Edge Delta Extract Metric Processor

The Edge Delta extract metric processor generates metrics from other data items.

5 minute read

Overview

The extract metric processor converts a data item into a metric item and uses one of its fields as the metric. This is useful if your data item already contains a useful metric.

See Extract and Aggregate Metrics for more information about using the extract metric processor.

For detailed instructions on how to use multiprocessors, see Use Multiprocessors.

Example Input

Consider this log:

{
  "_type": "log",
  "timestamp": 1744873926928,
  "body": "{\"timestamp\": \"2025-04-17T07:12:05.923408Z\", \"level\": \"Alert\", \"msg\": \"processing failed\", \"user\": {\"email\": \"wang.xiu@mymailservice.com\", \"id\": \"96dd851f-e791-4388-98c7-cbb7e3df50b2\", \"name\": \"08ecbb0d-a961-4c8a-8db0-040e537257af\"}, \"request\": {\"ip\": \"172.24.16.218\", \"method\": \"DELETE\", \"path\": \"/json/view\"}, \"status\": 500, \"response_time_ms\": 7837}",
  "resource": {
    ...
  },
  "attributes": {
    "level": "Alert",
    "msg": "processing failed",
    "request": {
      "ip": "172.24.16.218",
      "method": "DELETE",
      "path": "/json/view"
    },
    "response_time_ms": 7837,
    "status": 500,
    "timestamp": "2025-04-17T07:12:05.923408Z",
    "user": {
      "email": "wang.xiu@mymailservice.com",
      "id": "96dd851f-e791-4388-98c7-cbb7e3df50b2",
      "name": "08ecbb0d-a961-4c8a-8db0-040e537257af"
    }
  }
}

Note: The body is JSON that has been parsed into attributes.

Suppose you want to monitor the count of HTTP response codes across all logs. You can convert the log into a metric focused on the status attribute.

Configuration

In this example, the extract metric processor creates a gauge type metric with a count of unique values found in the attributes["status"] field

The corresponding YAML is as follows (without the parse JSON processor).

- name: kubernetes_input_jt1iw_multiprocessor
  type: sequence
  processors:
  - type: extract_metric
    metadata: '{"id":"_rK4ucX4G8oDcrXWwXh2r","type":"extract_metric","name":"Extract
      Metric"}'
    extract_metric_rules:
    - name: status_code
      description: A count of each unique status code
      unit: "1"
      gauge:
        value: attributes["status"]

Example Output

This results in metrics such as the following:

{
  "_type": "metric",
  "timestamp": 1744875106543,
  "resource": {
    ...
  },
  "attributes": {
    "level": "Info",
    "msg": "processing succeeded",
    "request": {
      "ip": "10.192.49.15",
      "method": "GET",
      "path": "/json/view"
    },
    "response_time_ms": 255,
    "status": 200,
    "timestamp": "2025-04-17T07:31:43.684354Z",
    "user": {
      "email": "jane.smith@demomail.com",
      "id": "110abee8-d4e5-4a80-8984-54dc1c04930f",
      "name": "7b982abe-a8fe-4429-9c8f-30e3692f8caa"
    }
  },
  "description": "A count of each unique status code",
  "gauge": {
    "value": 200
  },
  "kind": "gauge",
  "name": "status_code",
  "unit": "1",
  "_stat_type": "value"
}

Note how the attributes have been adopted from the parent log. This will be useful for later aggregation with dimension groups, for example, using the aggregate metric processor.

Options

Select a telemetry type

You can specify, log, metric, trace or all. It is specified using the interface, which generates a YAML list item for you under the data_types parameter. This defines the data item types against which the processor must operate. If data_types is not specified, the default value is all. It is optional.

It is defined in YAML as follows:

- name: multiprocessor
  type: sequence
  processors:
  - type: <processor type>
    data_types:
    - log

Condition

The condition parameter contains a conditional phrase of an OTTL statement. It restricts operation of the processor to only data items where the condition is met. Those data items that do not match the condition are passed without processing. You configure it in the interface and an OTTL condition is generated. It is optional. You can select one of the following operators:

Operator	Name	Description	Example
`==`	Equal to	Returns `true` if both values are exactly the same	`attributes["status"] == "OK"`
`!=`	Not equal to	Returns `true` if the values are not the same	`attributes["level"] != "debug"`
`>`	Greater than	Returns `true` if the left value is greater than the right	`attributes["duration_ms"] > 1000`
`>=`	Greater than or equal	Returns `true` if the left value is greater than or equal to the right	`attributes["score"] >= 90`
`<`	Less than	Returns `true` if the left value is less than the right	`attributes["load"] < 0.75`
`<=`	Less than or equal	Returns `true` if the left value is less than or equal to the right	`attributes["retries"] <= 3`
`matches`	Regex match	Returns `true` if the string matches a regular expression	`isMatch(attributes["name"], ".*\\.name$"`

It is defined in YAML as follows:

- name: _multiprocessor
  type: sequence
  processors:
  - type: <processor type>
    condition: attributes["request"]["path"] == "/json/view"

Add Rule

Click to add additional metrics to extract. One metric is generated for each rule per data item.

Metric Name

Define a name for the metric.

Description

Provide a description for the metric. This is added to the metric item in the description field.

Unit

Select Count or Bytes as the unit of measurement.

Conditions

The conditions parameter is a child of the metric definition. It contains a conditional phrase of an OTTL statement. It restricts operation of the processor to only data items where the condition is met, for the parent metric. This is different to the condition parameter which toggles the entire processor. Those data items that do not match the condition are passed without a metric being generated (other metrics in the same processor might still be created). It is specified by the tool as an OTTL condition when you select the condition fields in the interface and it is optional.

It is defined in YAML as follows:

- name: _multiprocessor
  type: sequence
  processors:
  - type: <processor type>
    aggregate_metric_rules:
    - name: <metric name>
      conditions:
      - attributes["level"] = Error

Final

The final parameter specifies whether successfully processed data items should continue to subsequent processors within the same multiprocessor node. Data items that fail to be processed by the processor will be passed to the next processor in the node regardless of this setting. You select the slider in the tool which specifies it for you in the YAML as a Boolean. The default is false and it is optional.

It is defined in YAML as follows:

- name: multiprocessor
  type: sequence
  processors:
    - type: <processor type>
    final: true

Keep original telemetry item

This option defines whether to delete the original unmodified data item after it is processed. For example, you can keep the original log as well as any metrics generated by an extract metric processor. If you select this option your data volume will increase.