. The value is a CST timestamp precise down to the millisecond.
timeout	Long	Duration (unit: ms) at which an alarm is automatically cleared. For example, if the duration is one minute, set this parameter to 60000. The default duration is three days.
resource_group_id	String	Reserved field for a resource group. The default value is the same as the value of projectid.
metadata	Object	Details of an event or alarm. The value is a key-value pair. The following fields are mandatory: event_name: Event or alarm name, which is a string. event_severity: Event severity, which is an enumerated value with the string-type attribute. Options: Critical, Major, Minor, and Info. event_type: Event type, which is an enumerated value with the string-type attribute. Options: event and alarm. resource_provider: Name of a cloud service corresponding to an event, which is a string. resource_type: Resource type corresponding to an event, which is a string. resource_id: Resource ID corresponding to an event, which is a string.
annotations	Object	Additional field for an event or alarm, which can be left blank.
attach_rule	Object	Reserved field for an event or alarm, which can be left blank.

Follow-up Operations

After the data subscription rule is created, AOM will send data to your custom Kafka or DMS topic so that you can retrieve the subscribed metrics or alarms.