Metrics Selector

The Metrics Selector processor lets you choose which metrics to include or exclude, similar to the Grep filter for logs.

Configuration parameters

The Metrics Selector processor supports the following configuration parameters:

Key	Description	Default
metric_name	The string that determines which metrics are affected by this processor, depending on the active matching operation.
context	Specifies matching context. Possible values: metric_name or delete_label.	metrics_name
action	Specifies whether to include or exclude matching metrics. Possible values: INCLUDE or EXCLUDE.
operation_type	Specifies the matching operation to apply to the value of metric_name. Possible values: PREFIX or SUBSTRING.
label	Specifies a label key and value pair.

Matching operations

The Metrics Selector processor has two matching operations: prefix matching and substring matching.

Prefix matching

Prefix matching compares the value of metric_name to the beginning of each incoming metric name. For example, metric_name: fluentbit_input results in a match for metrics named fluentbit_input_records, but not for metrics named total_fluentbit_input.

If no operation_type value is specified and the value of metric_name is a standard string, the Metrics Selector processor defaults to prefix matching.

Substring matching

Substring matching treats the value of metric_name as a regex pattern, and compares this pattern against each incoming metric name accordingly. This pattern can appear anywhere within the name of the incoming metric. For example, metric_name: bytes results in a match for metrics named bytes_total and metrics named input_bytes_count.

If the value of metric_name is a string wrapped in forward slashes (for example, metric_name: /storage..*/), the Metrics Selector processor defaults to substring matching, regardless of whether an operation_type value is specified. This means that a metric_name value wrapped in forward slashes will always use substring matching, even if operation_type is set to PREFIX.

However, if operation_type is explicitly set to SUBSTRING, you don't need to wrap the value of metric_name in forward slashes.

Configuration examples

The following examples show possible configurations of the Metrics Selector processor.

Without context

service:
  flush: 5
  daemon: off
  log_level: info

pipeline:
  inputs:
    - name: fluentbit_metrics
      tag: fluentbit.metrics
      scrape_interval: 10

      processors:
        metrics:
          - name: metrics_selector
            metric_name: /storage/
            action: include
          - name: metrics_selector
            metric_name: /fs/
            action: exclude

          - name: labels
            delete: name


  outputs:
    - name: stdout
      match: '*'

With context

service:
  flush: 5
  daemon: off
  log_level: info

pipeline:
  inputs:
    - name: fluentbit_metrics
      tag: fluentbit.metrics
      scrape_interval: 10

      processors:
        metrics:
          - name: metrics_selector
            context: delete_label_value
            label: name stdout.0

          - name: labels
            delete: name


  outputs:
    - name: stdout
      match: '*'