Trace Metrics

Use Trace Explorer to identify the root cause of an issue. As you define your query and determine what caused the problem you're investigating, you can create a trace metric from your query to display that metric in a dashboard for faster discovery. You can then configure monitors and alerts on that metric to notify other on-call engineers if that metric identifies anomalies in your trace data.

This ability to navigate from a trace metric to a specific query in Trace Explorer helps other on-call engineers address problems faster by using predefined queries to explore issues.

Use the following metric types to help track information for collected traces:

• Counter metric: Increments any time a trace that matches a filter gets collected. This metric also includes a label describing whether or not the trace contains an error.
• Histogram metric: Collects information about the distribution of request durations for traces that match a filter.

Chronosphere Observability Platform provides a default Trace Metrics dashboard with panels that display the requests, errors, and durations of requests associated with a created trace metric. The dashboard also includes a service map of the requests.

Observability Platform generates any trace metrics you've created before applying behaviors or tail sampling rules, which determine whether to persist the trace.

To explore tracing data in Observability Platform, you must either install and configure the Chronosphere Collector or the OpenTelemetry Collector to receive trace data from your services.

View existing trace metrics

You can view trace metrics in Observability Platform and open the related query in Trace Explorer.

To return a list of defined trace metrics without additional information, use Chronoctl.

Create a trace metric

Observability Platform uses trace queries as the basis for trace metrics. You define a search query in Trace Explorer, and create a trace metric based on the matching criteria.

You can search for any labels you add to your trace metric in Metrics Explorer when investigating query requests and responses.

Update a trace metric

Select from the following methods to update trace metrics.

Delete a trace metric

Select from the following methods to delete trace metrics.

Observability Platform removes the metric from the Trace Metrics page. Deleting a trace metric also removes access to the metric in the Trace Metrics dashboard.

Trace metric rule fields

A trace metric rule consists of the following fields, which are properties of the trace_metrics_rule object. Each field is required unless otherwise noted. See the CreateTraceMetricsRule (opens in a new tab) API for a complete list of supported fields.

• group_by: Labels for grouping and narrowing search results to specific attributes. See Group and narrow results for more information about grouping related attributes.

  • key: The key to group by.
    • named_key: The name of the key to group by.
    • type: The type of key to group by.
  • label: The dimension for displaying the aggregated results of your query grouped by that attribute in resulting trace metrics. Defaults to the selected service.

• histogram_buckets_seconds: Optional: An array of custom buckets measured in seconds for duration histogram metrics. You can set these if the default buckets aren't appropriate for your data. The default buckets are [0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1, 2.5, 5, 10].

• metric_labels: Optional: Static labels applied to the metrics, defined as an object of one or more label name/value pairs.

• metric_name: The metric's name as stored in the metrics database. Use this name to refer to the metric in PromQL queries, such as in dashboards, monitors, and the Metrics Explorer. The metric_name must follow Prometheus metric naming rules (opens in a new tab).

  Although you can modify the metric_name after creation, any data points generated before the name change aren't renamed. The new metric name is instead used to generate new data points starting from that point in time. The old metric name doesn't add new data, but you can still query it for past data points.

• name: The name of the trace metric rule. You can modify this name after creating the trace metric rule.

• slug: Optional: The slug for the trace metric rule. After you create the rule, the slug is immutable. If omitted, Observability Platform generates a slug at creation time that's based on the name.

• trace_filter: A filter object that evaluates traces against several criteria and emits metrics for only those that match. The filter's capabilities are similar to the filter in the Trace Explorer, except it supports only exact matches on string fields instead of regular expressions. This object supports additional optional object fields.

Optional trace filter object fields

The required trace_filter object supports the following optional fields, and you can use any combination of them:

• trace: Applies trace-level filtering. You can specify only one trace filter.

  • duration: Matches traces with a specified duration. You can specify only one of min_secs and max_secs.
    • min_secs: Matches traces with a duration greater than or equal to this value.
    • max_secs: Matches traces with a duration less than or equal to this value.
  • error: Object with a single field named value. If specified, matches traces with an error flag equal to this Boolean value. Refer to assign values with value for more information.

• span: Applies span-level filtering. You can specify multiple span filters, but Observability Platform evaluates a trace filter match only if all span filters match.

  • service: Object with a single field named value. Matches spans with a service field equal to this value. Refer to assign values with value for more information.
  • operation: Object with a single field named value. Matches spans with an operation field equal to this value. Refer to assign values with value for more information.
  • parent_service: Object with a single field named value. Matches spans whose parent span's service field is equal to this value. Refer to assign values with value for more information.
  • parent_operation: Object with a single field named value. Matches spans whose parent span's operation field is equal to this value. Refer to assign values with value for more information.
  • duration: Matches spans with a specified duration. You can specify only one of min_secs and max_secs.
    • min_secs: Matches spans with a duration greater than or equal to this value.
    • max_secs: Matches spans with a duration less than or equal to this value.
  • error: Object with a single field named value. If specified, matches traces with an error flag equal to this Boolean value. Refer to assign values with value for more information.
  • tags: Matches on a span's tag keys and values. You must specify the key, and you can specify multiple tag filters, but Observability Platform evaluates a span filter match only if all tag filters match.
  • key: Matches spans whose tags match the specified key.
  • value: Object with a single field named value. Matches spans when the tag with a matching key also matches the specified value. If omitted, Observability Platform evaluates all spans matching the key as matches. Refer to assign values with value for more information.
  • span_count: Specifies how many spans can match. You can set only one of min and max. By default, Observability Platform evaluates a span filter as a match only if at least one span matches.
    • min: If set, at least this number of spans must match the parent span filter's conditions for Observability Platform to evaluate the entire trace filter as a match.
    • max: If set, Observability Platform evaluates a trace filter match only if the number of spans matching the parent span filter's conditions is equal to or less than the max value.
  • match_type: Specifies the span filter's match type. Valid values are "include" and "exclude". The "include" match type is the default, and evaluates a trace filter match if all its fields match any span, or multiple spans if you specify a span_count. An "exclude" match type evaluates a trace filter match if no spans within that trace match all of the span filter's conditions.

Assign values with value

If a child field of a trace or span are objects with a single field named value, assign the value to the required child value field of these objects, instead of directly assigning the value like a field.

For example, to set the error field's value in a trace filter, use:

trace {
  error {
    value = true
  }
}

Also, the value of a tag filter, unlike the key, is also an object with a value field:

span {
  tag {
    key = "region"
    value = {
      value = "us-east"
    }
  }
}

Although these objects have only the one value field, this structure allows Chronosphere to plan future features for these criteria. For more examples of this structure, see the filter examples.

Filter examples

Matches traces marked as error that also took more than five seconds:

trace_filter {
    trace {
      duration {
        min_secs = 5
      }
      error {
        value = true
      }
    }
  }

Matches traces with at least one span from the service named "cupcake-factory":

trace_filter {
    span {
      service {
        value = "cupcake-factory"
      }
    }
  }

Matches traces with at least one span tagged region:us-east and at least one span tagged region:us-west:

trace_filter {
    span {
      tag {
        key = "region"
        value = {
          value = "us-east"
        }
      }
    }
    span {
      tag {
        key = "region"
        value = {
          value = "us-west"
        }
      }
    }
  }

Matches traces with at least one span tagged both region:us-east and stack:production:

trace_filter {
    span {
      tag {
        key = "region"
        value = {
          value = "us-east"
        }
      }
      tag {
        key = "stack"
        value = {
          value = "production"
        }
      }
    }

Matches traces with at least 10 spans containing the "db-query" operation:

trace_filter {
    span {
      operation {
        value = "db-query"
      }
      span_count {
        min = 10
      }
    }
  }