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metric

Emit custom metrics by extracting values from messages.

# Config fields, showing default values
label: ""
metric:
  type: "" # No default (required)
  name: "" # No default (required)
  labels: {} # No default (optional)
  value: ""

This processor works by evaluating an interpolated field value for each message and updating a emitted metric according to the type.

Custom metrics such as these are emitted along with Bento internal metrics, where you can customize where metrics are sent, which metric names are emitted and rename them as/when appropriate. For more information check out the metrics docs here.

Fields​

type​

The metric type to create.

Type: string
Options: counter, counter_by, gauge, timing.

name​

The name of the metric to create, this must be unique across all Bento components otherwise it will overwrite those other metrics.

Type: string

labels​

A map of label names and values that can be used to enrich metrics. Labels are not supported by some metric destinations, in which case the metrics series are combined. This field supports interpolation functions.

Type: object

# Examples

labels:
  topic: ${! meta("kafka_topic") }
  type: ${! json("doc.type") }

value​

For some metric types specifies a value to set, increment. Certain metrics exporters such as Prometheus support floating point values, but those that do not will cast a floating point value into an integer. This field supports interpolation functions.

Type: string
Default: ""

Examples​

In this example we emit a counter metric called Foos, which increments for every message processed, and we label the metric with some metadata about where the message came from and a field from the document that states what type it is. We also configure our metrics to emit to CloudWatch, and explicitly only allow our custom metric and some internal Bento metrics to emit.

pipeline:
  processors:
    - metric:
        name: Foos
        type: counter
        labels:
          topic: ${! meta("kafka_topic") }
          partition: ${! meta("kafka_partition") }
          type: ${! json("document.type").or("unknown") }

metrics:
  mapping: |
    root = if ![
      "Foos",
      "input_received",
      "output_sent"
    ].contains(this) { deleted() }
  aws_cloudwatch:
    namespace: ProdConsumer

Types​

counter​

Increments a counter by exactly 1, the contents of value are ignored by this type.

counter_by​

If the contents of value can be parsed as a positive integer value then the counter is incremented by this value.

For example, the following configuration will increment the value of the count.custom.field metric by the contents of field.some.value:

pipeline:
  processors:
    - metric:
        type: counter_by
        name: CountCustomField
        value: ${!json("field.some.value")}

gauge​

If the contents of value can be parsed as a positive integer value then the gauge is set to this value.

For example, the following configuration will set the value of the gauge.custom.field metric to the contents of field.some.value:

pipeline:
  processors:
    - metric:
        type: gauge
        name: GaugeCustomField
        value: ${!json("field.some.value")}

timing​

Equivalent to gauge where instead the metric is a timing. It is recommended that timing values are recorded in nanoseconds in order to be consistent with standard Bento timing metrics, as in some cases these values are automatically converted into other units such as when exporting timings as histograms with Prometheus metrics.