Aggregates Request, Error and Duration (R.E.D) OpenTelemetry metrics from span data.

Request counts are computed as the number of spans seen per unique set of dimensions, including Errors. Multiple metrics can be aggregated if, for instance, a user wishes to view call counts just on service.name and span.name.

Error counts are computed from the Request counts which have an Error Status Code metric dimension.

Duration is computed from the difference between the span start and end times and inserted into the relevant duration histogram time bucket for each unique set dimensions.

Each metric will have at least the following dimensions because they are common across all spans:

• service.name
• span.name
• span.kind
• status.code

If you are not already familiar with connectors, you may find it helpful to first visit the Connectors README.

The following settings can be optionally configured:

• histogram (default: explicit_buckets): Use to configure the type of histogram to record calculated from spans duration measurements.

  • unit (default: ms, allowed values: ms, s): The time unit for recording duration measurements. calculated from spans duration measurements.
  • explicit:
    • buckets: the list of durations defining the duration histogram buckets. Default buckets: [2ms, 4ms, 6ms, 8ms, 10ms, 50ms, 100ms, 200ms, 400ms, 800ms, 1s, 1400ms, 2s, 5s, 10s, 15s]
  • exponential:
    • max_size (default: 160) the maximum number of buckets per positive or negative number range.

• latency_histogram_buckets (deprecated): the list of durations defining the latency histogram buckets.

  • Default: [2ms, 4ms, 6ms, 8ms, 10ms, 50ms, 100ms, 200ms, 400ms, 800ms, 1s, 1400ms, 2s, 5s, 10s, 15s]

• dimensions: the list of dimensions to add together with the default dimensions defined above.

  Each additional dimension is defined with a name which is looked up in the span's collection of attributes or resource attributes (AKA process tags) such as ip, host.name or region.

  If the named attribute is missing in the span, the optional provided default is used.

  If no default is provided, this dimension will be omitted from the metric.

• dimensions_cache_size: the max items number of metric_key_to_dimensions_cache. If not provided, will use default value size 1000.

• aggregation_temporality: Defines the aggregation temporality of the generated metrics. One of either AGGREGATION_TEMPORALITY_CUMULATIVE or AGGREGATION_TEMPORALITY_DELTA.

  • Default: AGGREGATION_TEMPORALITY_CUMULATIVE

• namespace: Defines the namespace of the generated metrics. If namespace provided, generated metric name will be added namespace. prefix.

The following is a simple example usage of the spanmetrics connector.

For configuration examples on other use cases, please refer to More Examples.

The full list of settings exposed for this connector are documented here.

receivers:
  nop:

exporters:
  nop:

connector:
  spanmetrics:
    histogram:
      explicit:
        buckets: [100us, 1ms, 2ms, 6ms, 10ms, 100ms, 250ms]
    dimensions:
      - name: http.method
        default: GET
      - name: http.status_code
    dimensions_cache_size: 1000
    aggregation_temporality: "AGGREGATION_TEMPORALITY_CUMULATIVE"     

service:
  pipelines:
    traces:
      receivers: [nop]
      exporters: [spanmetrics]
    metrics:
      receivers: [spanmetrics]
      exporters: [nop]

For more example configuration covering various other use cases, please visit the testdata directory.